2010 Storm Chasing Highlights Video

February 10, 2011 by Brad in 2010

2010 goes down as the most insane and successful storm chasing year that I have had to date. This video details only a small fraction of the tornado, hail, wind, and extreme weather highlights from some of the more prolific severe weather days in 2010, including April 29th, May 18th, May 19th, May 22nd, May 23rd, May 25th, May 26th, June 1st, June 17th, and July 14th. I began the year by seeing the Washington, KS tornado on April 29th, but the real show came later in May when I was a guide for Silver Lining Tours, a storm chasing tour company. During the 10 days of that trip, we had seen 18 tornadoes...definitely the most amazing stretch of tornado days in my life. The most incredible tornado of the year occurred on May 22nd with the Bowdle Wedge tornado, while the chase day of the year occurred on June 17th with the Minnesota Tornado Outbreak. What an incredible year it was and I am very fortunate to have been able to experience it all. Now on to the 2011 Chase Season!

September 6th, 2010 Storm Chase - Severe Thunderstorm

November 06, 2010 by Brad in 2010

09-06-10 CHASE LOG: IA After flying in from KPIT for work, I had the rest of the day off and thought it would be decent enough set-up to try a relatively local chase. MaryLynn and I left Burnsville around 2:30pm and went south on I-35, targeting somewhere in the Mason City, IA area where I thought the best combination of low/deep layer shear, instability, and moisture would be in place. We ended up reevaluating things at the Albert Lea truck stop and storms started to fire on the cold front to the southwest of the area as a small area of clearing allowed things to destabilize. One, messy storm was near Emmetsburg, IA so we waited around until another, southern storm fired near Fort Dodge and looked a little better, having access to the better environment as well. We intercepted the storm a few miles west of Dows and it really did look decent for a short while with a nice lowering that was in the right spot underneath the updraft (see pics below). After this storm struggled to get its act together, we progressed north to another storm that was starting to look better and saw a messy lowering near Northwood, IA. Not really good enough to post any pictures though.

Nice little chase day, overall, but thought it would turn out at least a little better. All of the cloud cover and elevated showers really held down the instability and the cold front was moving very fast so I think those were some of the main issues. Plus the tight, compact vorticity center was well to the north across central MN. Certainly this system did not lack wind shear!

Storm when we first got on it near Dows, IA with noticeable lowering underneath the vault.

Lowering becoming more well defined and closer to the ground a few miles west of Dows, IA.

Zoomed out view of the lowering underneath the storm.

Beautiful view to our south of another storm near Ames, IA.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157625199922745/

Storm Reports:

July 17th, 2010 Minnesota Storm Chase - Supercell Thunderstorm

July 30, 2010 by Brad in 2010

07-17-10 CHASE LOG: MN A moderate risk for severe weather, issued by the Storm Prediction Center, was in place this day across much of MN. A surface low was forecast to move into northeast SD and extreme west-central MN by late in the day while a warm front was draped to the north of I-94 across north-central MN and a cold front into eastern SD. Peggy Willenberg, MaryLynn, and I left the Twin Cities near 1pm and progressed northwest on I-94, targeting an area just to the west of Elbow Lake, MN near the MN/ND/SD border area. Our initial thoughts were to position ourselves just ahead of the triple point that was expected to be near this area by late afternoon, shortly after initiation. However, Mother Nature threw a wrench into things and a very nice supercell developed on the warm front near Sauk Centre, MN and we were in perfect position to intercept the storm near Melrose around 3pm. This storm was already in a highly sheared and unstable environment and soon got its act together, producing a couple of ragged, rotating wall clouds near Melrose and near Oak Township. The storm was already producing a large mesocyclone to the northeast of the wall clouds and this meso was starting to arc and gust out at this point, with a shelf-like feature on the leading edge.

After getting cored by this storm and getting hit by nickel sized hail near Oak Township, there were other storms that fired ahead of the stronger supercell. At this point, our main storm had weakened with no wall cloud or lowering visible. Based on what was occurring, we thought the storm was traveling into a “slightly” less favorable environment than what was further west-northwest of our position. The environment that this storm was heading into was still favorable overall to sustain itself and produce tornadoes, but was slightly less favorable as the storm progressed southeast towards the Twin Cities. This storm did end up having beautiful structure upon moving towards the northwest Twin Cities metro and a huge, rotating, gusted out meso. There were a couple of tornado reports from this cell, but I am doubting any tornadoes actually occurred as the reports were suspect, no pictures or video of the “tornadoes” were taken, and the damage that occurred was more coincident with straight line wind damage and hail.

After bailing on the storm we traveled up I-94 and then took Hwy 27 west out of Alexandria towards Wheaton. Intense thunderstorms had already developed north of the warm front, near the triple point and along the cold front, with a few of these storms well to our north being tornado and severe warned. New storms began to fire ahead of the initial storms on the triple point and we waited to see what these would do. SB CAPE values at this time were in the 1500-2500 J/kg range with a nose of 3000 J/kg pocking up into southwest MN, while Effective Helicity values were actually in the 300-600 m2/s2 range across this area! This would normally be very supportive of strongly rotating supercells, but it became apparent that the upper trough had arrived at this point, as there were numerous updrafts occurring and the storms were starting to congeal into a big mess with the cloud shield spreading downstream and seeding any new storms that were trying to develop ahead of the forming cluster in SD. We picked a couple of the stronger updrafts and tried to stay ahead, while storms began to go linear by 7pm. There was a nice shelf cloud that we stayed ahead of from Willmar to Delano, where we finally let it overtake us with heavy rain, small hail, and estimated winds up to 45 mph. The storm did bow out through the far northern Twin Cities metro and produce some wind damage through this area after we had ended the chase for the evening.

Turbulent sky approaching the supercell near Albany, MN.

Looking at the approaching beast of a storm near Albany, MN.

Large mesocyclone underneath the supercell near Melrose, MN.

The edge of the mesocyclone and storm base near Melrose, MN.

Rotating wall cloud with rising scud into it near I-94 and exit 131.

A short time later as the wall cloud was starting to become more blocky and still rotating with rising motion.

Very fast rising motion and condensation into the storm base near Meire Grove, MN.

Another wall cloud behind the rain curtain near Grove Township, MN.

Mammatus underneath the anvil near New Munich, MN.

Leading edge of shelf cloud near Litchfield, MN.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157624617679940

Storm Reports:

July 13th, 2010 North Dakota and Minnesota Storm Chase - Slow Moving, Photogenic Supercell

July 17, 2010 by Brad in 2010

07-13-10 CHASE LOG: ND/MN I did not expect to be storm chasing this day as I had things going on. However, I somehow managed to get everything accomplished by 1 PM and left Burnsville with MaryLynn, targeting extreme northeast SD. The setup was an upper trough approaching this area with an area of low pressure across north-central SD and a warm front draped across northeast SD into west-central MN. This was a modest instability and sheared environment with SB CAPE values of 1000-2000 J/KG nosing northward into the eastern Dakotas and lesser instability and wind shear into MN, while a nose of higher instability was noted further west across central SD. An intense complex of thunderstorms developed north of the warm front, first near Bismarck as we left the Twin Cities and continued to evolve, become surface based, and maintain intensity with supercell characteristics as the storms traveled into southeast ND. We traveled to Ortonville, MN and the thinking was that new storms would fire to the south on the warm front in southeast SD, and we would be in perfect position. However, it became clear that this area was going to remain capped as the cumulus became flat with little to no vertical development. Our only chance at anything was to go north on I-29 and make an attempt to intercept the supercells that were slowly moving into southeast ND. The southern end of the thunderstorm clusters had been tornado warned all afternoon and remained warned as we approached from the south on Hwy 18. The storm had yet to produce a tornado and continued to cycle wall clouds as we followed on east on Cty Rd 2, across I-29 and then east on Cty Hwy 30 in MN. Near the ND/MN border near the town of Christine, the storm produced a low, rotating wall cloud and a large funnel for around a minute. This was the storm’s only shot of producing from when we were on the storm. Near the same time, another storm to the north produced a tornado northeast of Fargo, ND. Overall this was a good chase as the storm we were on had beautiful structure and, at times, a terrific “mothership” appearance. It was nice to be able to follow such a slow moving, photogenic supercell through open terrain without many other chasers around. After the cell crossed into MN, it was getting dark, so we bailed on the storm shortly after 9 PM near I-94. This storm later produced an EF-0 tornado near Dent, MN after dark.

