MAY 31ST OKLAHOMA - THE EL RENO EF3 TORNADO

July 09, 2013 by Brad in 2013

First getting on the approaching storm roughly 3 miles southeast of El Reno, directly east-northeast of the already large tornado. Tornado tough to pick out at the time due to what looked like a large hail/rain core underneath.

On the north side of the storm, well defined feeder inflow bands sucking in the rich low level moisture. Even mid-level moisture bands can be seen spiraling into the intense supercell. Tornado on the left underneath the storm updraft.

Can clearly pick out the wedge tornado underneath the impressive structured supercell at this time.

Taken over my right shoulder as we were bailing south to get out of the way. Stopped only for a brief moment to look back and snap the photo as this was the closest we came to the monster tornado.

Tornado begins to get even larger and take a hard left turn towards I-40 as we watched from SW 15th St and Evans St.

Another shot looking north-northwest as the tornado was starting to move by us and go over I-40, becoming even larger and picking up speed in the process.

Had to crank up the contrast here, but I believe this is close to when the tornado was at its largest. Reported as large as 2.6 miles wide! Notice the entire mesocyclone now on the ground.

Another shot of the incredibly massive tornado in the distance as it was moving away and wrapping into the supercell.

Incredible phased array radar imagery of the tornadic supercell that spawned the powerful, massive tornado.

RAXPOL radar imagery. Notice in the DBZ and VEL imagery how clearly you can see the main tornado and the satellite tornado. ZDR clearly shows large debris ball with foreign objects to the radar indicated in green and blue.

STORM REPORTS:

STORM PREDICTION CENTER OUTLOOKS:

MAY 31, 2013 CHASE LOG: OKLAHOMA

Rest in Peace and God Bless Tim and Paul Samaras, Carl Young, and others who lost their lives to this tornado.

The El Reno Tornado will go down as one of the most remembered tornadoes in history and the largest tornado ever recorded to date. This tornado was originally classified as an EF-5 with winds of 296 mph based on mobile radar, but has since been corrected down to an EF3 based on damage assessments. It was also a record 2.6 miles wide at its largest point. It grew from 1 mile wide to 2.6 miles wide in 30 seconds! What a monster.

May 30th was my last day of chasing as a tour guide for Silver Lining Tours, but thinking Friday was going to be a big day near Oklahoma City, I decided to stick around and chase with some friends. I met up with Peggy Willenberg, Melanie Metz, Kevin Van Leer, and Kate Demchack in El Reno, OK as the first cumulus towers began to develop on the intersection of a stalled front and dryline. The environment was extremely unstable with 4,000+ J/KG of MLCAPE, temperatures in the upper 80s, and dewpoints in the middle 70s. In addition to very steep lapse rates supporting large hail, surface winds were backed out of the south-southeast with 50 kts of effective shear and decent mid and upper level wind speeds, supporting a substantial tornado threat with any supercells that developed within this environment. As a result, the Storm Prediction Center issued a Particularly Dangerous Situation (PDS) Tornado Watch at 3:30 PM CDT.

Initially, there were 3 intense storms that developed on this boundary intersection but these congealed somewhat, which made me think that maybe this day was not going to turn out to be a big tornado day after all, especially since the few days before did not work out as planned. We first went west on I-40, then north on Hwy 270 towards the northern storm with 60k foot echo tops. At this point to the north of Calumet, we could see all 3 storm bases as the storms were intensifying and starting to produce a few lowerings. When the storms started to congeal, we decided to head east on 248th St NW towards Okarche, and then get ahead of all of the storms on the northwest to southeast angled road of Hwy 3 towards Yukon. I did contemplate turning around and heading back south on Hwy 81 to intercept the tail end storm, which was starting to look the best, but this decision not to do this turned out to be a very good one. We went south on Hwy 4 in Yukon and then Hwy 92 south of I-40 as the southern storm became tornado warned. Already traffic was starting to get bad as we were caught in some rush hour congestion and we slowed to a crawl as we attempted get south. I noticed an option to head west, directly at the developing hook echo, on some gravel roads so I took it. This ended up working out perfectly as there was little to no traffic and open roads for us to work with as we approached the storm. We ended up stopping near the intersection near Reuter Rd and Evans Rd, roughly 3 miles from the approaching tornado that we could see was rain-wrapped but visible, along with a satellite tornado that you can see in the video to the right side of the main tornado. I had enough time to take some photos and video, but clearly this was not a storm to mess with as it was getting larger by the minute and moving right towards us. I decided to bail south on S Evans Rd and east on SW 15th St to watch the ever growing and intense wedge tornado pass by. This is when the tornado unexpectedly quickly grew and made a sharp shift to the north towards I-40 and unfortunately injured and killed several chasers in the process. As I recorded the tornado on my camera, I walked away for 30 seconds, came back and the whole tornado to my amazement had exceeded the viewing pane. It was incredible to see a tornado grow that large in that short of time. It was hard to get real excited about this strong and massive tornado, knowing there were probably people and homes in its path, especially since it was approaching Yukon.

After leaving this tornado, we paralleled the storm to the east on SW 15th St into the south part of Yukon, seeing power flashes occur to my northeast along the way. This is when the traffic started to really become a problem. I attempted to bail south and get out of the way of the second and third couplets that were on storms approaching from the west and taking a dive to the southeast. I became stuck in bumper to bumper traffic trying to get across one of the few routes across the Canadian River (S Mustang RD to Hwy 4) in Southwest Oklahoma City. This is when a couplet on radar passed just behind me and my car was slammed by roughly 50 mph RFD winds and people really started freaking out. It was mass chaos as people started abandoning their cars and running for any shelter that they could. There were vehicles slamming into other vehicles, people getting rear-ended, and a total loss of laws and rules that you would see more in a movie rather than playing out in front of you in real life. I witnessed several accidents and people just kept driving, leaving others stranded with disabled vehicles. After that debacle, they police started opening up all lanes across the river and south and not allowing traffic to go back north so we got out of there and over to Tuttle on Hwy 37 and then south on Hwy 93 before the next and stronger couplet on the third storm reached the area. I can honestly say that this is the first time that I thought about leaving my vehicle to find shelter from a tornado as we were not sure if we could beat the third couplet due to the horrendous traffic and almost tried getting into a church. It was the first time that I thought I was trapped in a bad situation with a tornado and no place to go…definitely a scary ordeal. We made it around the storms to the west and then back north on Hwy 81 where we drove through a lot of flash flooding and a large damage path between Union City and El Reno. Here is where there were overturned cars, some thrown well into fields away from any roads, and police and ambulance lights as far as you could see to the east. It was a very eery scene to a scary and deadly day.

MAY 30TH OKLAHOMA - DRYLINE SUPERCELLS & MASSIVE BEAST AT SUNSET

June 30, 2013 by Brad in 2013

Lowering on the left, underneath the developing supercell near Blanchard, OK.

Rising, twisting tail cloud into the developing wall cloud on the storm near Blanchard, OK.

Another shot of the rising scud into the developing wall cloud. Storm starting to get cylindrical base to it.

This got really interesting at this point of the storm. Lots of rotation noted as the storm pulled in moisture-rich low level air.

Still an interesting lowering on the storm and well defined inflow bands as we approached Dibble, OK.

Nice look to the storm near Dibble, OK. At one point, it looked like a little funnel-looking thing underneath, but could not confirm.

Near Lindsay, tornado warned supercell was nearing full maturity.

Storm taking on a liberty bell shape, but looks to be starting to gust out at this time.

Tight, little, but intense updraft near the Red River in southern OK.

Massive beast of a storm approaching sunset near Pauls' Valley, OK.

Looking underneath the shelf of the outflow dominant HP supercell near Paul's Valley, OK.

STORM REPORTS:

STORM PREDICTION CENTER OUTLOOKS:

MAY 30, 2013 CHASE LOG: OKLAHOMA

Written by Rich Hamel (http://www.bostonstormchaser.com/)

This was the last day of Silver Lining’s Prime Time Tour. Another moderate risk day and, since it was Day 10 and we were already at the host hotel, we were able to leave our stuff at the hotel and just bring our chase gear with us. Being in our target area already, were able to loiter around Oklahoma City for a lot of the morning and early afternoon as we knew the storms would initiate relatively close to the city, starting to the north near Enid and then building south roughly along I-44 towards Lawton along the dryline. After lunch and more waiting, the first storms fired and we headed southwest on I-44 as Tornado Watch was issued at 12:55 PM CDT. We were immediately posed with a choice between a more northern storm up near El Reno that looked better on radar, and a younger storm to the south coming up towards Chickasha that was in what appeared to be in the area with the better shear profile. The issue with the northern storms, we feared, was that they would become linear pretty early, merging with an MCS that was already active in Kansas. This did turn out to be true, though the tail end storm hung together longer than we expected, and much later that evening produced a tornado far to the east in Broken Arrow near Tulsa. We stopped at the rest area near Chickasha for a while trying to decide, and then, with the Chickasha storm clearly visible with a broad base and long inflow band to our south, we decided to go after that one, quickly getting through Chickasha and towards Anadarko on Rt. 62. Almost immediately the storm generated a solid wall cloud with rotation as we watched it move by to our northwest, but it never seemed to generate enough focus at the lower-levels, a common theme for the day.

We followed the storm northwest on Rt. 277 towards Blanchard, and it looked like it was ready to tornado at one more point as we stopped for a while east of Dibble (while the locals got ready to head into their storm shelters), but it again never quite got the focused rotation needed to tornado, and we were soon drawn south on Rt. 59 through Lindsay towards the next storm, as there were now a number of isolated supercells to our southwest in a line all the way down to the Red River. After dropping south on Rt. 76, we were soon retracing our route from the Moore tornado day and heading west through Bray to just east of Marlow, where we intercepted another storm with huge hail and rapid rotation that was turning hard right and coming right towards us! We stopped several times, staying just ahead of the core, and eventually ran south on the exact same road we’d seen the brief tornado on east of Bray on the Moore day. We stayed out in front of this storm, which had morphed into a high-precipitation hail storm with baseball-sized hail reported, all the way down to Tatums, where we again stopped and watched the big, teal glowing core pass us to the north, all the while looking to two more supercells, that were alternately being tornado warned, down towards the Red River to the south. Another theme of the day was constantly being torn between storms: From one radar scan to the next we’d be drawn towards a different storm, and every time we left one, it would seem to briefly cycle back up and tempt us to turn right back around.

Again the pattern repeated and after heading south through Fox then east on Rt. 53, we jumped on I-35 and headed south towards Marietta near the Texas border to intercept the last two storms in the line that were right along the Red River. Heading west out of Marietta, we stopped near Falconhead, OK and watched a textbook LP supercell just to our north, with almost perfect LP storm structure. It was clearly shriveling up not long after we arrived though, and we decided to head back north towards the hotel to intercept another big storm up there along I-35 on the way. First, however, as we headed east, the last supercell in line came across the river, and even though it looked to be dying, it was still tornado warned so we turned around and headed through the core just west of Falconhead, getting heavy rain and wind but only the smallest amount of hail. We turned around and headed back to I-35 to a pretty funny sight: what was left of that storm by the time we got on the highway was just the littlest poof of an updraft attached to what could be barely described as a tiny little anvil on top.

Heading back north, we were faced with a huge HP supercell coming across the highway. The structure as we neared the storm at dusk was amazing, mostly because it was just so incredibly big! The base of the storm seemed to stretch on for miles, with a giant rear flank inflow band to the left and a huge cow-killer shelf cloud in front. With structure that good, we had to stop briefly south of Davis, then were able to split between two big cores as we crossed under the storm near Paul’s Valley. Finally, after a dinner stop in Purcell (Braum’s!) we headed back to the hotel, completing the tour.

Lots of storms on this day, but the low-level shear just didn’t get it done. I don’t think I’ve ever chased so many tornado warned storms on the same day without any of them even managing so much as a decent funnel cloud! There were virtually no tornadoes in the moderate threat area for the day, while far to the north where nobody would have expected and nobody was chasing there were a number of them up in Nebraska.

MAY 28TH KANSAS - THE BENNINGTON EF4 TORNADO

June 29, 2013 by Brad in 2013

Supercell storm beginning to get its act together near Bennington, KS. Inflow bands becoming more defined in all directions.

First funnel forms at 5:31 PM CDT as we watch a couple miles to the east.

After the funnel, a lowering forms underneath the updraft as inflow into the storm strengthens, indicating increasing tornado potential.

Moisture rich inflow air being sucked right into the action area underneath the storm updraft as wall cloud forms.

The tornado first forms at 5:47 PM CDT.

Tornado getting larger with inflow surging in from right to left.

Thick cone tornado underneath rapidly rotating mesocylone. Tornado has barely moved.

Well defined and strong stovepipe tornado at this point. Condensation surging up the left side of the tornado.

Zoomed out view showing the incredible storm structure and the stovepipe tornado.

Another shot of the tornado at 5:54 PM CDT.

Tornado becomes rain-wrapped at 6:02 PM CDT.

Tornado getting back out of the rain at 6:03 PM CDT.

What an awesome storm and tornado! Tornado and storm has not moved hardly at all while we have been watching.

Wedge tornado!

Another shot of the wedge tornado with heavy core to the left and inflow tail to the right.

Transitioning to a big high precipitation (HP) supercell as the tornado becomes rain-wrapped.

Tornado finally ended after nearly an hour! New wall cloud forming while an attempt to produce another tornado ensues.

Incredible structure to this supercell with long, striated inflow bands around the mesocyclone and wall cloud underneath.

Massive hook echo on the storm while we sit directly east of the notch. Our location is plotted as the white circle with a dot in the middle. We sat in the same spot the entire life cycle of the tornado and afterwards as the entire storm and tornado hardly even moved!

Velocity couplet showing the tornadic circulation relative to your position as plotted by the white circle and dot.

STORM REPORTS:

STORM PREDICTION CENTER OUTLOOKS:

MAY 28, 2013 CHASE LOG: KANSAS

Written by Rich Hamel (http://www.bostonstormchaser.com/)

A great chase day and one of the shortest ever driven for a chase! The toughest part of this day was figuring out our target. We started the day in Salina, sleeping in a little and waking to discover that we had 3 distinct targets to consider: Northeast Kansas just east of where we were, along the boundary with a good combination of shear and moisture, a nice high plains setup in Northeast Colorado, or the southwest part of the boundary near Dodge City. We agonized for a bit and told the guests we’d meet an hour later, then decided that at least we would not take the Cheyenne Ridge bait and hedge more about where on the boundary to play, so we waited, then went to lunch, hung out at Walmart, then parked at the Petro on the north side of town to wait some more, as by now we’d decided to play the northeast target. Problem was, it looked like we’d waited too long with a cell already dropping a tornado in the Manhattan, KS area, 100 miles east of us and out of range! However, we calmed down and reasoned that if we could get a cell to develop and right turn into the same environment that the Manhattan storm developed in, it should do the same thing. Plus there was a nice triple point setting up just to the west of Salina as boundaries became more established by the afternoon.

We continued to wait as towers bubbled all around us and more and more chasers parked and chatted with us, until finally an updraft just to our west took off and we headed out north on old Highway 81 after it. The storm was not moving fast at all, and we were easily able to get east of it, parking on Rt. 18 just west of Bennington, KS. As we watched, the storm, which was really a group of updrafts, began to congeal into one and showed immediate signs of rotation, much as the Manhattan storm had earlier. We kept our fingers crossed as a cell to the south merged with it, and the cell survived and was soon a rotating monster! The rotation under the mesocyclone continued to increase until, 35 minutes after we initially parked, a long elephant trunk funnel formed, making it 2/3 of the way to the ground before dissipating a minute or two later with a neat ropeout. By now, the wall cloud was spinning like crazy and it was only a matter of time before it tornadoed, and 15 minutes later the storm dropped a big cone about 3 miles west of us and slowly coming directly at us. As it got closer, you could get a good feel for how violent the tornado really was, and soon Bennington was sounding their tornado sirens. As the tornado closed on us, it spawned a brief satellite tornado to its south and occasionally got wrapped in rain. Soon the tornado turned into a monster ½ mile wide wedge that was rotating around a nearly stationary mesocyclone of the storm. What a moose! The structure and slow motion of the storm was incredible, with a striated updraft and inflow bands streaming in from all directions and wrapping around the updraft.

As we sat still in our original spot now for the 2nd hour, something I’d never seen before happened: The storm began to retrograde and soon the storm and the tornado were moving west away from us! At this point the whole tornado was rain-wrapped from our vantage, but the motion of the cloud base and inflow told us it was still in there. Finally it seemed to wind down and the storm went into obvious HP mode, dumping well over 6 inches of water on the same area as where the tornado ground away. Worried about the flash flood warning, we finally left the area about 2.5 hours later, having never moved once after we stopped!

A fantastic chase day virtually right on top of us. In fact, I measured and from the Petro parking lot to where we watched the storm unfold was only 10.4 miles! Incredible! We headed to Logan’s for a nice steak dinner, then to the hotel in Wichita for the night.

MAY 27TH KANSAS - SEVERE STORMS, ALMOST A TORNADO

June 29, 2013 by Brad in 2013

Severe storm just getting going near Kensington, KS. Nice flat base and strong vertical updraft.

Strong inflow into the storm from left to right. Intense rain and hail core in the center of the image underneath the updraft.

Rotation noted with this lowering and an attempt to produce a tornado here. Just could not get it done, but it had that "look" to it.

Broad, circular mesocylcone underneath the storm base with rain/hail core middle.

Storm starting to become HP near Smith Center, KS. Solid core to the right. Nice cylindrical shape to the base of the storm.

Caught a bolt at the end of the chase on another storm near Ellsworth, KS.

STORM REPORTS:

STORM PREDICTION CENTER OUTLOOKS:

MAY 27, 2013 CHASE LOG: KANSAS

Written by Rich Hamel (http://www.bostonstormchaser.com/)

This was a promising chase day with an extremely easy forecast: surface low in western Kansas, sagging cold front along the Kansas/Nebraska border, and dryline equaled triple point play in north-central Kansas. Because the forecast was so easy though, it meant that ALL the chasers would be there, and this turned out to be true. We left North Platte then headed east on I-80 then south down Rt. 183, crossing into Kansas then stopping for lunch in Stockton, KS. Since the atmosphere was not yet ready for initiation, we found a nice park and hung out there for an hour or two waiting for things to get going. There were storms happening in eastern Colorado, and some suggestion that the only place the cap was going to break was on the dry line near Hutchison, but we still felt that the area we were in could be the “sweet spot” for the day. We considered heading down to I-70 to make it easier to play all 3 options but then storms started firing to our north after finally breaking the cap.

While the storm to our north was strengthening rapidly, it was already moving north towards the frontal boundary, and we knew that if the cell crossed into the cold air it wouldn’t last long. Luckily, additional cells were firing down the flank of the first storm south, so all we needed was for one of the tail end storms to turn right and stay south of the front rather than crossing it. We got our wish north of Phillipsburg, and soon were off onto the dirt roads to the east of Rt. 183.

The southern-most storm on our line immediately took over the show and turned straight east right towards us, showing rotation on radar and soon developing a big hook echo. The hook echo was clearly visible with low level stratus being ingested into the storm and the long hook extending from our right to the northeast all the way around and coming back towards us from the southwest. The storm looked like it was getting ready to tornado but it was also still expanding south, and soon, rain and hail was falling around us and threatened to swamp us on the roads if they became muddy, so we bolted east then south on dirt roads north of Kensington to get away, while still keeping in contact with the hook echo region of the storm. We kept proceeding east and south on dirt roads just ahead of the hook, trying to keep out of the rain and stopping every time the storm tried to spin up. At one point, north of Smith Center, there was a notable dust swirl that persisted for a minute or two that was reported as a tornado, but we’re not sure so we won’t count it. Heading towards Esbon the storm looked ready to tornado several times and at one point generated what looked to be a “scud stovepipe” that might have tricked some people, but it wasn’t rotating. Unfortunately, just to the east of that location the storm WAS generating what looked to be a truncated cone tornado based on pictures another chaser showed us, but that area was obscured from our vision by trees. At Esbon we hit pavement and, because we have 2-wheel drive 12 passenger vans, we had to head south to get off the dirt before we got stuck. Those with 4-wheel drive who headed north into the notch ended up seeing a wedge tornado buried in there! With the storm looking more and more HP and additional cells firing to the south, we broke off the northern storm and headed down the line. Even though the severe indices for the environment we were going into were off the charts, the storms died one after another as we passed one core near Beloit, another near Lincoln, and then finally the last two near I-70 and Ellsworth. By the time we’d finished a gas break in Ellsworth, the show was completely over and we headed to Salina for the evening.

MAY 26TH NEBRASKA - STORM STRUCTURE OF THE YEAR!

June 28, 2013 by Brad in 2013

Supercell exploding while train runs for cover near Berwyn, NE.

Intense, explosive updrafts on the storm near Ansley, NE. The right updraft eventually took over.

Underneath the storm updraft as it starts to get a more defined look to it.

Terrific structure of the LP storm as we approached Arcadia, NE.

Another shot of the storm a short time later.

Twisting, LP updraft getting tipped over as storm becomes more surface based near Arcadia, NE.

Incredible storm with lightning bolt right down through the right side of the updraft. One of the best shots I have ever taken!

Caught another bolt!

One more bolt as it got dark and we ended the chase for the evening near Ord, NE.

STORM REPORTS:

STORM PREDICTION CENTER OUTLOOKS:

MAY 26, 2013 CHASE LOG: NEBRASKA

Written by Rich Hamel (http://www.bostonstormchaser.com/)

A day with multiple levels of frustration was followed by great reward: We awoke in Spearfish, SD with the intention of chasing in Montana or northeast Wyoming, but a look at the morning models quickly changed our focus to the southern target in central Nebraska. Both targets had issues: The MT/WY target had better shear, but looked to lack the necessary instability to support anything other than high-based storms, even up there in the higher terrain. In NE, the instability and moisture was there to support strong tornadic storms, but the question was whether the shear profile would get it done. The models thought it would, and we needed to be in KS the following day regardless, so we adjusted our target to Thedford, NE, but left very late as we’d initially expected only a 2 hour drive to our target and not the 4-5 hours it would take to get to Thedford.

As we headed east on I-90 in the soup north of the warm front, it seemed like we’d never get south before initiation as there was already a developing cumulus field in west Cherry County and a mesoscale discussion was issued. However, as we headed south begging for the cap to hold on until we got down there, the cumulus field more or less died and as we emerged into the sun south of Valentine, NE. When we crossed the frontal boundary, the whole area looked capped to the point where we wondered whether initiation would happen at all. We reached Thedford at about 5:30pm with no sign of anything happening and waited for over an hour before finally towers exploded to our north and east and we were off and running. Between Dunning and Anselmo on Rt. 2, we were faced with a tough decision: The updraft we were targeting to our west was the oldest, but despite the strong convection and broad updraft, it didn’t seem to be doing much, while a younger updraft to the north quickly generated an overshooting top and cloud heights above 50 thousand feet. We continued past Broken Bow trying to decide whether to break off and head north up Rt. 183 to intercept the northern storm, but as we got near Westerville and up along the side of the updraft the structure was incredible! We could not possibly bail on the storm, regardless of what was going on with a tank of an updraft just to our north, so we headed east through the north edge of the hail core and stopped to film the big barrel base with laminar striations on the bottom and a crisp spiraling updraft above. In fact, the structure was so good that we didn’t hesitate getting out to film it despite the golf ball sized hailstones that were falling all around us!

Soon the updraft was literally right on top of us and anvil lightning began striking behind us, so it was time to get out of dodge and back in front to continue to watch the storm develop. We passed through Arcadia and stopped again with a more distant view of the magnificently structured supercell, then again moved on towards Ord, still keeping our options open towards heading towards the north storm. Since initiation had been so late however, we decided that even if we did break off and head north we’d never get to the northern storm before dark. When our storm became tornado warned, we decided to focus on it and headed west on dirt roads trying to get a closer look at the base. The road network killed us though, passing through wooded areas and down into valleys that frustrated us over and over, so we popped back out on Rt. 70 and headed west back towards Arcadia, then stopped and watched the unbelievably structured storm, backlit against the setting sun and throwing cloud to cloud and cloud to ground lightning prolifically. The storm by now had a rear inflow band that seemed to extend southwest all the way to the horizon and was just a textbook-diagram looking storm.

After spending 30 minutes or so filming the awesome lightning display, we again headed towards Ord to possibly get a look into the notch of our storm, or possibly take a look at the now massive HP storm the northern cell had become. Our cell died though, and as we got to Ord we gave up and headed for our hotel in North Platte. On the way back we were treated to an excellent lightning show from the northern cell that was rapidly plunging south and back building. What a great storm from a day that looked like it was going to be a failure several times!

MAY 25TH SOUTH DAKOTA - AWESOME STORM STRUCTURE!

June 27, 2013 by Brad in 2013

Feeder bands into the developing storm coming off the Black Hills near Sturgis.

Storm starting to get more of rounded and lower base as it comes off the Black Hills east of Sturgis.

Storm dumping a rain and hail core onto Bear Butte Recreation Area.

Storm developing into a supercell at this time with massive hail core near Bear Butte Recreation Area.

Had to get a picture in front of this thing. I love chasing in South Dakota! Always photogenic in this area.

Lowering inside the right edge of the rain/hail core with low scud being pulled in at the time. Starting to take mothership appearance.

Beautiful storm over the open country of South Dakota.

Incredible structure with this storm to the east of Rapid City, SD.

Big, blocky wall cloud forming underneath the base of the storm. No rotation noted at the time.

A different storm but similar, great structure.

Awesome mothership, LP supercell to the east of Rapid City, SD.

Storm really starting to get that twisting, corkscrew updraft look to it.

LP supercell morphing into a large, rotating soda can.

Definitely looks like a spinning mothership at this point!

Incredible LP updraft backlit by sunset near Wasta, SD at the end of the day!

STORM REPORTS:

STORM PREDICTION CENTER OUTLOOKS:

MAY 25, 2013 CHASE LOG: SOUTH DAKOTA

Written by Rich Hamel (http://www.bostonstormchaser.com/)

Structure was the name of the game today as we left North Platte, NE with our target being northeast of Rapid City, SD. We headed up through Valentine and then into South Dakota. By the time we reached I-90, storms were already firing off the Black Hills, and we made the decision to head north, then west to get to our target storm. We stopped in Philip, SD for fuel then the chase was on! At Howes, we turned west as our storm, which was between Belle Fourche and Spearfish, had barely moved in the hour we had approached it, and then it began to right turn hard over Bear Butte.

One thing about chasing in South Dakota is that the terrain is spectacular even without a storm over it, which makes for some very photogenic shots. As we drove towards Union Center on Rt. 34 we stopped and watched the storm about 20 miles from us, framed over Bear Butte with a farm and a river in the foreground, and a long inflow band wrapping around over us into the storm. After about 15 minutes we headed west towards Sturgis, then dropped south onto dirt roads and drove right up to the hook area of the storm as it belched a big hail core right over the butte. The storm still barely moved and we were able to maneuver to just about any position we wanted for a good view, and at every stop we were not disappointed at the structure of the storm. Behind us, the inflow winds were howling into the storms for hours. After the first cell started to cycle down after a weak attempt to spin up, the western updraft of the storm took over and again, we drove right into the notch and watched the incredibly structured supercell spinning away with a big, broad meso as it came right to us, with dirt entrained in the inflow blasting by us towards the updraft. Luckily the dirt roads were in good shape and we didn’t have much trouble getting around in the road hole. As the second cell got very close to us it dropped a HUGE hail core just to our northwest where you could almost watch the individual streams of hail falling. Again, there was solid rotation on radar but still, not even a decent attempt at a funnel.

After that big hail core bombed out, the new western updraft took over and we did the same thing all over again as the new storm took on the classic “mothership” look with a big disk of a base and striated layers on top. We had to run east towards Elm Springs to beat the big hail, then headed south with the storm obediently following along. The structure somehow was even better than the previous two updrafts! Finally, we decided to get out ahead of the storm for a distant view of the structure, getting on I-90 again and heading a little east to a rest area near Wasta. As the sun set behind the storm, the storm got even MORE photogenic! As it crossed the highway, a decent funnel formed (finally) but then the storm cycled down. We found another great vantage point and watched the storm, which was now becoming a skinny LP storm, twisting and turning with the sun setting behind it and numerous cloud to ground and cloud to cloud bolts coming out of the vault area. We finally called it quits and headed to the hotel in Spearfish for the night.

MAY 24TH COLORADO & NEBRASKA - LP STORM & TORNADO WARNED SUPERCELL

June 11, 2013 by Brad in 2013

Storms beginning to fire near Holyoke, CO. Nice base and updraft on the left.

Mothership base of storm in the foreground and another storm base in the background.

Really nice LP storm near Lamar, NE. Storm kept popping cg's and had shear funnels the whole time we sat watching.

View of the base of the left storm as it approached us near Lamar, NE. Beautiful, backlit LP!

Lowering on the storm near Grant, NE.

One of my favorite shots I have ever taken. Incredible mammatus and storm near Grant, NE near sunset.

Lightning illuminating the storm near Elsie, NE.

Another shot of the storm being lit up by lightning near Elsie, NE.

Caught a bolt!

Another bolt from the right and a nice view of the storm structure.

STORM REPORTS:

STORM PREDICTION CENTER OUTLOOKS:

MAY 24, 2013 CHASE LOG: COLORADO & NEBRASKA

Written by Rich Hamel (http://www.bostonstormchaser.com/)

Starting the day off in Amarillo, Texas, we had 3 distinct chase targets for the day, one in northeast Colorado/southwest Nebraska, a “Campo”-style play near Lamar, Colorado, and a lesser play up in the Nebraska Panhandle near Sydney. As we headed north, we were faced with a puzzle as the models were in complete disagreement regarding where the best storms were going to be: While most pointed toward the area between Wray, CO, and Imperial, NE, the HRRR broke out a huge supercell down near Lamar and had virtually nothing in northeast Colorado. We decided to hedge our bets but lean towards the north because the conditions all pointed that way, and as we lunched in Burlington, CO the winds there were veered and the dew points dropping rapidly as the dry line approached, so we decided to head north to Wray. The transit through southeastern Colorado was amazing: I’ve never seen it so dry down there and as a result, it seemed that there was blowing dirt from horizon to horizon throughout the whole region and Sheridan Lake was completely dried up, with the lakebed adding to the blowing dirt.

In Wray, we were posed with the same problem as earlier: Storms were underway and looking decent to our south, but up north where our target area was, the towers that were forming kept withering and dying. Still, our attention was drawn by the Holyoke, CO surface observation that suggested dewpoints in the low 60’s streaming into the area. Finally after a long wait, two updrafts finally managed to get established and we raced up north in between the two of them. Once we got to Holyoke we were right in between the two cells, but they weren’t looking great, with the left split being a tiny little LP Supercell spinning away but very high based, while the right split kept pulsing up and down. Meanwhile, there were solid cells to the north and south that alternately looked good then lousy from scan to scan on radar. We decided to head east on Route 6 as that would allow us to keep contact with the western cell but also be in position to move to any of the others near us, as one thing that did work to our favor was that all of the storms were moving very slowly.

Crossing into Nebraska, we stopped near Lamar (Nebraska, not Colorado) and observed the Western storm as it seemed to be getting better organized. This was a continuous theme for the next 6 hours: every time we tried to leave the storm, it showed us just a little something that made us stick with it, despite different cells around us pulsing up and down and enticing us towards them. Near Lamar the storm showed a nice rain-free updraft and was popping cloud to ground lightning bolts continuously. We also saw several shear funnels on the storm, one of which persisted for at least 3 or 4 minutes before it fizzled out. As the storm didn’t appear to be intensifying while others around it did, we headed east, then north, bypassing Imperial. As we headed into Grant we got pounded by golfball hail from the front flank core of our storm, then as we popped out north of the core near Grant we were gifted with a tremendous mammatus display on the backshear of the anvil from the cell to our north, a cell which was showing rotation on radar. But again, as we drove away from it our cell pulsed back up and showed rotation of its own. At this point it had the classic “backwards C” looking updraft and clear rotation. After numerous brief stops to watch our storm, we headed east as it started to get dark and, as the low-level jet kicked up the storm really took off. Just at dusk the storm gave us a fantastic lightning show near Elsie, then as we continued east the storm was tornado warned and showed strong rotation on radar. We noted a lowering under the mesocyclone in the distance, but could never see anything touch down. We proceeded south of Wallace to get out of the rain and parked and watched as the area of rotation came right to us. The inflow winds were pouring into the storm past us, and as they blew through the wires overhead it created a spooky howling sound that added to the atmosphere. After about 20 minutes the hook echo was almost right on top of us and we had to run to the southeast to get out of the way. We found a place to watch it pass and observed a large blocky wall cloud through the rain on the back side of the hook as it passed by, but again no tornado.

Finally, the rotating area was well past us and there were no roads that would allow us to keep up, so we headed north behind the rear flank of the storm with a great cloud to cloud lightning display just to our east and all kinds of tree debris from hail on the road. We thought we’d see some big hailstones as we headed through the tree debris and hail fog, but never spotted any. Not long after that the storm collided with a left-mover to its south and collapsed so we called it a night and made the easy 40 mile trip to our hotel in North Platte, though that did mean driving through the northern part of the collapsing core, which was a bit of a challenge.

MAY 23RD TEXAS PANHANDLE - DIRTY SUPERCELL STORM

June 10, 2013 by Brad in 2013

Rear flank downdraft coming around hook echo region of supercell to the southeast of Floydada, TX.

Another shot of the dirt being blown around the hook echo region of the supercell.

Lots of dirt being blown around and a lot of motion/rotation occurring on the tornado warned storm southeast of Floydada, TX.

A couple of elongated inflow tails into the base of the storm. Main core of supercell to the right.

Another structure shot just to the right of the photo taken above.

Looking directly at the hook and the forward flank downdraft. Interesting area of rotation was occurring just above and to the right of the road. Could have been a funnel attempting to form but shielded by a lot of blowing dirt.

A shot of the base and inflow on the southeast side of the supercell to the north of Crosbyton, TX.

Wall cloud forming north of Crosbyton, TX as storm is tornado warned.

View to the right of the image above, looking at the east and southeast facing sides of the storm.

STORM REPORTS:

STORM PREDICTION CENTER OUTLOOKS:

MAY 23, 2013 CHASE LOG: TEXAS

This turned out to be a fun chase day full of Texas storms and dirt. We started the day in Amarillo after eating at the Big Texan restaurant the night before, so our bellies were full of steak! Model guidance, especially the HRRR, was indicating two plays, one with supercells developing from a Lubbock to Childress line and then a second wave of storms near Amarillo later in the day. The set-up included a weak surface low to the west of Amarillo with a trailing dryline due south along I-27 and an outflow boundary from a morning MCS draped southeast of the surface low through northwest TX. Temperatures were heating up into the lower 90s in the warm sector south of the outflow boundary and ahead of the dryline, while dewpoints were mixing out into the middle 60s. The concern was the larger temp/dewpoint spreads that would result in high-based storms initially and lower tornado potential. However, steep lapse rates, large CAPE, and sufficient deep layer shear existed for supercells and a threat for very large hail, as well as tornadoes as LCL heights lowered.

Our general target was the Matador area, and the plan was to proceed to Tulia and then decide whether to head east toward Turkey or further south and then east towards Matador. Before we made Tulia however, the first storm of the day fired north of Floydada as a tornado watch was issued at 1:40 PM CDT. This storm appeared firmly anchored to the boundary, barely moving, and there were already reports of possible landspout tornadoes before we could get a visual of the storm base. With the storm not moving there was no point in going east, so we proceeded south to Plainville, then on to Floydada to intercept. It was apparent as we got on the storm that it was going to be a dirty mess! There was dirt flying around all over the place and we saw several gustnadoes as we passed south of the hook echo of the storm and stopped in perfect position to see if a tornado would develop. This was one of those situations that you could look at the radar image of a storm then look up and really see all of the features laid out in front of you. To our north the inflow was streaming into the storm right to left, but just west of us where the hook wrapped around the meso was spinning left to right. The storm looked like it would tighten up and produce just to our northwest several times, but could never get it done.

The front flank core began approaching us as it wrapped around the hook and the storm was showing large hail on radar so it was time to bail, get south, and into position for the next attempt. We went south past Dougherty on farm roads, watching the storm cycling while pushing a huge plume of dirt out in front of it to our west, eventually stopping near Crosbyton. The storm by now had broken away from the boundary and was heading south, and after one last try to produce a wall cloud, became a dirty, outflow dominant mess. We stopped in Ralls for a break, and then headed north to get ready for round two up near Amarillo. By the time we’d reached Floydada again, the show was already beginning north and we bee-lined it to I-27 to head back to Amarillo, all the while getting buffeted by outflow winds from our original storm to our east. The storms to the north developed quickly and we could see a big overshoot over the updraft of our target storm. The storm merged with another cell as it developed, which bought us some time, then split, which bought us more and soon we were close enough to get ready to chase it. The atmosphere had become pretty mixed by that time though, and the storms didn’t recover from the split as expected. In fact, the right split died almost immediately! We chased the left split, which was now traveling to the northeast north of Amarillo, for a bit but that storm also collapsed quickly and we called it a night, conveniently within ½ an hour of the hotel. Overall it was a fun chase day with a great supercell that almost produced a tornado.

MAY 20TH OKLAHOMA & TEXAS - SUPERCELL THUNDERSTORMS

June 10, 2013 by Brad in 2013

Towering cumulus as storms begin firing to the south of Chickasha, OK.

The right updraft is the beginning of the storm that spawned the Moore, OK EF-5 tornado.

Tornado in the distance near Bray, OK. Another wall cloud in the foreground from closer storm.

Wall cloud on the storm near Pernell, OK.

Hail and rain core embedded in the hook echo of the tornado warned storm west of Nocona, TX.

Another shot of the rain and hail core getting closer to us just before we left the area.

Storm approaching us near Muenster, TX.

Storm starting to gust out and form a shelf cloud near Muenster, TX

Beautiful mammatus at sunset.

Tour guests enjoying the view of the storm and taking pictures towards the end of the day's chase.

In the Bear's Cage of the Nocona storm as it was tornado warned.

STORM REPORTS:

STORM PREDICTION CENTER OUTLOOKS:

MAY 20, 2013 CHASE LOG: OKLAHOMA & TEXAS

I flew into Oklahoma City on this morning after working for a week in Greenville, SC, anticipating chasing right out of the gate. Even though this was the arrival day for the gusts of Silver Lining Tours, there were some guests that flew in early and others that stayed a day late to chase with Roger Hill and the gang, so we ended up with a full group. The previous day produced big tornadoes through central OK and southern KS and this day’s set-up was not much different as expectations were high for another big tornado day. The set-up included a stationary front draped through central OK to a surface low and triple point just west of the OKC Metro and a dryline to the south. Low level winds were veered a bit at the surface but moisture and instability were more than sufficient for supercells and tornadoes. Winds became more backed at the surface by the late afternoon and there was also 50-60 kts of Effective Bulk Shear entering the region by that time. A Tornado Watch was issued at 1:10 PM CDT for all of central and eastern OK.

As the first towers started going up during the early afternoon, we progressed southwest on I-44 towards Chickasha. One storm had already caught our interest and was looking the best just east of Lawton. As we neared Chickasha, I noticed the storms starting to get going just to our north that would be approaching Oklahoma City. Even though the storms developing here were going up in a good environment and on a triple point, the decision was made not to follow due to the likelihood of these storms going into a major urban area. We decided to head on Hwy 19 to Lindsey and then south on Hwy 76 towards the southern storm near Duncan and moving east. The northern storm that we blew off after seeing go up was the storm that produced the deadly EF-5 Moore tornado.

We intercepted the Duncan storm in the vicinity of Velma as it became tornado warned. There was also a western updraft that was starting to take over the show. The storm we were on to the east had a nice lowering and eventually a wall cloud, but the western storm was the one to be on as it produced a tornado several miles to our west, which we could barely see in the distance. It was a nice tapered cone and we could see it rope out in the distance as our wall cloud closest to us failed to do anything. After both storms weakened, we progressed south of the Red River where a large HP (high precipitation) storm was moving due east along Hwy 82 in far northern TX. We intercepted this storm near Nocona as sunset was approaching. This storm initially had some good structure and we got right into the notch as the storm was tornado warned and had a nice hook echo on radar. The hook was wrapping in and we did not notice a wall cloud at that time, although a brief tornado was reported before we got there. We got out of there before the large hail started falling and called it a night as the storm became even more HP and started to spit out a gust front.

2012 STORM CHASING HIGHLIGHTS VIDEO

October 24, 2012 by Brad in 2012

This is my 2012 storm chasing highlights video! Even though it was a slow severe weather year, I was able to get out and see some incredible storms, 7 tornadoes, and plenty of other weather phenomenon. Picking the right times and days to chase was an important part of chasing in 2012. Some of the highlights include a tornado near Oxford, Nebraska on April 14th, a May 1st tornado in Minnesota and a nice supercell and funnel the following day, the incredible La Crosse, Kansas tornadoes on May 25th, the Piedmont supercell and tornado on May 29th, some incredible storm structure with nearly every chase at the end of May, and then a week of active weather in June that produced some nice shelf clouds in Minnesota.

JULY 6TH, 2012 MINNESOTA - WALL CLOUD ON SEVERE STORM

July 09, 2012 by Brad in 2012

07-06-2012: MINNESOTA This day featured a Slight Risk, stretching from eastern SD through central MN into northern WI. There was a 5% tornado risk along a stalled front through central MN, roughly from Benson to North Branch, MN. The setup included this front that actually sagged south to near the Hwy 12 corridor by the afternoon and then southwest towards Marshall to a surface low across southeast SD by the afternoon. In the upper levels, there was generally weak support over central/southern MN as the higher bulk shear and jet level winds were displaced well to the north of the boundary across northern MN into Ontario. A weak shortwave was expected to give a glancing blow to the area along the front and ignite severe thunderstorms across the area by mid to late afternoon.

I left work at 2:30pm and met Wes Hyduke at my place and we chose to head northwest towards the Dassel area to target initiation. As we headed west towards Dassel, we noticed a CU field growing directly ahead of us where two boundaries appeared to be coming together. Between 3:45 and 4:45pm, this CU field grew in size and became better defined as the boundary began to move southeast towards the Twin Cities. We progressed southeast through Winsted and New Germany, following what was becoming towering CU in an environment characterized by 3000-4000 j/kg of MLCAPE and rich boundary layer moisture of low 70s dewpoints. Storms were having a difficult time getting going due to the capped air of 21-24C 850 temps and 12-14C 700 mb temps. However, one storm broke through around 6pm near Fairfax, right as a mesoscale discussion was issued that highlighted the risk for severe thunderstorms with damaging winds and large hail in central MN. Between 6-7pm, additional storms fired on the boundary over the Twin Cities and northeast, while we chose to target the southwest storm approaching New Auburn. We ended up traveling south on Cty Rd 33/5 to near the Assumption State Wildlife Management Area where we intercepted the storm. At 6:40pm, a Severe Thunderstorm Watch was issued for areas from south-central MN through the Twin Cities and into northwest WI.

The storm became better organized northeast of Green Isle and was one of the few storms that did not yet get undercut by the southeast moving front. All storms north of the boundary that were not rooted were quickly weakening and dying, but our storm was still locked on the boundary. In the vicinity of 7:15-7:30pm, the storm did produce a slowly rotating wall cloud and what looked to be a brief funnel as the boundary came through and quickly undercut the storm. It was surprising that it did this much because the surface winds were very weak and sometimes non-existent, but the storm seemed to have some sort of lower mid-level inflow as noted by the condensating inflow tail. The wall cloud did not last long and the storm had pretty good structure for only a short while before completely dying upon moving north of the boundary.

A pair of severe warned storms along the front to our northeast, over the Twin Cities metro.

Lowering on a storm to our northwest near Hamburg, MN.

Beautiful storm with wall cloud underneath and inflow tail cloud into it. New updraft on the southwest flank.

Closer view of the wall cloud and inflow tail with rain core on the north side.

Towards the tail end of where I think there may have been a short-lived funnel on the left side of the wall cloud. This feature is shown better in the video.

Watching the backlit storm as it began meeting its demise east of Green Isle, MN.

STORM REPORTS:

STORM PREDICTION CENTER OUTLOOKS:

JUNE 14TH, 2012 MINNESOTA - SEVERE STORMS & SHELF CLOUDS

June 22, 2012 by Brad in 2012

06-14-2012: MINNESOTA This was a tricky day but, initially, with a lot of promise. SPC had outlined a Slight Risk through much of MN with a 10% tornado risk from roughly Faribault through the Twin Cities and north to Hinckley. A complex of storms had rolled through the Twin Cities during the morning hours, producing a magnificent shelf cloud that I was able to view and take pictures of from my home in Burnsville. After the shelf went through, Jeff Buck and I went south on I-35 to get out ahead of the storm. We progressed to Faribault as the gust front and outflow boundary began to stall and the shelf fell apart right in front of our eyes, so we turned around and headed back home. The thinking was that this outflow boundary would lift back north to the Twin Cities during the afternoon and we would be in good position at my house.

There was a surface low developing in far northeast SD with a cold front draped south of there. The western part of the outflow boundary/warm front began to lift back north during the afternoon with the low, but persistent convection along the rest of the boundary allowed it to remain stalled through roughly Mankato over to just north of Rochester. This convection ended up being the caveat that limited the overall severe weather risk and essentially shut down any chance for tornadoes. We left my place and progressed down Hwy 169 and west on Hwy 19 to near Gaylord where we stopped to re-evaluate. A mesoscale discussion was issued by the SPC at 1:44pm for areas along and ahead of the surface low/cold front and near the western portion of the outflow boundary where the environment had become moderately unstable with 1500-2000 j/kg of MLCAPE and bulk shear of 40-55 kts. At 2:45pm, a severe thunderstorm watch was issued for counties right near and north of the outflow boundary, where storms were ongoing but becoming stronger as the instability increased and temperatures cooled aloft into the afternoon hours.

The first storm we intercepted was just south of Gaylord on Hwy 22. This storm initially looked pretty good with an inflow tail and intense rain/hail core with echo tops over 40,000 ft. But this cell could never really get going and we ended up bailing and chasing after stronger storms to the east on Cty Hwy 8, then south on Hwy 112 out of Le Sueur and east on Hwy 99. These storms appeared to be going into a worse environment, but continued to strengthen after we stayed put northwest of Faribault. The storms looked really strong, almost supercell-like, on radar as they progressed over Hwy 52 and towards the MS River. These storms dropped considerable amounts of rainfall through the day that led to widespread flooding through this entire area as well as some hail and wind damage.

After waiting around for 20 min, a new cell began to form and we went back west, viewing a shelf cloud moving over Mazaska Lake (picture below), and even an attempt at a base on a storm near the Hwy 99/Cty Rd 137 intersection. The storm that produced the base eventually puked out so we went back west to intercept another storm near Hwy 169 in St Peter. After taking a pit stop at the local dairy queen, we made a feeble attempt to chase back east on Hwy 99 all the way to I-35 to see if we could muster up anything else, but nothing all that interesting developing along the way so we headed back home. Overall, I think the clouds and persistent convection really kept things in check and weaker than anticipated on this day, and dewpoints never really got as high as forecast once again. I’m sure there were more reasons, but these were the glaring issues.

Awesome shelf cloud moving over my house in Burnsville, MN around 9am.

Shelf cloud from across the street in the Byerly's parking lot.

Strong core underneath developing storm southwest of Gaylord, MN.

Shelf cloud moving across Mazaska Lake northwest of Faribault, MN.

A weak attempt at a lowering, the only one of the day, southeast of Montgomery, MN on Hwy 99.

Tried to punch this core heading north towards Montgomery, but it only had dime size at most when we went through.

Rather intense shelf cloud with rapid rising motion on the forward flank near Le Center, MN.

STORM REPORTS:

SPC OUTLOOK:

SPC TORNADO OUTLOOK (1630z):

JUNE 10TH, 2012 MINNESOTA - SHELF CLOUDS GALORE

June 22, 2012 by Brad in 2012

06-10-2012: MINNESOTA A short chase log here as this was not a significant severe weather day, but did have some photogenic opportunities. I had to work this morning and took off right after work to chase with MaryLynn across central MN. There was a slight risk for most of MN with a 5% tornado risk. This was a cold front setup for the area, which usually means one thing for storm mode…linear storms with wind damage and shelf clouds. That is exactly what we got as we progressed northwest on Hwy 10 and then north on Hwy 25 through Foley and north from there to get out ahead of initially more isolated storms developing well out ahead of the cold front and more linear storms further west. These storms were developing in a marginally unstable environment with dewpoints only in the lower 60s, so they had a tough time getting going and even holding together. We decided to let those storms go to the north and chase west on 153rd St and Hwy 27 through Pierz to intercept the severe warned line of storms approaching Little Falls. After getting through Little Falls and south on Hwy 10, that is where we saw our first shelf cloud of the day as the line moved in. We were able to stay just ahead of the storms as we moved southeast on Hwy 10, due to the orientation of the line, while we attempted to intercept the most intense part of the storm southwest of Royalton on the Great River Road. At this point, we were slammed by some estimated 40 mph winds, small hail, and intense rainfall rates. There must have been higher winds to the south, as we encountered a bunch of trees down on the road as we approached Sartell from the north on Hwy 1. We were able to get around the trees and get back through Sartell on Hwy 10 and eventually back onto I-94 to get ahead of the line once again. We stopped in Monticello just off the exit to take more pictures of the shelf cloud and then traveled back home for the night to Burnsville, where we ended up getting hit by another intense storm right at sunset. This storm apparently produced a tornado near Belle Plaine at 8:15pm, but was embedded in the storm when it looked like it was producing straight line winds.

Shelf cloud approaching us near Little Falls, MN.

Well structured shelf cloud getting closer south of Little Falls, MN.

Another shot of the cool looking shelf.

Looking to the north as the shelf was moving over.

Interesting feature here near Royalton, MN. This looked like a storm base with a notch in the line, shear markers on GR3, and some rotation shown on the velocity imagery at the time. It rocketed by us to the north fairly quickly and looked to gust out a short time later.

Tail cloud on the storm base as we crossed the MS River near Royalton, looking north.

Shelf cloud approaching Monticello, MN.

Shelf cloud about to overtake us in Monticello, MN.

STORM REPORTS:

SPC OUTLOOK:

MAY 30TH, 2012 TEXAS - MASSIVE HIGH PRECIPITATION SUPERCELL

June 22, 2012 by Brad in 2012

05-30-2012 CHASE LOG: TEXAS This ended up being a very good day with some forecasting challenges. We were presented with a dilemma in the morning, being torn between a target that SPC and many other chasers favored along the warm front in southern KS into northern OK, with the other target along the dryline in the eastern TX Panhandle. We favored the TX Panhandle target due to the presence of higher instability and with the moisture axis being oriented right over the area, along with a dryline in place. The better upper level support was to the north, but there was still around 50 kts of deep layer shear and very steep lapse rates in this area. The concern was that, if rich moisture could reach the warm front, storm motion would be right along the boundary and lead to a tornado threat. It became apparent as we left Oklahoma City and headed west on I-40 that the moisture was not going to be as high as the models suggested further north. We officially made up our minds towards early afternoon to head to TX as the short range model guidance was breaking out a pair of supercells in the Panhandle and we thought the better environment was in place. We headed towards the dryline, east of the Caprock, towards Memphis, TX.

At 2:58pm, a mesoscale discussion was issued by SPC for an area of northwest TX in our target zone. This discussion highlighted the corridor of strong instability, as noted by the 2500-3500 j/kg of MLCAPE up through the area, with surface dewpoints in the mid 60s, and steep lapse rates near 8.0 C/km. This also noted the wave clouds that we noticed upon driving to our target area, suggesting the environment would be more stable further to the east. Shortly after 4pm, supercells exploded on the dryline near and east of the Caprock in the eastern TX Panhandle, while a Tornado Watch was issued for the area at 3:40pm. We were on our first storm near Memphis, which had a large rain-free updraft initially and a pair of long inflow bands feeding into the storm. We were able to sit and watch this storm for a half hour before the lightning threat became too great and we were forced to bail south on Hwy 287 towards Childress. We had to watch a storm to our south that had unimpeded inflow and was in danger of cutting off the inflow into our storm. However, our storm continued to look good as it produced numerous shear funnels and awesome corkscrew structure with strong inflow sucking in red dirt right into the updraft base. The inflow had to be around 50 mph INTO the storm at times as we progressed into Estelline and decided to head west around the mesocyclone on Hwy 86. We watched as this storm neared, but quickly turned back and almost got cut off by huge hail, some that started to fall as we neared Estelline and bailed south again on Hwy 287. This was where we put a few more cracks in the windshields due to the hard golf ball or larger sized hail that was falling. We got out ahead of the storm again and watched as it became a skinnier LP storm, but was tornado warned and did have some rotation in the base at times. A short while later it looked to be weakening, but still had great structure as we stopped by Cee Vee, TX to watch. The southern storm was taking over and intensifying.

We blasted south towards Paducah to get to the southern storm that was growing to be a massive HP monster with gorilla sized hail. This storm had significant rotation with 100 kts of shear, and soon became tornado warned as we tried to get ahead. As we headed down Rt. 83 with the rear flank of the storm's hook echo just about 10 miles to our southeast, we observed significant lightning-induced fires on both side of the road. Heading into Paducah it was an eerie sight: There was a giant plume of red dirt suspended in the air just east of town, and the town itself had clearly suffered some significant wind damage, with limbs broken off trees, sheet metal roofing blown off buildings, and debris all over the place. One spotter report suggested 100 mph rear-flank downdraft winds or a potential landspout tornado has caused the damage. Sure enough, as we exited the town, a long ropey landspout tornado with a red debris fan was visible on the rear flank of the storm and remained for a minute or two before it dissipated. That was tornado number 5 for the tour! Having cleared Paducah, we were still cutoff from the inflow notch of the storm and were forced to continue another town south, down to Guthrie. While we could still not see into the inflow notch of the storm, the mammatus clouds hanging out of the anvil were absolutely spectacular. As we continued east through Knox City and west of Seymour, we finally got out ahead of the massive supercell where it had terrific structure due to the spiraled, stacked plates look. I honestly cannot remember seeing such a huge supercell storm in my life. It was a storm that was dropping hail larger than softballs, had confirmed, rain-wrapped tornadoes buried in it, and high amounts of cg lightning. Certainly not something we wanted to wait around for and roll over us. We did observe the storm towards sunset as we traveled towards Seymour and a fantastic lightning display upon driving home for the night towards Oklahoma City, just as the gust front from the KS storms reached the city.

Storm just getting going as it moved off the Caprock and dryline near Memphis, TX.

LP supercell south of Memphis, TX with shear funnel on the right side of the storm near the clear slot.

Very strong inflow at our back and into the storm, sucking in all of the red Texas dirt right into the updraft base.

Storm taking on better structure north of Estelline, TX.

Another view of the updraft curling up into the storm north of Estelline, TX.

Supercell starting to get tipped over with more rain/hail falling out of the eastern end of the updraft.

Massive supercell as we started to get out ahead near Benjamin, TX.

Huge HP supercell nearing us east of Benjamin, TX.

Video capture of a lightning bolt out of the supercell between Benjamin and Seymour, TX.

STORM REPORTS:

SPC OUTLOOKS:

MAY 29TH, 2012 OKLAHOMA - SUPERCELL STRUCTURE & PIEDMONT TORNADO

June 16, 2012 by Brad in 2012

05-29-2012: OKLAHOMA I never thought that I would have a chase day where I would see a tornado, but this would be overshadowed by the supercell structure itself. This was certainly one of those days! Our group of SLT crew and guests started out in Wichita Falls, TX and headed north, targeting an area between Woodward and Enid, OK. SPC had a Slight Risk out from southern KS through much of OK and into northern TX with a 5% tornado risk (all outlooks below). The setup by the afternoon included a 1007 mb surface low near Childress, TX with a moisture axis extending northward through western OK where dewpoints were in the upper 60s. Strong instability developed ahead of surface low with 3,000-4,500 j/kg of MLCAPE building into much of OK. In the upper levels, there was northwest flow at 500 mb with a weak area of vorticity caught in the flow that would help be the trigger for convection. 0-6 km shear of 35-45 kts with strong directional shear from 1-4 km indicated an environment favorable for supercells and an isolated tornado threat, while steep mid level lapse rates would bring a risk for very large hail.

We progressed north to Watonga, OK on Hwy 281, sat for a while to watch the developing cumulus field, and then decided to head further north on Hwy 51A to Fairview. Along the way, SPC issued a Mesoscale Discussion at 3:06pm for the area and a Severe Thunderstorm Watch at 3:55pm, valid until 11:00pm for most of western OK. The cumulus quickly turned into towers going up from near the KS border to northwest TX and one developing storm soon caught our eye near Isabella. This initial storm was struggling at first to get going and remained very LP as we got closer to Okeene, but took on incredible structure as the storm base and updraft were twisting like a corkscrew and took on a barber pole look. At this point near Okeene, we continued to remain on the southeast part of the storm, which allowed for great structure shots, but the storm started firing cg’s like crazy and we were forced into the vans. The lightning even caused numerous fires in the dry wheat fields in the area! Upon reaching a point near Hennessey, the storm began taking on more classic supercell characteristics and was spinning like a top, while a rotating wall cloud formed under the base. I thought for sure that this storm would drop a tornado here, but it never could get its balance down right.

We drove towards Kingfisher on Hwy 81 and waited on a hill on the south part of town as the supercell began taking on more of an HP look and barreled towards the town. The supercell had several mesocyclones and a few wall clouds as it moved near and over Kingfisher…kind of a scary moment where it looked like it might drop one on the town. We were in danger of being cut off from this storm as we continued south to Okarche and then east towards Piedmont, stopping a few times along the way to take pictures of the amazing storm structure. The storm took on striations with a tentacle look to the inflow bands as they wrapped completely around the storm’s mesocyclone, while a bowl shaped lowering formed as we stopped and watched near Piedmont. This was the third time in the day that I thought I may have seen the best supercell structure in my life! As a left-moving storm came up from the south, the gust front interacted with our storm and this was enough to produce a tornado at 8:28pm, which lasted for a few minutes. The tornado itself was kind of hard to see due to being rain-wrapped, but it was certainly there and reported by several other chasers. Right after producing the tornado, the storm really began to gust out and become a squall line as several storms congealed. We raced to the south out ahead and west on I-40 towards El Reno and south on Hwy 81. Near the Canadian River we saw a huge dust plume that looked to be RFD or strong outflow kicking around/ahead of the west side of the developing squall line, and this was (falsely) reported as a tornado at that time. However, it did look interesting between the lightning flashes as it was becoming dark and even we questioned if it could be a tornado for a brief moment. After getting ahead of the squall line and seeing the shelf cloud, we punched back north through the rain, wind, and small hail to get back to our hotel in Oklahoma City for the night. It was interesting when we got back, as this area had been pounded by high winds and baseball sized hail with the storms we were chasing all day. There was quite a bit of noticeable damage to vehicles, signs, and trees as a result, as well as some good stories from the hotel staff and guest.

Cumulus above grain elevator in Watonga, OK.

Twisting and intense updraft with low precipitation supercell near Okeene, OK.

Shear funnel on supercell near Okeene, OK.

Low precipitation supercell becoming more intense with larger base between Okeene and Hennessey, OK.

Storm becoming even better structured with striations and intense updraft near Hennessey, OK. Possibly a funnel on the right side of the base?

Incredibly structured, striated and intense supercell near Hennessey, OK. One of the best I have ever seen!

Supercell getting more of that "wall cloud" look under the base.

Almost produced a tornado at this point. Rapid condensation and some rotation with this lowering as it was coming right at us.

In front of the storm as it was close to producing.

More of a classic supercell with lots of rotation and motion in this base over Kingfisher, OK.

One of the best supercells that I have ever seen! This was near Piedmont, OK shortly before producing the tornado. Notice the inflow "tentacle" wrapping around the base of the storm, intense rain/hail core, and lowered bowl in the middle, indicating a tornado is close to forming.

Another view of the amazing supercell a short while later as the inflow band was wrapping around. Still have that bowl lowering underneath.

Left edge of supercell showing the thick, stacked plates look.

Rain wrapped tornado near Piedmont, OK. If you look close, you can see the debris fan.

Closer view of the tornado from the previous photo.

Rain wrapped tornado in the middle as it was close to lifting near Piedmont, OK.

Storm Reports:

SPC Outlooks:

MAY 28TH, 2012 TEXAS - TEXAS SIZE STORMS

June 08, 2012 by Brad in 2012

05-28-12: TEXAS We started the day in Salina, KS and progressed towards northwest TX where SPC had a Slight Risk for severe weather in place with a 30% hatched area for significant hail. With dewpoints in the lower 60s, better upper level forcing well to the north, and fairly weak southeast surface winds, we figured that storms would be fairly high based and that this was going to be mainly a structure type of day with damaging winds and big hail the main severe threats. As mentioned, higher jet level winds on this day were well to the north as a trough had established itself near MO/MS Valley regions, and there was ~55 kts at 250 mb as well as 30-40 kts at 500 mb nosing into the area by 00Z. A slow moving cold front was the trigger for supercell development as an area of low pressure moved northeast along the boundary towards Crowell, TX by late afternoon.

Our route took us from Oklahoma City southwest through Wichita Falls, TX and on Hwy 277 towards Seymour, TX. At 2:54pm, SPC issued a Mesoscale Discussion for northwest TX into OK along the boundary. This discussion noted the moderate to strong instability as 2500-3000 j/kg of MLCAPE was present along and south of the boundary with little to no cap left and towering cumulus taking place. There was also 30-40 kts of deep layer shear present and lapse rates around 8C/km, favorable for supercells to produce very large hail. A severe thunderstorm watch soon followed at 3:50pm for the area as storms began to fire along the boundary.

Our storm we first targeted was northwest of Seymour towards Crowell as this storm was right ahead of the low and looked the healthiest on radar. We progressed up FTM 1919 where we ran into a number of other chasers surrounding this storm in the middle of nowhere. It was a good feeling to be out there and experiencing the storm away from towns and out in the open. Upon reaching the storm, we watched as it dumped several enormous hail cores and likely a wet microburst or two. We were able to sit and photograph this storm for a good half hour, getting some good cloud-to-ground lightning and structure shots, until the storm kicked out a big RFD plume and started to speed up/catch up to us. As we headed back towards Seymour, the VIL’s were maxed out with GRLevel3 projecting 4” hail! Definitely something we didn’t want to mess with. At that time the storm to the east was looking better with a well defined lowering, while our storm was turning into a massive HP hail machine. We progressed southeast on Hwy 114 towards Olney to stay between the two storms and give us options but, as we did, everything began to consolidate into a linear mess and eventually an intense bowing line picking up speed towards us. In order to get out of the way, we charged west towards Throckmorton but quickly realized we would not beat the massive hail core to town, so we headed south on FTM 578 to buy some more time. Near Woodson, the structure of the storm was awesome with a green/orange glow and an impressive sharks teeth shelf cloud. Realizing we were never going to beat this storm, we tucked the vans up against a shed in Woodson to get some protection from the hail/wind. We expected to be bombarded with hail, but instead got none at all as the core barely missed us. There were torrential downpours and high winds with some very close CG lightning that hit a church steeple twice, which was only ¼ mile away.

The core of the storm passed over and we went to leave, but the middle van became stuck in the mud and Van 3 almost got stuck as well! With the help of the great volunteer fire department of Woodson, the van was pulled out of the mud and we were on our way back to Wichita Falls for the night, while viewing an incredible backlit storm at sunset as the line had moved off to our southeast.

Supercell beginning to develop on the triple point southeast of Crowell, TX.

Supercell developing rapidly with two well focused hail cores and great storm structure.

Large rain and hail core as the storm becomes more intense, producing numerous cloud to ground lightning strikes.

Closer view of the lightning strike in the previous photo.

Another strike as the storm draws closer.

Interesting base forming on the supercell between Crowell and Seymour, TX. Massive hail core behind the base. Strong inflow was occurring into the storm at this time.

The gang from Silver Lining Tours documenting the storm.

This is the only time we saw rotation in the base of the storm in its feeble attempt to produce a wall cloud at the front. Condensating, cold outflow scud occurring on the right side of the image as the hail core approaches.

Shelf cloud on the monstrous HP supercell to the north of Woodson, TX.

Storm Reports:

SPC Outlooks:

MAY 27TH, 2012 KANSAS - SUPERCELL STRUCTURE

June 06, 2012 by Brad in 2012

05-27-2012: KANSAS The upper trough was emerging into the Plains on this day, so there was quite a bit of hype and potential for intense severe weather and a tornado threat. SPC had issued a Moderate Risk, extending from north-central KS to MN, primarily for expected damaging winds and very large hail due to the steep mid level lapse rates and cold air aloft. However, mid and upper level winds, and consequently bulk shear, were not as favorable as much of the upper level support remained well to the north and seemed a bit out of phase for tornadoes and intense supercell storms. Still, we did get some nice storms.

The set-up by the afternoon included an area of low pressure in northwest KS near the town of Norton, with a stalling frontal boundary to the northeast through eastern NE, and a dryline extending south of the low through central KS. We chose to target the northern end of the dryline, putting us into position to play the triple point/front to the north, or the tail end dryline storms to the south. Our route consisted of driving from North Platte, NE to Holdredge, NE for lunch and eventually setting up in Franklin, NE awaiting initiation. A mesoscale discussion came out at 2:58pm from eastern NE to southwest MN, while another mesoscale discussion came out at 3:10pm targeting our area along the dryline into KS and OK. A severe thunderstorm watch soon followed for areas to the north, while another severe box was issued for KS and OK at 3:55pm. Storms began initiating on the northern boundary at 4pm, but took until after 5pm to initiate further south along the dryline. These storms were in an environment characterized by MLCAPE of 2000-2500 j/kg with Effective Shear of 30-35 kts, but expected to increase into the evening.

We first intercepted a storm near Smith Center, KS. Waiting right in its path, it kicked up strong outflow filled with dirt and, shortly after, started throwing golf ball sized hail at us! A couple hail stones near tennis ball size fell and we quickly turned the vehicles to face the storm so we would not break the side windows. After the storm passed over, we followed to the north, noting an intense hail core opening up on the storm to our west. Our storm soon weakened, so we dropped to the south to near Kensington, KS to take a closer look at the monstrous, white hail core with the storm to our west. This core was so big and well defined, it actually looked like a massive tornado and I believe there was a false report of one at that time. We watched this storm for a while as it did not change much, and left it to target the tail end storms firing along the dryline. As we got on these storms, each one moved off the dryline and weakened considerably. It was a strange pattern with each storm that did this as we kept dropping south to target the tail end storms. Although having great structure, each storm would croak upon moving off the dryline.

Our storm of the day moved up towards I-70 at us as we progressed east of Hays, KS towards Russell. This storm intensified near and after sunset, giving us a bout of hail and an incredible lightning display as we continued to stay ahead of it on the Interstate. It eventually took on more of an LP look to it with great structure as it was lit up by the lightning bolts at dark. We stopped a few times along our route to Salina to take pictures of this storm before eventually heading to the hotel for the night.

Intense hail core on the storm near Alton, KS.

Nicely structured supercell with core behind the base.

Inflow into the storm with broad base, I believe near Stockton, KS.

Supercell to our south, developing near La Crosse, KS.

Another shot of the storm to our south near sunset.

Our storm near Stockton, KS becoming LP and weakening upon moving off the dryline.

Mothership supercell lit up by lightning with the SLT tour vans in the foreground near Russell, KS.

One of my favorite shots I have ever taken. Storm lit up by lightning as we called it a night in a remote Kansas field.

Storm Reports:

SPC Outlooks:

May 25th, 2012 KANSAS - THE LACROSSE TORNADO

June 06, 2012 by Brad in 2012

05-25-2012 CHASE LOG: KANSAS What an incredible day! Going into it, this day had potential to produce tornadic supercells but the one caveat was the cap and if storms would break through. There was an area of low pressure over the OK Panhandle with a warm front draped through central KS with a dryline extending southward through west-central KS and a triple point in the vicinity of Ness City, KS. The warm front further east across northeast KS and northwest MO appeared to be the safer play, with a riskier chance for supercells along the dryline where the cap was stronger. We progressed south from Kearney, NE on Hwy 183 through Hays, KS and set up shop in a park in La Crosse, KS where the triple point was just to our west. We favored the dryline over the warm front as most of the guidance was breaking the cap and any storms that did form in this environment would encounter extreme instability and high amounts of wind shear for rotating updrafts, supercells, and tornadoes. Moisture was a bit better further to the east, but only by a couple degrees as upper 60s dewpoints advected north along the dryline into this area. In the upper levels, about 40-50 kts of southwest 500 mb flow was in place as a trough was developing in the western U.S.

As we waited near the Barb Wire Museum in La Crosse, cumulus began building on the triple point, but kept getting tipped over, hit the cap, and died. A mesoscale discussion was issued at 3:57pm from SPC for our area, highlighting the risk for supercells with damaging winds and large hail as well as a tightly focused tornado threat. Finally one storm broke the cap and kaboom! Right away this storm had an amazing base and incredible structure with both forward and rear inflow bands into the storm as we blasted north towards Liebenthal to get ahead of the storm. As we progressed east on a road near Victoria, KS and on the northern end of the storm, the RFD winds really started to kick in hard with a plume of dust and dirt being pulled completely around the lowered base of the storm and right back into the updraft. Shortly after, what looked like either a gustnado or tornado formed underneath the developing wall cloud and a tornado was reported from what you can see in the photos below. This was a bit questionable as it may have been a tightly focused gustnado, but there is a bit of a nub underneath the wall cloud and I guess you could call it a tornado since it was right underneath the area where you would expect one. If it was, it was weak as we ended up driving right through the dust/dirt plume from this RFD surge and “tornado”. We followed this storm to near Russell before giving up on it was it eventually died. Around this time, at 6:50pm, a tornado watch was issued for the area.

Our attention then turned towards the tail end storm and we calculated that we could get there before dark by taking Hwy 281 south and Hwy 4 back to La Crosse to intercept. On the way, the middle storm produced a very well defined wall cloud and we actually did turn around after reaching La Crosse after hearing that this storm was producing. However, as we did so, our tail end storm west of La Crosse started to look better and we turned back around to head back towards our cell around sunset. Approaching the storm from the east, we could see the well defined inflow bands into it. Shortly after, about 5-6 miles west of La Crosse, this storm produced a rapidly rotating wall cloud and strong condensation and rising motion on the right edge. This storm took a while to do it (about 20 minutes with the wall cloud), but finally produced a slow moving cone tornado at 9:20pm that progressed across Hwy 4 west of La Crosse, became a large stovepipe and elephant trunk 1-2 miles northwest of the town, and eventually a tall rope tornado 2-3 miles northeast of town as the sirens blared the whole time and we got a close up view. It was tough to take pictures and video of this tornado due to the low light, but we managed due to the nearly constant lightning that was illuminating the tornado the entire time. The nice thing was that we were able to adjust camera settings and take our time since this tornado was on the ground for 54 minutes and only traveled around 10 mph! After the tornado roped out, we saw another tornado form to the northeast of La Crosse. We made the decision to head west behind the storm to get out of the way, but we could not go north due to downed powerlines and poles, so we continued to head west out of La Crosse, eventually back to our hotel much further north in North Platte, NE. An interesting bit of news that we found out later was that a satellite tornado had formed to the south of the "main" tornado and caused some damage on the southern end of La Crosse. We were on the northern end of town so that would have put us right in between tornadoes at the time!

Interesting start to the day, checking out the barbed wire tornado in the museum in La Crosse, KS. An omen of what we would see later in the day!

Inflow scud foot becoming attached to the base as the storm started to become surface-based north of La Crosse, KS.

RFD surge starting to pick up dirt as the storm forms a wall cloud to the southeast of Hays, KS.

We originally thought that this was a tight gustnado near Victoria, KS, but it was reported as a tornado and was officially listed as one.

Insane RFD surge now picking up dirt and debris, lofting it well up into the air and back into the inflow of the storm southeast of Victoria, KS.

Storm starting to take on that mothership look with huge rotating wall cloud and continued strong, dirty RFD push.

Mammatus clouds near Otis, KS.

Inflow stingers into the rotating wall cloud when we reached the storm west of La Crosse, KS at sunset.

Another shot of the rapidly condensating wall cloud and rotating supercell at sunset.

Tornado forming right after sunset 5-6 miles west of La Crosse, KS.

Tough to see, but you can make out the large cone tornado in there as it crossed Hwy 4 west of La Crosse, KS.

Blurry, but wanted to show the large tornado only 1-2 miles north of La Crosse as it was about to cross Hwy 183. Tornado almost became a wedge as the entire wall cloud was violently rotating at this point.

Another blurry shot of the large tornado about to cross Hwy 183 to the north of La Crosse.

Tornado quickly became a large stovepipe as it crossed Hwy 183. Entire wall cloud eroded.

Tornado transitioning to a large elephant trunk as the cloud base continued to erode. Only 2 miles north of La Crosse.

Another view of the elephant trunk north-northeast of town. Substantial debris fan at this point.

Tornado starting to transition into a roping out phase.

Tornado starting to rope out, estimated at 3 miles north-northeast of La Crosse at this point.

Tornado in full rope-out mode, dissipating a short while later.

Tornado Path:

Radar reflectivity at 9:40pm with the La Crosse storm circled as it was producing a large tornado.

Storm relative velocity at 9:40pm, showing the tight couplet associated with the tornado. Estimated at over 100 kts of shear from this image at the time as inbound and outbound winds are maxed out.

Storm Reports:

SPC Outlooks:

MAY 23rd, 2012 NEBRASKA - GUSTNADO & SUPERCELLS

June 06, 2012 by Brad in 2012

05-23-2012 CHASE LOG: NEBRASKA This was Day 2 of being a guide for Silver Lining Tours. We drove 1,000 miles the day before, from Oklahoma City, OK to near Bowdle, SD to chase a couple of marginally severe thunderstorms, ironically on the same date as the Bowdle wedge tornado in 2010. The set-up this day was pointing at an area around Grand Island, NE or into northwest IA along a cold front that was settling into the region. We left Aberdeen, SD south on Hwy 281 towards Grand Island. As we approached O’Neill, NE, there was some debate on whether the better potential would be across northwest IA or southeast NE. We decided to split the difference and head southeast on Hwy 275 towards Norfolk to buy us some more time. Upon doing so, the new RAP guidance came in and was pointing at the area around Columbus as the place to be, so we headed south on Hwy 81 as storms began to develop on the boundary. These were moving quickly to the east with the front so we progressed east on Hwy 30 toward Fremont. Upon reaching a storm near North Bend, NE, it produced a gustnado right in town and we were able to drive right along-side of it. The closest that I have ever come to a gustnado!

We moved northeast with the storm from Fremont to north of Blair as the storm began to show some signs of rotation. The Missouri River became a problem and we were forced to backtrack and cross the river near Blair. The storm continued to show signs of rotation and was severe warned through the duration, but we determined it was uncatchable into western IA due to our delay crossing the river over to Missouri Valley, IA. Another storm started to take shape to our southwest near Seward, NE so we crossed back over and eventually intercepted the storm near Valley, NE. It was tornado warned for a short duration due to rotation indicated on radar, but did not produce a tornado. What this storm did have was very good structure as the supercell had a large bowl base and actually had a short-lived wall cloud southwest of Valley. After the wall cloud occluded, it formed a terrific tail cloud into the base towards the time it was about to move over us with great horizontal, rolling motion. We got out of there to get a glimpse of what kind of hail this storm was dropping to the north. Near the intersection of Hwy 275 and Hwy 36, we encountered numerous quarter to half dollar size hailstones near the NWS office. Thereafter, we decided to head towards the hotel in Lincoln, but another storm came up at us from the southwest and we went up I-80 to watch a magnificent lightning display before heading back.

Whoa! A double rainbow! Heading east on Hwy 30 near Columbus, NE.

Storm approaching us from the southwest with lowering under base near Valley, NE.

Wall cloud starting to form on the mothership shaped supercell southwest of Valley, NE.

Wall cloud becoming tighter with faster upward motion and condensation. Hail core to the right.

The closest that this storm came to producing a funnel.

Ground dragging inflow tail cloud into the base as the storm started to lose the wall cloud and become outflow dominant.

Storm Reports:

May 3rd, 2012 Iowa Storm Chase - Severe Hail & Wind

May 12, 2012 by Brad in 2012

05-03-2012 CHASE LOG: IOWA I was not expecting much out of this day as it was looking like the weaker severe weather day of the first 3 days of May for the Upper Midwest. However, I had vacation with no obligations and decided to wait at my parents in southern MN for anything to develop along a remnant outflow boundary that had pushed south to near the MN/IA border from morning convection to the north. I thought about leaving in the morning and heading south towards the main synoptic front that had settled in near the IA/MO border, but the tornado threat did not look all that great in my opinion, and I thought my chances for seeing at least severe weather were just as good close to home.

Around 2pm CT, a lone storm first developed near a remnant boundary intersection just to the north of Emmetsburg, IA. I jumped all over this storm, heading south on I-35 and then west on Hwy 9 and then continued west out of Forest City on Cty Rd A42, intercepting the storm near Bancroft. The storm was developing in an environment characterized by MLCAPE values near and exceeding 1000 j/kg and effective bulk shear on the order of 25-30 knots. A subtle shortwave was also noted on water vapor, per the mesoscale discussion issued by SPC at 2:12pm, that likely led to the isolated thunderstorm development. The MD also highlighted that severe hail would be possible, yet isolated enough that a watch may not be needed. A watch was never issued for this event.

Upon reaching the storm, it was apparent that the storms were going to be very slow-moving and easy to keep up with. I proceeded to drive back and forth, in and out of the hail core of this storm on Cty Rd A42 for several hours, mainly experiencing an abundance of dime to nickel sized hail and intense rain/hail rates. Some of the more intense hail I experienced right in the town of Forest City where there were reports of isolated hail near quarter size. The storm picked up speed a bit and, as you can see towards the end of the video below, I encountered some very intense winds from the storm near the intersection of 310th St and Grouse Ave about 4 miles north of Clear Lake. I continued to follow the storm east, moving right along the intense hail core, to near Osage before leaving the storm as it was quickly losing intensity as it moved into more stable air.

One of the few photos I took from the day as I focused more on video. Intense hail core ahead of me after I just crossed I-35 on Cty Rd B20/300th St to the north of Clear Lake, IA.

Storm forming a ragged shelf cloud as it began to weaken to the southwest of Osage, IA.

OUTLOOKS:

REPORTS: