2001 STORM CHASE ACCOUNTS

MARCH 11: NORTHWEST-NORTH TEXAS (Weak Thunderstorm/Funnel)

Jim Kaiser, Brian Thalken and I decided to head down to Norman, Oklahoma on Saturday March 10 in order to be in position for a potential chase on Sunday March 11.  As Sunday rolled around, it appeared that conditions would be favorable for a few severe thunderstorms from Southwestern Oklahoma south toward the Rio Grande River in South Texas.  As can be seen on the 11 March 12 UTC surface map, a surface low is starting to develop over far West Texas, and our chase group anticipated this low and a trailing dryline to move east/northeast during the day, providing focus for severe thunderstorm development by mid to late afternoon.  In addition, this area was outlooked by SPC as a slight risk for severe thunderstorms, with the main threat being large hail.

After several hours of analyzing obs, satellite images, and model forecasts we decided to depart from Norman at around 11 AM with a target zone 50 miles south of Wichita Falls, TX.  The drive southwest down the H. E. Bailey turnpike in Southwest Oklahoma was dreary with low cloudiness, cool temperatures, and occasional drizzle accompanying us until we reached the Red River a little after noon.  After eating lunch in Wichita Falls, we then headed ~30 miles south along highway 281 where we were greeted by clearing skies.  This not only allowed temperatures to rise into the upper 60s and instability to increase, but also allowed us to observe the developing TCUs' to our west and southwest.  We then decided to stop south of Windthors, TX at around 2:30 PM and wait for additional development to our west (Photo #1).    

After two hours of throwing rocks at telephone poles, a large tower with a maturing anvil developed to our northwest near Archer City, TX at around 4:30 PM.  We quickly departed in order to intercept this storm as it appeared the other Cu's to the southwest were having a hard time developing.  After moving to the west of Archer City, we then positioned ourselves about three or four miles to the southeast of the developing storm.  To our surprise, at ~ 4:50 PM, a small lowering began to protrude from underneath the base of a vigorous flanking cell updraft (Photo #2).  This lowering continued to develop into a slender funnel (Photos #3, #4, #5, #6, #7) but struggled to reach more than half way to the ground and dissipated ~5-10 minutes after we first noticed it.  The parent cell then continued to develop and showed signs of mid-level rotation.  A small inflow band developed on the southeast flank (Photo #8) and we thought things might continue to get interesting, however, this storm fizzled out during the next 20 minutes, and it appeared that every other convective tower went through the same process, therefore we called off the chase at around 6 PM and made the quick two hour drive back to Norman.  It appears to me after further analysis that a deep layer of low-level moisture was missing, and the main dynamics of the synoptic-scale storm system were lagging behind to the west.  Still, we are very happy with the results of our first chase of the season, being able to observe one funnel produced by a fairly impressive March thunderstorm complex against a backdrop of clear blue skies and the West Texas countryside.     

Additional pictures can be found at Brian Thalkens homepage.

APRIL 6: WESTERN KANSAS (Squall-line/Bust)

This day had the potential to be the first severe weather outbreak of the season over the Central and Southern Plains.  SPC issued a High Risk for severe thunderstorms, including the potential for strong tornadoes over much of Kansas and portions of Oklahoma and Texas.  So the chase group from UNL eagerly departed Lincoln, NE toward a target zone between WaKeeney and Colby, KS.  To make a long story short, our group ended up near Scott City, KS at around 6 pm as a line of thunderstorms developing to our west progressed eastward.  A tornado watch was issued shortly before this time but we soon realized that the convection to our west was un-chaseable as cells raced to the north at 80 mph.  We decided to let the cells move toward us, but everything looked messy and we decided to head east and avoid any large hail.  All in all, it was a long drive with little pay-off as far as severe weather was concerned, but we did encounter some nice scenery.

An additional chase account and pictures can be found at the Nebraska Weather and Climate Websight.

APRIL 8: NORTHEAST KANSAS-SOUTHEAST NEBRASKA (Night-chase/Tornado Warned Cells)

Fellow Nebraska storm chaser Steve Peterson and I decided to head south from Lincoln, NE toward Northeast Kansas where the potential for convective initiation and possible severe thunderstorm development existed.  A warm front was moving north past the KS/NE border during the day with mid 80s temperatures and low 60s dewpoints present south of the boundary, and a subtle dryline was present near Manhattan, KS.  We decided to wait near Havensville, KS for convective initiation, but by 6 pm, it appeared to us that nothing was going to pop, so we began to head back north toward Lincoln.  However, this was the time when thunderstorms began to fire about 20 miles to our east.  So we decided to investigate these towers and ended up in Hiawatha, KS, but we soon concluded that they where high based and thus not to promising.  So we again headed back north, noting a large convective complex moving east through Nebraska.

A severe thunderstorm watch was issued for this complex of storms and several warnings had been issued for a few Eastern, NE counties.  As we entered Auburn, NE, a tornado warning was issued for Gage, County Nebraska which is south of Lincoln, NE.  So Steve and I decided to wait out the warning in Tecumseh, NE and hope we could catch a glimpse of any menacing low-level features to our west.  This complex moved very slowly and we ended up waiting several hours for it to pass.  Two additional radar indicated tornado warnings were issued for our area during this time but we never saw anything resembling a low-level mesocyclone.  We did eventually witness a brief hailstorm as the complex moved over us.  We finally arrived back into Lincoln shortly before midnight.

APRIL 11: SOUTHWEST IOWA (Mini-supercells)

The group from UNL left a little to late today (around 12:30 pm) to make it out to the high risk in Eastern, IA, but still managed to catch a couple of supercells in Southwest, IA.  As we were moving east out of Council Bluffs, IA on I-80, we witnessed a nice funnel which lasted five minutes (observed at ~ 1 pm).  We then continued to follow the parent supercell north.  It had some nice low-level features including a vigorous low-level mesocyclone, however, it was forming along the northward moving dryline and likely entrained a lot of dry air into its updraft which caused it to dissipate.  Our group then moved east into Shelby, County IA, intercepting two or three more supercells, each which had tornado warnings on them, but each low-level mesocyclone dissipated after 10-15 minutes due to the amount of dry air surging into their updrafts.  We decided to call off the chase by 3 pm in Crawford, County IA, and arrived back into Lincoln two hours later.  This day was fairly dynamic and produced some nice looking supercells in Western, IA, which provided for some nice structure shots and a few brief photo opportunities of funnel clouds.

APRIL 22: SOUTHERN NEBRASKA (Supercell)

Another moderate risk day according to SPC for the eastern half of Nebraska, parts of Kansas and Iowa.  The most interesting part of todays chase started during late afternoon as storms fired up east of Alma, NEB or west of Riverton, NEB. We followed one cell toward the north which had excellent mid-level rotation. As we got closer to its base, we immediately noticed how low the LCLs were, in fact, we could see steam rising off the ground and cloud tags eventually condensing and streaming into the updraft. Further excitement ensued when an RFD became apparent, with the clear slot starting to wrap around the updraft base. I thought it was only a matter of minutes before a tornado would form because scud was rising into the middle of the updraft base, with the RFD focusing rotation (Photos #1, and #2). This cell was southwest of Minden, NEB and still looking great, when all of a sudden, it just gusted out and took on a very non-tornadic appearance. 

We then headed east and arrived in Hastings, with the same group of storms just to our west. I can't remember the exact time, but a tornado warning was issued for a cell to our west in Adams County so our hopes rose a little more. We followed the cell out of Hastings and toward the northeast.  Low-level rotation was intense at times, and a small funnel formed and dissipated in a matter of 20 seconds (Photos #3, and #4). But, this cell eventually dissipated 20 minutes later, and our chase was over by 7:30-8 PM.

Additional Pictures can be found at Brian Thalkens homepage.

MAY 5: SOUTHWEST NEBRASKA (Squall-line)

This day held some potential for a few isolated tornadoes in Nebraska, especially to the northeast of a surface low near the Nebraska/Kansas/Colorado border.  Therefore, Steve Peterson, Mike Hollingshead and myself departed towards a target zone between Kearney and North Platte, but a brief stop to check data in Grand Island led us to reposition our target near Holdrege, Nebraska.  Storms began to fire during mid-afternoon from just north of McCook, Nebraska south into Western Kansas.  We intercepted a storm to the north of McCook and followed it towards the north (even though the storm itself was moving northwest, around the 500 mb low).  This storm eventually developed a fantastic back-sheared anvil with a nice updraft tower below near North Platte, but it continued to move north into the Sand Hills (which has a terrible road network), therefore we let it go and headed back east.

We soon learned that the SPC had issued an MD for our region highlighting the possibility of a tornado watch being issued during the next hour or so.  This gave us some inspiration, but a watch was never issued.  We still ended up intercepting a bowing thunderstorm complex, with no particularly interesting features at around 6-6:30 PM, but we decided to head back toward Lincoln 45 minutes later.  On the drive back, we stopped briefly just south of I-80 and observed a nice storm with some LP'ish structure at around sunset (Mike Hollingshead has a few pics of this storm).

MAY 6: SOUTH CENTRAL IOWA (Supercell)

This was one of those chases were you start with very low expectations and go back home completely satisfied, having just observed a long-lived supercell.  My chase partners and I left Lincoln, NE at around 2:45, eastbound on hi-way 2 towards a moisture convergence bullseye in SW Iowa, ahead of a cold front, but along a surface confluence boundary.  Shear was not great but CAPE was starting to approach 2000 J kg-1.  Our target zone was near Mount Ayr, IA.

The day was kind of dragging along as we went through some high based convection (Photo #1).  But by 4:45 PM we spotted an isolated thunderstorm updraft 20-30 miles to our northeast.  We soon observed the updraft taking on a cork-screw appearance and immediately decided to target the storm.  At 5 PM we entered Mount Ayr, IA and headed north on hi-way 169, stopping soon after to get some pics of the storm (Photo #2, #3, #4).  By this time, an inflow band was present near the base of the storm and at the mid-levels of the storm.  The updraft was really wound up at this time also.  The inflow bands then evolved into two separate plates with striations along the plates, encircling the whole southern side of the supercell.  We quickly departed again to get closer to the base.

At 5:30 PM we stopped north of Lorimor as the flanking line cells began to take on a stair-step appearance.  We could also see a hail shaft to the northwest of the intersecting flanking line/main updraft tower, and cloud tags entering the rain free base which eventually resulted in a wall cloud (Photo #5, #6).

Headed further east at 5:50 on county hi-way G68 and stopped north of Truro by 6:20 after by-passing some construction, observing a funnel along the way (Photo #7, #8).  The supercell now developed a rear-flank downdraft with a text-book clear slot wrapping around the updraft base (Photo #9, #10, #11, #12).  Rotation was intense and a funnel developed 10 minutes later...however, no tornado.

We continued to follow the supercell northeast until its updraft filled with rain at around 7...we called off the chase at 7:30.  This was a great chase, we observed everything except a tornado.  The supercell was photogenic for 2 hours and we got great video and pics.

Additional pictures are available at Brian Thalkens web page.

MAY 9: EASTERN NEBRASKA (Squall-line)

Todays initial target was Sioux City, IA, but we ended up chasing a storm much closer to Lincoln, Nebraska, which is always nice.  The chase team today consisted of Angela Oder, Brian Thalken, and myself.  We headed out from Lincoln, NE at around 4, northbound on hi-way 77.  Turkey towers were starting to pop up to our west and northwest, and by the time we reached Fremont, NE, one cell began to mature and dominated the local environment.  We decided to abandon our original target zone, as this cell was displaying some interesting features.  We drove to the top of a hill south of Scribner, NE and waited patiently for the cell to mature some more.

We ended up sitting in the same position for ~ three hours, this cell was anchored to the same location forever (or so it appeared)!  The storm was very entertaining during this time, with vivid anvil crawlers as well as CG's underneath its elevated base.  The mammatus were huge and probably the best I have ever seen.  In addition, the storm began to develop a mid-level inflow band that rotated into the middle-portions of the updraft.  However, the low-level features remained un-impressive, that is until 7 pm rolled around.  At a little after 7, the Omaha NWS issued a radar indicated tornado warning for our cell (Dodge/Cuming Counties until 8 pm).  A rain free base was present, and we could confirm that rotation at the base of the cloud was intensifying quickly after the TOR warning was issued.  However, a wall cloud never really developed and rain curtains tended to disrupt our visibility.  However, we noticed another rain free base 10-20 miles to our west, and soon after the Omaha NWS issued another radar indicated tornado warning.  So we thought we might possibly see two tornadoes on the ground at the same time.  Unfortunatley, no tornadoes or even funnels were produced by these storms.

As sunset rolled around, we finally decided to move south in order to stay away from an approaching rain/hail shaft.  As we entered Fremont, NE another tornado warning was issued for the cell we were next to.  However, this time it was based on a report from the media, claiming that they saw a tornado touchdown.  This was a bogus call by who-ever phoned it in.  We were on this cell for its entire life-time and at no time did a tornado vortex ever come in contact with the ground.

MAY 10: SOUTHWEST IOWA (Supercell)

Todays "chase team" consisted of Chad Kauffman, Brian Thalken, Christy Carlson, and myself.

After completing our analysis of the current atmospheric setup, we all agreed on Glenwood, IA as being a good inital target.  We left Lincoln, NE at around 2:45 pm, eastbound on I-80.  However, we soon noticed that the cap was still pretty strong since the Cu field was stratifying, so we decided to head towards Missouri Valley, IA in hope that the cap would break sooner there.  By the time we got off I-680, northeast of Omaha, there were some holes in the stratus deck which encouraged us to remain north of Omaha.  However, after much consternation, we realized that the cold front had moved through the area so we decided to head back south toward our original target of Glenwood, IA and wait for convective development there.

After a quick jaunt down I-29 south, we sat 3 miles southwest of Glenwood, watching TCU's develop, but then sputter out.  At around 5 pm we noticed an area of sustained convective development 10 miles south of our location and we decided to quickly depart.  We continued heading south on I-29 toward the Nebraska City exit.  By this time, a large, rock hard thunderstorm updraft blew up just to our southwest.  We decided to wait 2 miles east of exit 10 on I-29 and watch this storm's development.  We noticed another large thunderstorm 30-40 miles to our east/southeast and started to wonder whether we should go intercept that one instead.  Chad related a story to me about how Walker Ashley and him had left a storm one time that eventually went tornadic in pursuit of "taller clouds."  (Patience is a virtue!)  We all eventually calmed down and decided to continue waiting on the storm in front of us since it was beginning to take on supercellular characteristics, such as: a powerful updraft blowing up above us and inflow bands flowing into the base of the updraft.  This storm then soon developed a menacing forward flank downdraft.

Twenty minutes later, we observed a hint of a wall cloud developing, with its source of scud developing in the rain cooled air in classic fashion.  In addition, a clear slot started to wedge into the base of the updraft, thus, we decided it was time to head east.  Soon after we hit the road again, we began to observe more and more scud being drawn into the updraft base, with scud originating closer and closer to the ground.  In a matter of 5 minutes, a gigantic wall cloud had developed right before our eyes which was beginning to rotate!  We positioned ourselves 1/2 mile southwest from this wall cloud and set up the tripod, ready for the tornado.  The base of this wall cloud was ~300 feet AGL, and from my perspective, was one of the best wall clouds I have ever seen (given the fact we were so close to it).  Tornado development seemed to be only a matter of minutes.  Then, a rain curtain started to wrap around the wall cloud from the northwest side.  We knew that this rain curtain would probably kill the tornadic potential soon, or else it would be a rain wrapped tornado and thus un-chaseable.  Still, on a side note...since this rain curtain was rotating around the wall cloud, it is not out of the question that a large, broad scale tornadic circulation was in contact with the ground.

We decided to head east to get ahead of the rain.  10-15 minutes later we pulled over and observed that this storm was starting to bow out...however...we saw a new rotation developing along the northeast section of the bow...and...5 minutes later, the Omaha NWS issued a tornado warning for the storm.  We followed this storm east for 20-30 minutes, observing a tight circulation the whole time.  This circulation was so close to the ground, but the rain cooled air probably prevented it from touching down.  10-20 minutes later, we concluded that the rain/outflow finally took over the circulation/updraft.  At around 7:45 pm, we made the decision to head back towards Lincoln.

All-in-all, the most important decision made this day, was to be patient and wait on the original cell just east of the Nebraska City exit.  After Chad examined the radar imagery from our convective event(s), the dramatic cell we had seen developing so clearly to our south and east was actually part of a WAW (warm air wall) ahead of the prefrontal boundary, which quickly dissipated as the linear convective line approached.  We had made the correct decision.

Christy Carlson has some nice pictures from today's chase posted at her websight.

MAY 20: SOUTHEAST OKLAHOMA (Supercell)

I finally experienced true "chaser convergence" on Sunday, May 20, just outside of McAlester, Oklahoma.  This was to be expected though considering the atmospheric setup for this day in the Southern Plains (100 kt upper-level jet streak coupled with a very unstable atmosphere).

Two friends of mine and I took off from Lincoln at 2:30 am on Sunday and arrived in Norman, OK at around 10 am to use the OU computer lab and get some updated data.  Pauls Valley, OK still looked like a good target for initiation and we headed south out of Norman on I-35 at around noon.  As we pulled onto I-35 we ended up right behind Nebraska storm chaser Steve Peterson and his wife, so I gave him a quick call on the cell phone and we agreed to meet up in Pauls Valley.  At around 1 pm, we found a nice ridge-top on highway 29, southwest of Pauls Valley, and we waited for initiation...we waited several hours (I have a nice sunburn).  

A tornado watch was issued at 3 pm for most of Eastern Oklahoma as turkey towers attempted to break through the cap.  We noticed one dominant cell to our northeast which soon developed an anvil, but we let it go.  This storm ended up producing multiple tornadoes in McIntosh and Hughes Counties, Oklahoma...oh well.  Two or three supercells rapidly developed to our north and south by 4 pm.  We moved east with these storms.  They had fantastic updrafts, and the southern sup was very photogenic with clear blue skies behind it, a great tower, and a terrific anvil.  However, we decided to intercept the northern storm as it looked more intense and we could see its rain free base.  It developed a nice wall cloud as we entered Ada, OK.  Thirty minutes later, the wall cloud developed an intense circulation with a rear flank downdraft clearly wrapping into the southern flank of the low-level mesocyclone...it was very close to producing a tornado, but couldn't quite do it.  We continued to follow the storm into McAlester, OK with a million other chasers (including the DOW).  I decided to let the storm go at McAlester (time was ~7 pm) but I believe Steve continued to follow it.  Later that evening, other chasers including Steve reported power flashes under the base of our supercell, so it may have produced a TOR.

Overall, it was a good chase.  The storm structure was great, and the low-level features had us all very excited at times.  However, the hills and trees of Eastern Oklahoma make chasing very hard there.

MAY 26: TEXAS PANHANDLE (Supercell)

Steve Peterson and I departed for Dodge City, KS on May 25 in order to be in position for a northwest flow severe weather event in the Texas Panhandle on May 26.  On the morning of May 26, we stopped by the Dodge City, KS NWS office in order to get some current surface and upper air data as well as the latest SPC convective outlook.  Things still looked a bit ambiguous and we couldn't narrow down the most favorable location for convective initiation.  The dryline appeared like it would be diffuse and inactive during the day, and I believed storms could fire up anywhere from Amarillo to Shamrock to Lubbock.  So we decided on Childress, TX as an initial target zone and then narrow down our options from there.

We took highway 83 south through the Eastern Texas Panhandle and arrived in Childress during the early afternoon.  After making a few phone calls in order to get some updated information, we decided to head further west toward Turkey, TX and wait for initiation along the breaks of the Caprock.  By 4 pm, the SPC issued an MD for much of the Panhandle, with the western edge of the MD west of a line from Amarillo to Lubbock.  We decided to head further west to I-27 in order to catch the initial cells of the day.  However, at 4:50 pm we entered Silverton, TX, and just to our south a cell was beginning to break through the cap.  We gassed up and decided to head south down highway 207 and parallel this developing cell.  We stopped at 5:30 pm (tornado watch was issued for the area shortly after) in order to better observe our cell.  It had a nice rain free base and the updraft was decent, but it was elevated and struggling to really get organized.  We could also see another severe thunderstorm to our southwest near the Lubbock area, which supposedly produced a tornado.

We stuck to our original cell during the remainder of the day.  As we did so, we ended up behind the UMASS DOW as well as Howie Bluestein's mm radar truck.  We also met up with former UNL meteorology grad student Walker Ashley as well as Nebraska storm chaser Mike Hollingshead.  To summarize, our cell eventually fell apart just before sunset, and a large MCC organized to our south, which we let move away from us.

Mike Hollingshead has a few pics from his chase on his websight.

MAY 27: SOUTHWEST KANSAS (Derecho)

Today Steve Peterson and I teamed up with UGA grad student Walker Ashley and his three friends, as well as Nebraska storm chaser Mike Hollingshead.  After a rather brief morning analysis in the Camelot hotel in Amarillo, TX, we all eventually came to an agreement that Ulysses, KS would be our target city.  

After checking the current surface data, satellite, radar, and a few other parameters in Ulysses, we agreed that it would probably be necessary to head further north; mainly because convection was developing near Goodland, KS.  The Goodland storm became tornadic by 3 pm and the SPC issued a severe thunderstorm watch by 3:30 pm.  We arrived in Garden City, KS shortly after the watch was issued and observed three distinct cells just to our north via TV radar out of Wichita, KS.  These cells were quickly congealing and appeared they would be outflow dominant soon.  So we decided to head northwest toward another cell propagating southward, which had a history of producing tornadoes.  As we reached this cell, we observed a beautifully striated updraft with a nice occlusion occurring to the northeast of the main tower.  However, we also observed the rapidly expanding shelf cloud and the large amount of dust being kicked up.  We let this shelf cloud approach us, got some pictures, and then headed south once the dust began to approach our location.  However, Mike stayed behind and experienced the brunt of this storms outflow.  By this time, everything was outflow dominant, with new, discrete cells forming many miles to our south.  We couldn't reach these new storms, so our chase was over by late afternoon.

Mike Hollingshead has a few pics of this chase on his websight. 

JUNE 1: SOUTHCENTRAL KANSAS (Supercells)

I observed three supercells in KS today, one which had a tornado warning on it for two hours. I left Lincoln at 11:30 am with Salina, KS as my initial target zone. 

As I was driving south down highway 81 in Northern KS, a t- storm watch was issued for Southern NEB and Northern KS, and in fact, I could see a line of storms in my rear-view mirror. I ignored these storms, knowing that moisture was rather shallow in NEB, and surface winds were veered from the west. So on to Salina, were I hoped surface based sups, and at least a slight shot at a tornado existed. 

As I pulled into a gas station just north of Salina at around 3 pm, I noticed a few interesting TCU's just to my south. I got gas and some food, and when I came out of the station, these TCU's had exploded (some of the most explosive convection I have seen). I immediatley got back onto I-135 and headed south toward a rapidly developing thunderstorm (time was 3:10). At 3:20 pm, I learned that the SPC had just issued a TOR watch for all of Central KS. I was somewhat expecting a TOR watch given the explosive cell in front of me, and the rapidly evolving low-level features (rain free base, developing wall cloud...). I got off I-135 just north of McPherson, KS and followed the sup from behind (north west flow events are not fun patterns to chase). At 3:50 pm, the Wichita NWS issued the first of many TOR warnings for this storm. I continued to follow the storm for the next 1 1/2 hours, ending up east of Newton, KS by 6 pm. TOR warnings were issued for this cell the whole time, however, I noticed several things which might have caused tornadogenesis failure. One was that even though the mid-level meso and low-level meso were quite impressive, they never seemed to be collocated quite right. Another was that the atmosphere appeared to be worked over quite a bit by convection, which may have resulted in "tainted" inflow/weaker low-level buoyant instability. I gave up on the Newton supercell as it appeared to rapidly disipate by 6, and got two more sups near Hutchinson, KS, each with impressive low-level mesocyclones. These cells were nice, but not quite as exciting as the first storm of the day. I ended the chase by 8 pm, just west of Wichita, KS.

JUNE 4: CENTRAL KANSAS (Supercell)

Christy Carlson and I caught a beautiful supercell to the north/northeast of Newton, KS today. We left LNK at 1:45 pm with a target around Herington, KS (which is southeast of Salina). We moved a bit west of this location to get closer to the area of maximum convergence, and by 5:40 towers began to pop up. One cell matured by 6:50 near our location and we followed it for a while (tornado watch was then issued at 7pm). This cell soon died, but we could see another one to the south, and by 7:20 we were racing south down hi-way 56/77. The back edge of this storm was very nice, with a solid updraft tower and back-sheared anvil. 

Shortly after 8, we reached the base and slowly made our way east on some very muddy roads in order to get to the eastern side. Once we got to the other side, we quickly noticed the beautiful anvil spreading northeast above a sculpted updraft. Inflow bands were feeding into the southern flank of the updraft, and a beavers tail had formed on the northeast flank. By this time (8:40), we positioned ourselves about three miles northeast of the base on hi-way 50. The whole thing was rotating in harmony. Then a clear slot started wraping into the northern half of the base, and low-level rotation quickly strengthened. We watched the storm for the next 30 minutes, but nothing of interest developed (sun was down by this time and low-levels were probably stabilizing quickly). We ended the chase at ~ 9:30.

Christy Carlson has a few pics of this storm posted at her websight.

JUNE 7: NORTHEAST COLORADO

Chris Bowman and I targeted Northeast Colorado.  The day ended up being a bust...the details are to painful to share.

JUNE 12: SOUTHEAST SOUTH DAKOTA (Supercell)

The setup today appeared to have decent potential for the development of tornadic supercells from the Central Plains into the High Plains.  However, the challenge was to find where the cap would weaken sufficiently for convective initiation.  Brian Thalken, Christy Carlson, and I left Lincoln, NE at around 2 pm with O'Neill, NE as our target city.

We arrived in O'Neill at ~ 5:30 pm, with an MD being issued by the SPC about an hour earlier highlighting the potential for supercells in Northern Nebraska and Southern South Dakota.  At ~ 7, we saw several un-impressive cells develop to the east and northeast of O'Neill.  After a little debate on which area to target, we decided to race north/northeast into SD.  This was a good decision, as the northern cell developed a strong updraft.  In addition, a tornado watch was issued for Southeast SD as we were in pursuit of the northern cell.

By 7:50, we finally caught up with what was now a supercell in Hutchinson County, SD.  The base showed some rotation, and a clear slot began to cut into the low-level meso.  A tornado warning was then issued for our cell at ~ 8 pm.  We drove east out ahead of the supercell in order to gain better contrast.  This cell had tornado warnings on it until sunset...however, no tornadoes were produced.  The mid-level features were spectacular though.  A flanged base developed with inflow bands wrapping into the updraft, and the mid-level mesocyclone had extremely strong rotation.  In the end, we did witness several gustnadoes just after the sun set.

JUNE 13: EASTERN NEBRASKA (Supercells)

Everything looked great today for a widespread outbreak of severe thunderstorms from KS north into MN.  A cold front was slowly advancing eastward through the Northern and Central Plains.  The warm sector was moist and unstable with CAPE's rising to 3000 J kg-1or greater.  A strong upper-level jet was coupled with a moderate low-level jet which resulted in favorable deep layer shear for supercells.  I decided on a target just north of Fremont, NE, which was an area experiencing strong moisture convergence.  I took my sister along on this chase, and we left at around 2 pm.

By 4:40, turkey towers were starting to pop up to the west of our target.  We headed a bit east to US-77.  At 6 pm, a tornado watch was issued for all of Eastern Nebraska, and at 6:30 pm, several supercells had developed to our northwest, west, and southwest.  We were now in the town of Scribner and debating on which supercell to intercept.  Just after 6:30, a tornado warning was issued for Cuming and Stanton Counties (which were the counties just to our north).  We drove north on US-275 and intercepted the base of this tornado warned supercell.  A large wall cloud developed at 6:40 as we were entering Cuming County.  This wall cloud developed into a large, cone shaped funnel, but didn't touch down (at least from our vantage point).  At 7 pm, another tornado warning was issued for Cuming County, and we continued to watch the storm of interest.  And at 7:10, another large wall cloud developed which was very low to the ground.  At 7:30, we gave up on our current storm and headed south of West Point.  At 7:37, a tornado warning was issued for the storm we were on south of West Point.  Scud was rapidly rising into the developing wall cloud and the rotation in the low-level meso was quite obvious.  But, by 8 pm, this storm started to dissipate.

It was at this time that we heard reports of a large tornado on the ground near Seward, Nebraska.  My heart sunk, as I knew there was no way we could get to that supercell (it was an hour away).  But, we decided to race south down US-77 and see if we could catch any additional tornadic development.  We got to the storm as it was entering Wahoo, NE.  By this time it was outflow dominant, and no longer a tornado threat.  If I would have stayed in Lincoln and watched the situation un-fold, I would have mostly likely caught the very photogenic tornado near Seward.  Congrats to all the other chasers (e.g., Brian Thalken, Steve Peterson, Matt Sherman, etc., etc. for their catch).

Brian Thalken and Steve Peterson both caught the Seward, NE tornado, and have made their pictures available at the provided links.

JULY 3: SOUTHWEST IOWA, NORTHERN MISSOURI (Squall-line)

Christy Carlson and I had a moderately successful chase in IA/MO today (at least we didn't bust). Todays setup featured a very moist and unstable atmosphere and decent directional shear. However, deep layer shear was marginal (0-6 km was ~35 kts/BRNSHR less than 40 m2 s-2), and suggested HP supercells at best. Still, we decided that intense convection was likely in SW Iowa ahead of an area of strong moisture convergence, just to the east of the MO river. So we left LNK at around 3. 

We passed Neb City at 3:45 and stopped for food at a gas station near I-29 in Iowa. While we were paying for the food, we saw on a TV that a tornado watch had just been issued for our target until 10 pm (kind of surprised). So we headed further east into the watch box, observing a large thunderstorm to our east in Ringgold County. We decided not to pursue this storm since other TCU's were building around us at the time (RUC indicated that the best shear/CAPE/convg. combination would be located in SW IA/NW MO). After waiting for about an hour near Bedford, IA, a new intense updraft developed at 5:45 a few miles to our east, with another developing storm to our north and west. We positioned ourselves in-between all three storms, ready for one to become dominant, and hopefully tornadic. However, by 6:30, it became obvious that all three storms were becoming increasingly outflow dominant, with little potential for tornadoes. We followed one cell toward the southeast into MO which exhibited bowing characteristics. By the time we got to Bethany, MO, we knew it was time to call off the chase (just wind and hail). On the drive back to Lincoln, we came upon a more discrete cell (8:20 pm). This cell had some nice structure for awhile, with a nice laminar base.

PICTURE 1: BACKSHEARED ANVIL; PICTURE 2: INFLOW INTO THE BASE OF A DEVELOPING STORM; PICTURE 3: STRIATIONS/LAMINAR BASE; PICTURE 4: STRIATIONS/LAMINAR BASE

JULY 16: NORTHEAST NEBRASKA (Supercell)

Christy Carlson and I left LNK at ~3 PM today, with a target anywhere north of Grand Island, NE. We knew a cell had already initiated in extreme Northcentral NE, and we were expecting more development toward the south along a surface trough. By 3:30, we heard that the northern storm (in Rock County, NE, which we could see from York, NE) had gone severe, so we decided to head toward that area and turned north onto hiway 81 (SPC issued a SVR T-storm watch at about this time valid till 10).  It was also around this time that I decided to check and make sure my camera was working, and I found out the battery went dead, so I had to use a disposable camera (so no pics available from todays chase until later). 

As we entered Albion, NE, the storm we were heading toward was simply huge!...it was a monster. The updraft was rock hard, the anvil was awesome, and it was totally isolated.  Svr t-storm warnings continued to be issued for it the whole time we made the drive north. At 5:15, we reached Elgin, and decided to go west on hiway 70 just in-case the supercell took a hard right turn. We then went north on a county road through the sandhills.  As we were approaching Ewing, we could now observe the base...and minutes later a tornado warning was issued for the storm (~6 PM) for Holt County.  We positioned ourselves 2 miles south of the base.  Mid-level rotation was great, and inflow bands made for good pictures.  Then, a wall cloud developed a mile or so to our north...but 10-20 minutes later, we felt a cool north breeze and got that sick feeling when you know a storm is so close, but then it develops a strong cold pool.  It went outflow dominant quickly, but the tornado warning was extended.  We headed south, stoping here and there to get some nice structure shots (nice striated shelf cloud). 

Christy Carlson has some nice pics of the storm observed on this day.