Vault region of supercell near Leonard, ND.

Lowered base under rotating mesocyclone region of supercell near Leonard, ND.

Inflow region and structure of supercell near Walcott, ND.

Another shot of the storm structure and Liberty Bell appearance near Walcott, ND.

Funnel cloud forming on the supercell near Christine, ND.

Another shot of the funnel forming on the supercell near Christine, ND.

Funnel cloud on the storm near the ND/MN border.

Awesome view of the supercell and the storm base east of Wolverton, MN.

Base underneath storm and hail core in the background near I-94 south of Barnesville, MN.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157624396366691/

Storm Reports:

Map of 100713_rpts's severe weather reports

July 14th Southeast Minnesota Storm Chase - The Northfield Tornadoes

July 15, 2010 by Brad in 2010

07-14-10 CHASE LOG: MN This was a day that many, as well as myself, were hyping for tornado potential and it did not disappoint. MaryLynn and I, as well as our friend Sheena McLain, left Burnsville around noon and headed down I-35 to Faribault, MN to wait for initiation, which was expected during the early afternoon hours. My thinking was to get south of where I thought storms would initiate and approach from the south where we could get a better view and not have to core punch if storms fired quickly. Convection had been firing all morning over the Twin Cities Metro and these storms appeared to lay out an outflow boundary just south of the metro area. Storms fired before 2 PM to the west of I-35 and one storm in particular took off on the boundary, with an echo top that quickly grew to over 55,000 feet. Our plan was to intercept this storm by taking Hwy 19 west of I-35. Unexpectedly, we ran into some road construction near Lonsdale and the storm almost managed to get away from us before we made it through and around the detour and east on Cty Rd 86.

As we traveled on 86, there was a lowering directly ahead that was trying to organize into a wall cloud. This feature did not manage to get its act together but a different wall cloud soon formed to the south of 86, a few miles northwest of Northfield. The wall cloud quickly started to rotate and form a funnel and at this time I called the report into the NWS as there was not a tornado warning on this storm yet. Soon the tornado warning came out and almost instantly the first funnel descended to near the ground around 2-3 miles north of Northfield. It was short lived and we questioned at the time whether it did touch down, but soon got confirmation of several spotter and chaser reports that it indeed was a tornado. The wall cloud quickly recycled and developed another, and larger, funnel 3-4 miles northeast of Northfield that became an elephant trunk and was easily over ¾ of the way to the ground. This also was a confirmed tornado that damaged some buildings and blew over a semi on Hwy 47. We stopped at the intersection of 86 and Hwy 56 as the tornado lifted but with a continued rapidly rotating funnel to near our location before the feature dissipated.

The tornadic storm soon became cut-off from good inflow air by a storm to its south and east and we decided to bail on Hwy 52 to get south of the line of developing supercells. We core punched a few storms with extremely heavy rain and got south of the developing line. Nothing was really looking all that great at this point but there was a new storm developing near Stewartville, MN that was directly south of our location and would be an easy intercept if we went south on Hwy 52 to I-90 east. We eventually did intercept this storm that was moving at 50+ mph near Lewiston and this is where we saw another wall cloud and a short-lived cone funnel. We followed the storm to Winona and watched it race off into WI. Thereafter, another storm fired to our west so we traveled back west on I-90 to intercept the storm near St Charles. This storm had some interesting features but nothing that looked like it would produce so we decided to start heading home for the night.

As we had dinner in Rochester, new storms fired on the cold front and became severe as we left Rochester to the north on Hwy 52. Upon reaching Oronoco, we could see a very low, ground dragging wall cloud that had formed on a cell near Zumbro Falls! This really was a surprise as I was expecting everything to be linear at this point due to the strong southwest surface winds crossing the cold front, but this storm did appear to get its act together and even had a hook signature on radar. We attempted to follow northeast on Hwy 60 as a funnel cloud was reported on the storm. It quickly went linear as we got close and this is where we FINALLY ended the chase.

Flanking towers going up to the southwest of the developing supercell near Lonsdale, MN.

Rotating wall cloud to the east of I-35, 3 miles northwest of Northfield, MN.

Funnel cloud near the time of the first tornado touchdown 2-3 miles north of Northfield, MN.

Stovepipe tornado ~3 miles north-northeast of Northfield, MN (confirmed touchdown).

Tornado roping out 3-4 miles northeast of Northfield, MN.

Rapidly rotating funnel cloud near Randolph, MN.

New updraft going up on cell near Dover, MN.

Wall cloud and funnel on cell near Lewiston, MN.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157624383030539/

Radar showing hook echo near time of the tornadoes.

Radar velocity image at the time of one of the tornadoes (from NWS Twin Cities). Notice the couplet of inbound and outbound winds to the north of Northfield.

Storm Reports:

June 17th Minnesota Tornadoes Case Study

June 27, 2010 by Brad in 2010

On June 17th, 2010 a powerful storm system progressed across the Northern Plains and Upper Midwest, leading to an outbreak of severe weather and strong tornadoes across North Dakota and Minnesota. The damage resulting from the tornadoes, extreme wind, and large hail was catastrophic for several farming communities, particularly across north-central and far southern Minnesota. So far, there have been 20 tornadoes confirmed by the National Weather Service with 3 of these tornadoes of EF4 strength in Minnesota (1 in North Dakota) and 4 other tornadoes of EF3 intensity in Minnesota. Wind speeds with these tornadoes would have been in the 166-200 mph range for EF4 tornadoes and 136-165 mph range for EF3 intensity. All of these tornadoes occurred between 4-8 pm. This tornado outbreak was the most for the area since July 6th, 1999, when 17 tornadoes in North Dakotas and 3 in Minnesota, with an F4 tornado in Mountain, North Dakota.

Here is the link to my chase log if you are interested: http://eyeonthetwister.com/index.php/2010/06/0617/

To put this event into perspective, here are some facts that the National Weather Service - Twin Cities were kindly able to post on their site:

• The three EF4 tornadoes in Minnesota were the first EF4 or stronger tornado since the Granite Falls Tornado of July 25th, 2000.

• It was the most number of EF4 tornadoes or greater since Black Sunday, April 30th, 1967.

• The four total EF-4 tornadoes in Minnesota and North Dakota were the most in any one event across the country since the "Super Tuesday" Outbreak on Feb 5-6, 2008.

• The number of fatalities due to tornadoes in Minnesota was the highest since July 5, 1978 (4).

They synoptic set-up consisted of an upper level trough that had moved from the Pacific Northwest the day before to the northern High Plains by the morning of the 17th (Fig a). Upper level ridging was sliding towards the Great Lakes with upper level height falls across the Upper Midwest in response to the upper trough.

Fig (a): Analyzed 500 mb plot from 12Z on the morning of June 17.

The 700 mb analysis (Fig b) shows a strong shortwave through western South Dakota into central Nebraska with very moist conditions ahead of the wave and significant drying in its wake. 700 mb temperatures of 10-12 deg C were analyzed as far north as south-central North Dakota at this time with warm advection ongoing, indicating that a strong cap was going to be in place as warmer air continued to be funneled north ahead of the shortwave. However, strong forcing was able to overcome the cap during the early afternoon.

Fig (b): Analyzed 700 mb plot from 12Z on the morning of June 17.

There are some things to take away from the morning observed sounding from OAX (Fig c), which was likely the most indicative of the inflow sounding into the Minnesota storms. First is the ML CAPE that is already at 3372 J/kg and already an unstable airmass if updrafts were able to break through the warm air aloft near 800 mb. Another is significant drying in the mid levels of the atmosphere, which would allow for dry air entrainment into any storms, more efficient latent heat release and, consequently, more explosive updraft/downdraft combinations with any storms that could develop (this is very noticeable later on water vapor). In the wind fields, strong low level turning and increase in the winds is evident by the sounding and hodograph, leading to 0-1 km and 0-3 km SRH values of 386 and 395, respectively. This environment is already highly sheared and unstable during the early morning, making for a Supercell Composite of 1.

Fig (c): The observed morning upper air sounding from OAX (Omaha, NE).

At the surface the morning of June 17th (shown in Fig d), I have analyzed a low pressure system across northwest South Dakota that has started to occlude along the South Dakota/North Dakota border. The warm front is difficult to analyze but I have placed it from along the border area to "The Hump" of western Minnesota where there is an apparent wind shift and cumulus deck and elevated thunderstorms developing north of this front. It does appear to trail down into western Minnesota and Iowa but does get washed out at the surface. Further west, a well defined trough extends south of the occlusion through central South Dakota into western Nebraska while, to the west, a dryline is mixing eastward.

Fig (d): Self analyzed 12Z surface plot from the morning of June 17. Warm front is in red, occlusion in purple, trough in brown, and dryline in blue. Also depicts location of surface lows.

By 18Z (1pm CT), the main surface low has lifted into southern North Dakota while the warm front has also lifted into central Minnesota (Fig e). The dryline and trough boundaries have been quickly on the move as well, now both positioned across eastern South Dakota. The low has been deepening as noted by the pressure falls throughout the region and the 994 mb reading at Bismarck, North Dakota. The boundaries are rather noticeable on the satellite image at the same time (Fig f), especially the quickly developing cumulus field across eastern South Dakota ahead of the surface trough. Initiation of storms does occur an hour later on the bulge of the trough as it enters west-central Minnesota. These storms were able to have unimpeded and strong inflow air out of the southeast at 15-25 mph with higher gusts throughout their life cycles, which contributed to the long lived storm and tornado durations and directly resulted in strong wind shear.

Fig (e): Analyzed surface plot for 18Z (1pm CT) on June 17th. Warm front is in red, occlusion in purple, trough in brown, and dryline in blue. Also depicts location of surface lows.

Fig (f): Satellite image at 1745Z (12:45pm CT) on June 17.

Figures g and h depict the surface analysis and satellite image near 22Z (5pm CT) near the time the EF4 tornado impacted Wadena, Minnesota. Notice in Fig g, that Wadena is nearly directly on the analyzed triple point of the occlusion, warm front and trough, which likely enhanced the forcing and low level wind shear of the Wadena storm as it passed through the area. The dryline is also starting to become mixed out and rather diffuse as it enters western Minnesota at this time. In addition, the bulging trough is likely helping to enhance the explosive nature of the storms across southern Minnesota at this time. The inflow winds remain unimpeded out of the southeast, sustained at 15-25 mph with higher gusts ahead of this system.

Fig (g): Analyzed surface plot for 22Z (5pm CT) on June 17th right at the time of the Wadena, MN tornado. Warm front is in red, occlusion in purple, trough in brown, and dryline in blue. Also depicts location of surface lows. Wadena is circled.

Fig (h): Satellite image from 2145Z (4:45pm CT) on June 17th. Notice the explosive development north of Alexandria and also near and south of Mankato.

On the water vapor image below (Fig i), what I thought was very interesting was, not only how evident the explosive nature of these storms were on water vapor, but also the dry punches occurring into the areas that had the strongest tornadic activity. As mentioned earlier, these dry punches likely led to signficant dry air entrainment into the supercells and efficient latent heat release and could have very well been an influence on why there were two seperate areas of tornadic storms while a large area of central Minnesota saw lesser severe weather.

Fig (i): Water vapor image from 2315Z (6:15 pm CT) as strong storms were still taking place across northern Minnesota and large, destructive tornadoes were ongoing across southern Minnesota.

The 300 mb analysis (Fig j) for 00Z 6/18 depicts the upper trough extension into North Dakota with a weak 60 kt jet into Minnesota but a 75+ kt jet streak into the Dakotas with the southeast to northeast flow. Notice that there is quite a lot of divergence taking place the Upper Midwest, especially in southern Minnesota and northern Iowa where the intense tornadic storms were still taking place at this time.

Fig (j): Analysis of 300 mb observations at 8pm CT on June 17.

At 500 mb (Fig k), the 500 mb low is depicted to be across northwest North Dakota with an extension of the 500 mb trough into eastern North Dakota and northern Minnesota. 500 mb temperatures generally range from -8 to -11 across Minnesota. Judging by the wind fields and analysis, there was diffluence at this level taking place across much of the Upper Midwest at this time with mid level jet of nearly 70 kts into Minnesota per the ABR sounding. It would certainly help if MPX would have had a 00Z sounding on this day!

Fig (k): Analysis of 500 mb observations at 8pm CT on June 17.

The shortwave is clearly evident in the 700 mb analysis (Fig l) with a wind shift from eastern North Dakota through central and southern Minnesota and cold advection in the wake of the trough across much of the Dakotas into western Minnesota. Notice the big moisture plume from southeast Nebraska northward to southern Minnesota.

Fig (l): Analysis of 700 mb observations at 8pm CT on June 17.

At 850 mb (Fig m), the dryline/cold front is very evident per the sharp moisture gradient and cold advection behind the boundary. I call this a dryline/cold front because there is little to no surface cold air advection and it appears to all be just aloft, while all of the lower levels are showing a sharp drop in dewpoints/moisture. Notice as well the strong moisture advection into Minnesota ahead of the boundary, wrapping all the way northwestward into the occlusion that is now across southern Canada.

Fig (m): Analysis of 850 mb observations at 8pm CT on June 17.

The figure below depicts the RUC analysis of the 700-500 mb lapse rates at 00Z 6/18. Lapse rates are steep across Minnesota and at 7.5 deg C/km or more, which contributed to the large hail that was experienced with many of the storms.

The figure below depicts the RUC analysis of Mixed Layer CAPE and CINH at 00Z 6/18. A nose of highly unstable air in the 1000-3000 J/kg range stretches from Iowa to north-central Minnesota. This only added more fuel to the fire for explosive supercell development and continued instability for these storms to sustain themselves with the strong inflow.

This image below really tells the story as this is the RUC model analysis of the Effective Helicity values at 00Z 6/18. Incredible Effective Helicity of 450-700 m2/s2 is depicted across all of Minnesota ahead of this system. This is a direct result of the strong southeast inflow winds that were in place this day, and the quick turning of the winds with height across the Upper Midwest. One observation is that the strongest wind shear, possibly 700+ m2/s2 was across northern Minnesota where the lesser instability was in place, but the strongest instability and "slightly" less wind shear was analyzed by the RUC to be across southern Minnesota. I guess it did not matter as all of Minnesota was in a strong severe weather and tornadic environment anyways.

More in-depth information and event summaries can be found through the links below from the local National Weather Service Offices that were impacted this day. The sites include analysis, radar and satellite loops, a breakdown of each tornado and rating, damage surveys, as well as other useful pieces of information. See below:

Twin Cities: https://www.weather.gov/mpx/June172010Outbreak

Grand Forks: https://www.weather.gov/fgf/20100617_tor_outbreak

La Crosse: https://www.weather.gov/arx/jun1710

Duluth: https://www.weather.gov/dlh/jun172010_svrwx

In addition, here are a few radar velocity grabs from when the tornadic storm was progressing close to my hometown of Blooming Prairie, Minnesota. This storm produced two tornadoes very close to my hometown. Notice the strong couplet of inbound and outbound winds to the southeast of Owatonna:

June 17th North Central Minnesota Storm Chase - Tornado Outbreak

June 19, 2010 by Brad in 2010

06-17-10 CHASE LOG: MN

Going into it, I knew this day would have tornado potential but never imagined it would turn into something like this.Peggy Willenberg, her daughter Molly Snyder, and I left the Twin Cities at 9am and headed west to Ortonville, MN where we waited a short while for initiation.Storms fired ahead of a dryline and on a pre-frontal trough near Ortonville shortly before 2pm.These storms took their time maturing while quickly moving north-northeast towards the I-94 corridor.The dryline seemed rather evident with a 20-30 degree dewpoint drop behind the boundary and little to no cold air advection.We followed the storms out of Ortonville on I-75, paralleling the storms to our east till we got to near Tenney.At this point, a pair of storms intensified near Morris, so we traveled east on Hwy 55 to Elbow Lake and then south on Hwy 59 to intercept the stronger storm that became tornado warned as we got on it near Hoffman.The environment for these storms was incredibly sheared and strongly unstable.Forecast hodographs were strongly curved in this area leading up to the event and they seemed to verify due to the strong southeast inflow winds that were gusting 20-30 mph at times and the 0-6 km bulk shear of near 50 kts and could have been higher.RUC Mesoanalysis indicated SB CAPE values of 2000-3000 j/kg helped fuel the explosive development, especially with nearly full sun ahead of the developing CU field leading up the event.The dryline and trough appeared to merge and surge (dryline bulge) upon entering west-central MN and this certainly could have increased the convergence and helped with the explosive development of these storms as well.

As the storm we were on moved north from Hoffman to Brandon and then north of I-94, it encountered the warm front that was slowly lifting through the area.This likely helped enhance the low level shear and lead to the development of the first tornado, and a big one at that, near Leaf Valley Township shortly after 3:30pm.This was a large tornado with multiple vortices that had wedge characteristics at times as it moved north, paralleling and crossing Cty Rd 6 to the north of Leaf Valley.We then drove east on Cty Rd 14 and then north on Hwy 29 to stay ahead of the developing wedge.We intercepted the storm again near Parkers Prairie where the wedge weakened some and became a large elephant trunk, then stovepipe, under a rapidly rotating and very large mesocyclone.We continued to parallel the tornado on Cty Rd 42 out of Parkers Prairie and then Cty Rd 75 towards Wadena.On this path to our west, the tornado grew to a massive size and appeared to be nearly a mile wide at one point and actually looked to have multiple wedge tornadoes on the ground at one time, although I cannot confirm for sure if the leading “wedge” was actually on the ground or another large, low meso that was nearly on the ground and rotating extremely fast.As we neared Wadena, the storm weakened and the tornado lifted as another storm was beginning to take shape and take over to the south of the original tornadic storm.We got through Wadena, north on Hwy 71, and then doubled back into Wadena to see what was on the storm to the south that had a couplet on radar already.Our plan was to head south on Hwy 71 and get just east of the approaching couplet.However, the road was blocked so we had to turn around and head east on Hwy 10 a mile or two out of town and watch the storm approach.Roughly 3 miles south of Wadena, shortly before 5pm, the tornado touched down and grew to massive size, becoming rain-wrapped upon approaching and eventually moving directly through Wadena.This was obviously a helpless feeling for us but we did call in the tornado to the NWS as soon as it touched down south of town.

We then attempted to continue to follow this large tornado on Cty Rd 23 after it had moved north of Wadena and the storm appeared to weaken and no longer have a tornado as we got to near Sebeka.There were more rotating storms moving up from the south so we attempted to stay ahead, traveling south on Hwy 64 to Hwy 210 towards Brainerd.In Pillager, we viewed a large lowering that was very close to the ground on a storm to our north.This was reported by a spotter as a tornado in that area, but I cannot confirm that it actually touched down from how far away we were.

What an incredible day this was as several more tornadoes were reported across the state and a few strong tornadoes that came close to friends and family in northern IA and southern MN.Certainly, I would consider this a tornado outbreak, especially by MN standards.My sympathies are with those that were impacted by the tornadoes, especially those families of the victims and others that lost animals, homes, businesses, and other personal property.

I will be adding more to this chase log over the next several weeks and hopefully finding the time to do a case study on this significant event.

Hail core near Hoffman, MN.

Looking right down the inflow tail into the wall cloud.

Funnel about to drop on the storm near Leaf Valley Township, MN.

Video capture of the tornado near Leaf Valley Township.

Incredible multiple vortex tornado near Leaf Valley Township.

Another video capture of the powerful multiple vortex tornado.

And yet another video capture of the multiple vortex tornado near Leaf Valley Township.

Tornado near Parkers Prairie, MN.

Lightning out of the beast near Parkers Prairie. The wedge tornado was directly behind the lightning bolt.

Massive wedge tornado underneath the huge meso several miles to our west near Parkers Prairie.

Closer view of the huge wedge tornado.

Another large wedge tornado roughly 2 miles south of Wadena, MN.

Large tornado near Wadena, MN.

The wedge tornado ~1 mile south of Wadena, shortly before becoming rain-wrapped and moving into town.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157624188292825/

Incredible velocity couplet at the time we were viewing the massive wedge tornado north of Parkers Prairie, MN.

Strong velocity couplet on the storm as the tornado was going through Wadena. Our position is noted with the dot in the white circle to the east of town. Keep in mind that this is on the outer fringes of the Grand Forks radar.

Storm Reports:

June 1st Eastern Nebraska Storm Chase - Supercell and Brief Tornado

June 11, 2010 by Brad in 2010

06-01-10 CHASE LOG: NE

This chase consisted of MaryLynn and I, and eastern NE looked like the place to be as a Slight Risk was in place for the area with the SPC issuing a 10% hatched area for tornadoes by the 1630Z update.The upper flow was fairly zonal but there was a shortwave trough forecast to swing through the region later in the day that would initiate convection on a stalled boundary that eventually evolved into a cold front.This front was enhanced by a convective complex that moved across the NE/SD border during the morning, which spit out an outflow boundary that intersected the boundary.The plan was to leave Sioux City, IA early in the morning and head south to Lincoln, NE to get ahead.The airmass ahead of the boundary was becoming quite unstable during the afternoon with SB CAPE values of 2000-3000 j/kg with higher pockets of instability.Moisture was not an issue with dewpoints in the upper 60’s, while inflow winds were from the south-southeast at around 15-20 mph.The idea was that any storms that fired in this airmass ahead of the boundary would be supercells with tornado potential due to bulk shear values of 40-50 kts and decent low level shear as well.Storms did not end up firing in this airmass ahead of the boundary due to the lack of any large scale forcing.Storms did fire on the boundary to the north around 1pm and did not look impressive at first and were taking their time to mature/intensify.One storm finally took on supercell characteristics around 3pm near Stanton, NE and this is the storm we went after, traveling north on Hwy 77.As we traveled up 77, the storm was reported to have produced a 5 minute tornado near West Point, NE.We were too late for this tornado, but we did intercept the cell near Oakland, NE.At this point, the storm began to move to the east rather quickly so, to stay out ahead, we progressed on Hwy 32 to Craig, NE and then stair-stepped south and east on some gravel roads.All the while, the storm had cycled with a new, rotating wall cloud.South of Craig at around 4:20pm we observed a large funnel that was moving rapidly northwest to southeast.This funnel got very close to the ground at this point, but we could not confirm that it touched down until a report came in from another storm chaser in the area that a tornado had truly been observed.We were quite a distance away at this point and the reason why we could not tell for sure if it was down or not.Thereafter, the storms began to congeal into a line but our storm continued to show strong signs of rotation embedded in the heavy rain and hail on the line as it crossed I-29 into western IA.Here is where we let the storm core us near Missouri Valley, IA as we were right in the notch and observing a lot of rising motion and several areas of rotation.Thereafter, we attempted to get ahead of the line, traveling south on I-29 through extremely heavy rain, high winds, and small hail, eventually calling it a day as storms had gone completely linear at this point.

Suspicious lowering looking west from Oakland, NE.

Blocky non-rotating wall cloud near Oakland, NE.

Fuzzy picture of reported tornado near Craig, NE.

Our position around the time the picture above was taken near Craig, NE.

Another radar grab from near the time of the tornado and the approximate location of our position as noted by the arrow.

View of the storm on I-29 near Missouri Valley, IA with continued, well defined mesocyclone.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157624131398817/

Storm Reports:

May 26th Eastern Colorado Storm Chase - Slow Moving Supercell

June 11, 2010 by Brad in 2010

05-26-10 CHASE LOG: CO

This log is going to be relatively short and sweet as it did not involve any tornadoes, but it did involve a beautiful storm around 20 miles northeast of Denver, CO.Our group consisting of guests and guides for Silver Lining Tours left Lamar, CO by late morning and traveled north and west to intercept an intense storm that had already fired over Denver by early afternoon and was moving over the airport.Before we intercepted, the storm produced several landspout tornadoes as well as a funnel directly over the Denver International Airport.We intercepted the supercell northeast of the airport and observed the storm for several hours in this area as it was only moving northeast at 10 mph.Several lowerings and wall clouds were observed during this time and even a period of rapid condensation/rising motion where we all thought the storm was going to produce a tornado right in front of us.Even though the storm was tornado warned several times, this storm just could not get things together and drop a tornado but it did have beautiful structure, having a “mothership” appearance much of the duration of the storm and, at one point, a soda can appearance as the storm had a twisted look to the updraft.In addition, we experienced large hail to around ping pong ball size and some stones even larger as we let the hail core come overhead on a couple of occasions.Towards evening, we bailed on the northern storm as another was looking strong and coming at us from the south.This cell ended up dying as we intercepted near Strasburg, CO so we ended the chase here after taking pictures of an amazing sunset as more storms fired to our west over Denver.

View of supercell over Denver as we are approaching from the east on I-70.

Rapidly rising motion into wall cloud northeast of Denver International Airport.

Continued rapid rising motion and rotation on lowering northeast of Denver International Airport.

Incredible soda can appearance to this supercell.

Structure of the storm.

Another storm firing on the mountains near Denver at sunset.

Another view of the developing storm at sunset.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157624130890455/

Storm Reports:

May 25th Southeast Colorado and Southwest Kansas Storm Chase - Supercells and a Surprise Tornado

June 11, 2010 by Brad in 2010

05-25-10 CHASE LOG: CO/KS

This was a successful chase day in a Slight Risk area of southeast CO where we intercepted several supercell storms and saw an incredible tornado near Bartlett, CO.We had a long drive ahead of us already as we left Valentine, NE in the early morning and were targeting somewhere around Johnson City, KS.Our drive took us south on Hwy 83 through western KS and then west on Hwy 50 as a pair of supercells, one that had developed across southwest CO and another across the OK Panhandle.We originally decided to target the southern storm on the dryline, but the other storm was showing strong signs of rotation and close to crossing a stalled boundary around Hwy 96 to the north of Lamar.Upon reaching Johnson City, KS we went west on Hwy 116 and then north on Hwy’s 89 and 385 to near Sheridan Lake to intercept the storm that had already produced several landspout tornadoes.We did see a lowering and funnel upon approaching the storm, but it quickly weakened and became a big HP mess upon moving to the north of the boundary in the more stable air.

Our original targeted storm well to the south, which was now a tail end Charlie storm as others had filled in between, had been and continued to be tornado warned.This storm was only moving north-northeast at around 5 mph so it would be an easy intercept.We progressed south on Hwy 287 and then east on Hwy 116 to intercept this storm near Manter, KS.The supercell was still warned at this point and had unbelievable structure, while all the while having a big, rotating wall cloud underneath for around an hour.Another, beautiful LP storm was visible to the north and very photogenic.This supercell was barely moving at all so we were able to view from a close distance for over an hour before we decided that it was not going to do very much, plus it was looking rather high based with weak inflow winds.Wanting to see some of the large hail from this storm, we traveled south on Hwy 160 to near the small town of Bartlett, CO.Here we continued to watch the storm from the back and check out the ping pong ball and a few stones near baseball size that had fallen out of this storm earlier.After sitting for about 20 minutes, the storm started to have a lot of rising motion and then what appeared to be outflow on the southwest side.To our BIG surprise, the area of outflow started to have very fast and rotating rising motion and produced a funnel that quickly became a large cone tornado right in front of us!This was clearly not expected as the other vans had to be alerted to the oncoming tornado via radio and managed to get out just in time to view the tornado at a safe distance, but at very close range for around 3-4 minutes.Really, this was an unbelievable surprise to have this storm produce a tornado just before sunset, especially since it was not showing any signs of rotation before this tornado spun up.Clearly seemed like a “freak of nature” tornado more than anything and one that I will never forget.

Low precipitation storm with incredible lowering near Manter, KS.

Big Liberty Bell shaped lowering with funnel on storm near Manter, KS.

Another big funnel forming on the supercell near Manter, KS.

Tornado near Bartlett, CO!

My favorite shot of the tornado near Bartlett, CO.

Tornado starting to rope out.

Tornado in rope out phase.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157624254094536/

Storm Reports:

May 24th Southern South Dakota and Northern Nebraska Storm Chase - Supercell Storm and Mammatus

June 06, 2010 by Brad in 2010

05-24-10 CHASE LOG: SD/NE

This was a difficult chase day with a strong storm system and fast moving storms in a large Moderate Risk for severe storms.A low pressure system was forecast to progress from western SD into southwest ND during the day with a warm front quickly lifting northward from near I-90 to the SD/ND border by evening.A dryline and cold front were expected to move into western SD and western NE through the day.After several long chases in a row, our group decided to meet by late morning in Valentine, NE and then head north on Hwy 83 to Murdo, SD.Storms already began to fire around midday ahead of the triple point near Rapid City, SD and additional storms began to fire on the warm front lifting north of I-90.Storms all day were moving at nearly 55-65 mph on average so anything that got by us was long gone.We decided to attempt to intercept a tornado warned storm near Rapid City, but soon realized that a storm ahead of the triple point on the warm front would be the storm of the day.This was our original plan was to play any storms in this area but, due to the late start in the day, we could not get to this storm in time to see the large tornado it did produce near Faith, SD.More storms began to fire in the warm sector in a highly sheared,unstable, and moist environment in central NE and move north towards our area, so we ended up bailing on the cell near Rapid City and turning around in Wall, SD and traveling back to Murdo, SD.Just east of here is where we intercepted our first storm of the day near Draper.This storm was severe and had nice structure and actually a nice rotating wall cloud for quite a while.Other storms were firing to the south into the early evening, while the storm we were on was not looking overly impressive so we ended up heading back south on Hwy 83 back towards Valentine, NE and intercepting a squall line about 20 miles north of town. This line had a messy shelf cloud, some gusty winds, and heavy rain, but nothing that was all too impressive.

Storm with lowering near Draper, SD.

Storm with rotating wall cloud near Draper, SD.

Incredible mammatus in Valentine, NE.

Mammatus in Valentine, NE.

More mammatus at sunset in Valentine, NE.

More photos from this day can be found here:http://www.flickr.com/photos/39991047@N02/sets/72157624218639078/

Storm Reports:

May 23rd Northwest Kansas Storm Chase - 3 Tornadoes Including a Nighttime Tornado Near Goodland

June 05, 2010 by Brad in 2010

05-23-10 CHASE LOG: KS

After an incredible chase the day before where we witnessed the Bowdle wedge tornado and 5 other tornadoes, our tired crew left Winner, SD early this morning and targeted northwest KS in a Slight Risk for severe thunderstorms per SPC.There was an area of low pressure that was expected to develop across northeast CO with a trailing dryline through eastern CO and a stalled boundary across northeast CO into southern NE.With a stout cap, thunderstorms took until nearly early evening to initiate and then took until sunset and after to mature.We targeted storms along the triple point but, as a few storms started to develop further south along the dryline, these storms began to rotate and soon became tornado warned.Our route was to progress west from Oakley, KS on Hwy 40 and then north on Hwy 27 as storms moved nearly due north, paralleling Hwy 27 towards Goodland.Two short-lived rope tornadoes did touch down right at sunset to the southwest of Goodland to the west of Hwy 27.However, the most significant tornado touched down 9 miles NNE of Goodland.This tornado was what appeared to be a rather strong, cone tornado that was visible through the occasional lightning.This tornado appeared for around a minute and then disappeared.Our course then took us north to Hwy 36 east where we took some lightning shots near Bird City. I cannot be disappointed with this day with 3 tornadoes and a pair of nicely structured supercell storms!

Storm first going up with abondoned shed in the foreground.

First funnel of the day!

Incredible storm structure on the LP storm near Sharon Springs, KS.

Wall cloud dragging on the ground on the tornado warned storm near Goodland, KS. Shortly after this produced two different, weak spin-ups.

Storm being lit up by lightning near Bird City, KS.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157624088058263/

Storm Reports:

May 21st Wyoming and Nebraska Storm Chase - One Tornado and a Funnel

June 05, 2010 by Brad in 2010

05-21-10 CHASE LOG: WY/NE

The target this day was in the upslope regimen of the Cheyenne Ridge through southeast WY with storms expected to develop in the mountains and move out into the High Plains area during the mid to late afternoon.Our group left Colby, KS in the morning and progressed northwest to Cheyenne and then north on I-25 toward Chugwater, WY as a pair of intense storms were already firing on the Laramie Range and about to move off the mountains into the open High Plains.Consequently, this is where the better environment was at with moderately strong heating indicated by SB CAPE values in the 1500-2500 j/kg range, dewpoints adequately into the upper 50’s in a higher elevation area, and strong east-southeast winds at 20-30 kts which led to strong inflow and low level shear.In addition, these storms developed in an area of higher bulk/deep layer shear values of 40-50 kts and could have been higher with a shortwave moving through the region and helping to ignite convection.

Upon approaching the storm near Chugwater, it quickly produced a short-lived rope tornado that we did see from 15 miles south of the storm.This tornado touched down near Wheatland, WY.Being so far away from the storm at the time of the tornado, we were not positive that it touched down after seeing the funnel ¾ of the way to the ground, but confirmation came from spotters and chasers in that area that it did indeed touch down around 5pm.The tornado dissipated as we followed to the south of the storm on Hwy 316 and then north in Hwy 160 towards Fort Laramie, WY as the storm continued to right turn and actually take a more east-southeast movement.A couple of rotating wall clouds were seen along the storm path, as well as a very interesting lowering on the left split storm to the north of ours that did end up becoming tornado warned.Our storm ended up moving out into an area with no roads upon crossing the WY/NE border so we ended up going north on Hwy 85 towards Lusk, WY and then east on Hwy 20 where we intercepted again near sunset in Crawford, NE.We witnessed a spectacular lightning show before ending the chase here and traveling to Valentine, NE for the night.

Tough to see, but this is the tail end of the tornado way in the distance near Wheatland, WY.

Lowering underneath a new updraft on the storm near Wheatland, WY.

Another storm coming off of the Laramie Range in WY.

Two new explosive updrafts on our storm east of Wheatland, WY.

Horizontal funnel forming on the leading edge of the RFD clear slot.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157624087897675/

Storm Reports:

May 19th Oklahoma Storm Chase - 3 Tornadoes from a Long Lived Tornadic Supercell

June 05, 2010 by Brad in 2010

05-19-10 CHASE LOG: OK

This ended up being by far the worst chaser convergence I have every experienced and a rather stressful day, although we did see several funnels as well as a terrific rain wrapped tornado near Dover, OK.I was chasing for Silver Lining Tours and this was our Day 2 after seeing 4 tornadoes on day 1 of the tour.We woke up in Amarillo, TX to a moderate risk across much of OK and, while traveling east to our target area, the Storm Prediction Center upgraded to a High Risk for the potential for a severe weather and tornado outbreak.An MCS had gone through during the overnight and dropped an outflow boundary that intersected the warm front from northwest to southeast across OK.This likely helped to enhance the low level shear along the boundary.A surface low was forecast to move into northwest OK during the afternoon with a dryline mixing east into western portions of the state as well.Extreme instability of 2500-3500 j/kg and strong low and deep layer shear was forecast to develop ahead of the dryline and along the warm front during the afternoon on the 19th.The idea was to wait in Clinton, OK and wait for initiation either on the triple point, warm front, and/or dryline.There were also upper 60’s and lower 70’s dewpoints feeding into this area so moisture was a big bonus.

The triple point produced the first storm of the day shortly before 3pm and we waited for a half hour in Clinton until we were sure this would be the storm to go after.More towers were going up on the warm front and dryline and they were sure to fire soon, but the storm that was now west of Leedey, OK was really starting to look terrific so we took off after that north on Hwy 183 and west on Hwy 47.The storm produced a brief tornado near Leedey, before we got on it, but we did manage to see the tail end of the tornado from around 6-8 miles away as it was lifting.This storm had intense, new updrafts going up on the flanking line to the southwest of the storm with several nice wall clouds as each updraft went up.

The supercell was drifting to the east at 15-20 mph but it quickly became apparent that chaser convergence was going to be a major issue as this storm was continuing to progress into a more favorable environment and was the best storm anywhere in the country.Hundreds of chasers converged on this cell and Hwy 33 from Watonga to Kingfisher became a mess of chasers battling for position while trying to stay out of each other’s way.The storm kept recycling wall clouds and several funnels were noted on the route as we attempted to stay ahead of the storm.Near Watonga, the storm produced a rapidly rotating mesocyclone and we were barely able to stay head of a developing tornado at that time.Upon moving towards Kingfisher, we decided to travel north on Cty Rd 2740 and then east on Cty Rd 720, just ahead of the hook on radar and clearly in the notch as the hail core began to wrap around with the rear flank downdraft.Approaching the Dover area, the storm dropped a rain wrapped, cone tornado only around a half mile from the road which is seen in the photos below.We attempted to stay ahead of the tornado and wanted to drop south and get ahead of it, but were blocked by other chase vehicles and the tornado managed to cross the road directly in front of us and then off into a field very close to our position.The tornado was rain wrapped but I did get some short video of it at that time.In addition, this tornado did reportedly produce some damage to a farmstead in this area.

Lowering underneath the updraft of the storm north of Aledo, OK.

Intense, new updraft on the storm as we first got on it north of Aledo, OK.

Rain wrapped cone tornado!

Another shot of the tornado near Dover, OK. This thing almost ran us over due to other chasers blocking the road in front of us!

Edge of the mesocyclone of the supercell.

Another storm going up well to the south at sunset.

More photos can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157624106808676

Storm Reports:

May 22nd South Dakota Storm Chase - The Bowdle EF4 Wedge Tornado

May 23, 2010 by Brad in 2010

05-22-10 CHASE LOG: SD

This chase definitely tied with June 24th, 2003 as the best chase of my life! We started the day in Valentine, NE after chasing and seeing a brief tornado in eastern WY the day before. There was an area of low pressure that was progressing towards central ND with another low that was expected to reach central SD by late afternoon. Ahead of this low a warm front stretched from near Pierre, SD down into southeast portions of the state and was slowly lifting northward through the afternoon, as a cold front south of the low slowly worked eastward as well. The idea was to play the triple point near these boundary intersections as models had continued to develop storms ahead of this feature and some held off storms till evening further south where a stout cap was in place, per the special 20Z observed sounding out of Aberdeen that indicated +18 deg C at near 800 mb. There must have been an amazing amount of forcing and convergence on the triple point, because several towers developed by late afternoon and a big storm broke through to the west of Akaska, while we were positioned to the southeast near Gettysburg. This was an incredible environment for this storm to go up in as dewpoints ranged from the upper 60’s into the lower 70’s and even a few 74 degree dewpoints pooling along the warm front and triple point. In addition, it was very unstable with a nose of 4000-6000 j/kg of SB CAPE poking up into the region in a strongly sheared environment due to the southeast winds near 20 kts and some locations gusting over 25 kts at times. The dry punch into the region from the southwest, as indicated by the drop in dewpoints, likely helped convergence as well and possibly a forecast shortwave that was forecast to move into central SD at the time storms initiated.

The storm quickly became tornado warned near Lowry and produced a lowering with rotation soon after. The first tornado of the day dropped northeast of Lowry as a stovepipe and then became an elephant trunk and appeared to weaken. However, the circulation gained intensity upon moving close to us on Hwy 47 and we quickly moved north to stay ahead of this tornado. The tornado crossed Hwy 47 and Hwy 12 shortly after we had moved east and observed the tornado at close range to the road. This is where the tornado downed powerlines and poles, blocking the road from anyone wanting to travel east and stay with the tornado. As we moved towards Bowdle, our plan was to head north on Hwy 47 and observe this tornado that was holding together.It quickly grew into a wedge tornado to the northwest of Bowdle and we were able to experience this mammoth beast at close range as the track continued to take it to the east-northeast. About 1 mile west of Hwy 47 is where the wedge, unfortunately, appeared to hit a couple of farmsteads and one of the families was in their vehicle right next to ours, watching their home get destroyed. It was a sad moment as we tried to console them over their eventual loss.

At this point, we became cut off from heading north and needed to head back on Hwy 47 back towards Bowdle and through the RFD winds that were very strong just north of town. We then traveled east on Hwy 12, observing a second tornado near Roscoe and then 3 more weak elephant trunks northwest and then 4-5 miles north of Ipswich. Here is where the storm became very HP and we bailed south on another tornado warned storm near Faulkton where we witnessed incredible storm structure and a couple of funnels that could not quite make it to the ground. What an amazing chase day and one I will never forget!

Storm going up right on the triple point near Lowry, SD.

First tornado of the day to the northeast of Lowry, SD.

Same tornado starting to become more of an elephant trunk and weaken.

Tornado to our southeast as we were driving on Hwy 12 trying to stay ahead of it.

Wedge tornado on the ground to the northwest of Bowdle, SD.

Getting closer to the incredible wedge tornado near Bowdle, SD. Probably the number one tornado of my life so far to this point!

Second tornado of the day touching down very close to Roscoe, SD.

The tornado near Roscoe and the storm structure.

Closer view of the tornado near Roscoe, SD.

The third tornado of the day touching down northwest of Ipswich, SD.

Blurry photo showing the fifth tornado of the day around 4-5 miles north-northwest of Ipswich, SD.

A different storm near Faulkton, SD with awesome structure and stacked plates.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157623992903309/

Radar image around time of the wedge tornado:

Velocity image around time of the wedge tornado:

Storm Reports:

May 18th Texas Storm Chase - 4 Tornadoes and a Beautiful Supercell Storm

May 21, 2010 by Brad in 2010

05-18-10 CHASE LOG: TX

This was a Moderate Risk day from eastern CO southward through western TX with good promise of producing tornadoes, fairly well forecast several days in advance.I was driving for Silver Lining Tours and this was Day 1 so we wanted to get a good chase in right away.The tour group flew into Oklahoma City, OK the day before and we left there in the morning to target Dalhart, TX for late afternoon initiation.There was an upper level trough that was starting to move out into the High Plains late on the 18th and a low pressure system had been developing through the day across northeast CO.This system had already produced a few strong supercells that were already tornado warned across eastern CO by mid afternoon.The one concern in our area was the limited moisture as dewpoints were only in the upper 50’s, and that this would lead to high cloud bases and more of a damaging wind threat and limited tornado threat, even with decent low level shear.As the dryline began to mix out of the Rockies and the backed, southeast surface winds began to increase and become sustained at near 20 kts by the afternoon, convergence ahead of the dryline began to significantly increase and led to intense development of a storm shortly after 4pm only around 10-15 miles southwest of Dalhart where we were already in place.This storm quickly had 55,000 foot tops and went severe with very large hail rather quickly as we intercepted.Right away the storm produced a large, rotating wall cloud near Hartley, TX but we became blocked from getting ahead of the storm due to the baseball sized hail that was falling out of the core and blocking our east route.We waited behind the supercell southwest of Hartley at this point until the core had passed and then we progressed east on Hwy 87 towards Dumas.Upon moving through Dumas and then due east on Hwy 152 towards Stinnett, the storm produced 3 very brief and weak tornadoes.I was not able to get pictures or video of the first 3 tornadoes of the day as I was driving the vehicle.This storm did have some of the most amazing structure of any storm so far this year and was truly a sight to see as we followed the very slow moving storm due east.Near Stinnett the storm began to produce a huge mesocyclone and this is where we saw a stovepipe tornado just to the northwest of town.Thereafter, the storm began to lose organization and it was getting dark so this was the end of the chase day.Definitely a good way to start a 10 day storm chasing trip!

Beautiful structure already on this storm around 8 miles southwest of Hartley, TX.

Rapidly rotating wall cloud with possible large funnel underneath this storm to the east of Hartley, TX.

Inflow tail to the wall cloud with scud rising into the base that is nearly on the ground at this point.

Amazing structure on this storm near Dumas, TX! Starting to get a laminar shape and big hail core in there.

Another shot of this storm near Dumas, TX.

Stovepipe tornado touching down near Stinnett, TX!

Closer shot of the stovepipe tornado near Stinnett, TX.

Another shot of the beautiful stovepipe tornado!

More photos can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157623978621641/

Storm Reports:

April 30th Eastern Iowa, Northern Illinois, and Southern Wisconsin Storm Chase - Lightning and a Lowering

May 03, 2010 by Brad in 2010

04-30-10 CHASE LOG: IA/IL/WS

Not too special of a chase overall with a lot of miles put on, but it was fun regardless. Peggy Willenberg, Melanie Metz, and I left Council Bluffs, IA after bagging a tornado and some amazing supercells near Washington, KS the day before. Our plan was to get ahead of a cold front and chase a line of storms racing east of Des Moines, IA already by midday. We raced east on I-80 into eastern IA and finally managed to get ahead of the storms near Iowa City, IA. Storms were moving to the northeast at 60-65 mph so it was nearly impossible to stay with them, so our only hope was to get ahead of the line and wait for a strong storm to come up at us from the southwest. A few finally did as we approached Davenport, IA and I did manage to get some video and screen captures of the occasional cloud to ground lightning. Storms that managed to stay discrete did have nice bases and even a few visible updraft areas, but everything was rather embedded and tough to see. The Storm Prediction Center issued a tornado watch for much of IL into southern WI as we got into eastern IA as this area was very highly sheared and destabilizing ahead of the front. However, it became fairly clear as we entered into IL that storms were going to be more of a linear mode along this front with the strong forcing and a 100 knot 500 mb jet, albeit in a very highly sheared environment. A decent storm developed to the north of Sterling, IL and was moving northeast towards southern WI. We traveled north on I-39 and I-90 to near Janesville, WI where we intercepted and watched the storm pass, which had a nice base and cloud to ground lightning. After that, it was time to start heading home as everything became very messy. As we passed through Madison, WI, I noticed on radar some rotation coming at us from the southwest with what looked like some sort of mesolow. We ended up intercepting this storm near the Arlington, WI exit where there was a lot of motion and even a wall cloud that I did not get a picture of since I was driving. This storm later produced a tornado to our northeast in Green Lake County, WI.

Screen capture of lightning strike near Davenport, IA.

Lightning screen capture from storm near Davenport, IA.

Cloud to ground lightning strike near Janesville, WI.

Nice base and updraft of storm near Davenport, IA.

What appeared to be a wall cloud starting to form on cell near Janesville, WI.

Storm Reports:

April 29th Northeast Kansas and Southeast Nebraska Storm Chase - Washington Tornado, Several Wall Clouds, and Massive Shelf Cloud

May 01, 2010 by Brad in 2010

04-29-10 CHASE LOG: KS/NE This ended up being a great chase with several wall clouds, 1 tornado near Washington, KS and probably the best shelf cloud I've ever seen near Belleville, KS. Our chase group consisted of me, Peggy Willenberg, and Melanie Metz. The plan was to stay in Council Bluffs, IA the night before and then target extreme north-central to northeast KS for Thursday's event. Concerns for the day were the lack of moisture and how fast the upper 50's to around 60 dewpoints were going to make it into the area as well as the presence of a rather stout cap as indicated by the morning observed soundings on OAX and TOP. These concerns were alleviated as we traveled down to Concordia, KS to position during the early afternoon and dewpoints were already in the upper 50's with a small pool of lower 60's in northeast KS as moisture had been quickly advected north with the 25-40 mph surface winds and nearly 60 knots at 850 mb over the past 12 hours. Morning forecast models were cooling temperatures aloft across the area as well so there was optimism the cap would break before dark. This was a day of very good low and deep layer shear with modest instability.

By mid-afternoon, a line of enhanced cumulus began developing, out of seemingly nowhere, along the dryline/boundary that was draped from southwest to northeast across the state. Feeling was that this was a dryline due to the 8-10 degree dewpoint drop behind the boundary. We positioned around 8 miles north of Minneapolis, KS at this time to watch the development take place. Within an hour, high based convection began to fire and nice cell started to form to our north. Wanting to get on the first cell of the day, we drove north on Hwy 81 and then east on Hwy 24 and then north on a gravel road through Aurora and (appropriately named) Nelson townships. The storm was starting to get its act together at this point and we could definitely see a nice hail shaft. Trying to take a muddy and slick road east, our truck began to slide and nearly put us in the ditch. However Peggy was able to maintain control and back out to the road we came from. Heading north we finally reached a paved road and went east on Hwy 9 to near Clyde. Our storm had a small lowering at this point but had several updrafts and was starting to become rather messy, while another cell was firing to our southwest. We bailed on the northern cell and went west on Hwy 9 to intercept this new cell that was rapidly developing near Concordia, KS. As we got on this cell on the north side of Concordia, the storm produced a very nice and blocky wall cloud, not rotating at this time but it was the first good indication that the storm was surface based and developing quickly. Cloud bases were lowering dramatically at this point as LCL’s started to come down. As we followed north on Hwy 81 and then east on Hwy 148, the meso began to rotate produced a couple of very picturesque wall clouds to the north of Hwy 148 to the southwest of Washington. Following the storm north on Hwy 15 and then east on Hwy 36 the storm produced a rapidly rotating wall cloud that stirred up a short lived tornado, as indicated by a debris cloud, shortly after 7pm to the north of Washington, KS. After producing the tornado, the storm became loosely organized till there was no wall cloud or even a lowering visible. We decided to bail on this storm around Odell, NE and travel west on Hwy 8 towards Fairbury, NE where a tornado warned storm was moving up from the southwest. Upon moving south of Fairbury on Hwy 15, the storm began gusting out and produced the best shelf cloud I've ever seen! The shelf looked like a snowplow with teeth and was nearly vertical at the front edge, seemingly very near the ground. An interesting feature was noted just to the west of Fairbury at this point where there appeared to be a large wall cloud and possible funnel very close to the ground, becoming embedded in the rain and hail core. A tornado was never reported here but it would not surprise me if one touched down at this point. Wanting to stay ahead of the shelf and not get cored, we traveled back east on Hwy 8 and then ended the chase at this point as night fell.

Big rotating wall cloud to the northeast of Concordia, KS.

Scud being rapidly lifted into the base with strong inflow to the northeast of Concordia, KS.

Incredible, well lit wall cloud wrapping up near Agenda, KS.

Backlit, rapidly rotating wall cloud to the southwest of Washington, KS.

Blocky wall cloud transition taking place with strong rising motion near Washington, KS.

Wall cloud reaching towards the ground shortly before tornado touchdown near Washington, KS.

Very close to the time the tornado near Washington, KS was reported. We did see a brief debris cloud at the base, which you can see in the video below.

Awesome looking shelf cloud near Fairbury, NE. Even better in the video.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157623847576173/

Base Reflectivity near time of Washington tornado:

Storm Relative Velocity near time of Washington tornado:

Storm Reports:

April 23rd Eastern Nebraska Storm Chase

April 25, 2010 by Brad in 2010

04-23-10 CHASE LOG: NE

This ended up being a somewhat disappointing chase overall, but it was certainly good to just see some storms!Our group consisted of me, MaryLynn Nelson, Peggy Willenberg, and Beau Gjerdingen.The forecast was for severe storms to develop across eastern NE on an occluded front, warm front, and dryline by the late afternoon hours and especially into the early evening.After staying in Omaha the night before, our course of action was to drive to Lincoln, NE and re-evaluate towards midday.Storms were already starting to fire on the occlusion to our west at this point and a tornado watch has been issued for this area.After a few hours, we traveled to York, NE on I-80 thinking that these storms could develop back down on the boundary and we could at least have a look at them.The Interstate also offered a quick escape east in case additional storms would fire across eastern NE where the better moisture and low level shear resided.Storms did not end up building down the boundary and the dryline was quickly approaching our location with the occlusion being lifted well north.A nice cumulus field began to develop across far eastern NE and northeast KS, so we ended up moving east on I-80 all the way back to Omaha in the vicinity of the moisture and convergence axis.Our first storm of the day began to develop around 15 miles south of Omaha near 6pm.This storm was moving due north-northwest towards our position so we stayed put.All the while, new storms and turkey towers were starting to form all around us but were finding themselves very difficult to break the cap and sustain their updrafts.The aforementioned storm did end up moving just to the west of our position while new storms developed along a convergence boundary near Lincoln, NE.These storms near Lincoln quickly went severe with large hail and even a tornado warning but we decided to stay on the more northern cell, following the storm north on Highway 133 out of Omaha towards Blair.As we approached the base between Omaha and Blair, we headed west on a dirt road and found ourselves staring at a beautiful vault/updraft and lowering underneath the storm.At this time, the anvil started to produce some nice mammatus as well.This storm ended up weakening some and new updrafts were starting to our north so we continued to follow these cells to the northwest towards Fremont and then eventually to West Point, NE where we finally gave up the chase and ended up core punching into some pea size hail.South of West Point, we did see a nice non-rotating wall cloud that only stuck around for several minutes or so.

Definitely a disappointing chase considering how good the low level shear along the boundaries was forecast and how it looked per the Mesoanalysis during the event.One thing that I was very worried about before the event was the lack of upper level winds.The main upper level jet had been forecast and ended up being well south of the area and the reason why portions of MO ended up having quite a bit of severe weather.In addition, there was a stronger cap than expected as shown on the special 20Z sounding out of Omaha.This was even more evident on the Topeka sounding.Another factor was the late arrival of the shortwave to the area that finally made it by 00Z ignited all the storms in the area during the evening and primarily after sunset.I also noticed that the inflow into these storms was quite chilly but with dewpoints around 60 degrees so moisture was not much of an issue.

Storm updraft developing very quickly directly over Omaha, NE.

Beautiful vault and base on this storm near Omaha, NE.

A closer view of the storm base and associated strong updraft region of storm near Omaha, NE.

Fuzzy picture of brief lowering on storm near West Point, NE shortly after sunset.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157623800381923

Storm Reports: