2002 STORM CHASE ACCOUNTS

MARCH 19: CENTRAL TEXAS (Several Tornado Warned Cells)

Today's chase started at 10am as I left Gatesville, Texas, heading toward my target of Eden, Texas (east of San Angelo, TX).  By 2pm I was approaching Menard, TX when I started hearing reports of strong thunderstorms over the radio near San Angelo (which was to my northwest).  Then at 2:10 pm, a tornado warning was issued for Tom Green County, so I raced north on highway 83 in order to intercept the storm.  By 2:30 I was north of Eden, but I was unable to catch up to the tornado warned cell, so I watched from a distance as it moved to the northeast.  Storm-structure was non-existent on this cell due to the strat-deck (definitely not worth a picture).  I waited an hour, hoping redevelopment would occur somewhere in the area, and at ~3:45pm, another tornado warning was issued for a cell exiting Sutton County (which was to my southwest).  I knew that if I could get to Menard, TX in time, then I could intercept this cell perfectly (it was moving northeast along highway 190).  I reached the base of the storm at 3:50pm, and observed CG's in every direction.  The cloud base was extremely low and very agitated.  However, this cell failed to produce a tornado.  By 4:15pm, the cell appeared to bow-out rapidly, and very strong straight line winds caught up to me (possibly a wet-microburst).  I waited out the storm in Menard, and decided to end the chase there (driving was impossible due to the heavy rain).

APRIL 7: NORTH CENTRAL TEXAS (Large Tornado/Supercell)

Brian Thalken and I decided to take a chance on what appeared to be a fairly potent set-up in Texas, with the potential for dryline thunderstorms developing underneath a westerly upper-level jet streak.  However, the dryline pattern didn't quite set-up the way we expected on Sunday, which we realized after analyzing an hours worth of data Sunday morning in a University of Oklahoma computer lab.  Needless to say, the results of this chase were outstanding as we turned our attention to a baroclinic boundary in North Central Texas. 

After our data analysis, we headed southwest down the H. E. Bailey Turnpike, with lots of drizzle and low-level cloudiness present.  Our initial target was the Abilene, Texas area, however, as soon as we got an hour south of Wichita Falls, Texas, the skies cleared with temps in the mid to upper 70s, turkey towers developing to our east, and a line of storms developing off to our southwest.  We passed the DOW team, and then parked a few miles south of them so that we could get an update from our nowcaster back in Lincoln, NE.  The storms to the west appeared to be lining up from a radar viewpoint, so we decided to pursue the towers to our east.  After we got gas in Haskell, TX, we went east on highway 380 towards Throckmorton, TX.  We stopped every so often to get pictures of the developing convection building around us, but nothing too spectacular was going on.  However, we did notice a thin line of whispy scud just to our south, which I thought might have been the southern edge of a boundary.

Just before 3 pm, we called in to Lincoln for another update, and our friend Dave Radel (who did a great job nowcasting) described what the cells to our west were doing.  These cells were strong with a few T-storm warnings being issued for one in Haskell County, but they still didn't look too organized.  But, it was the only thing going on around us, so we went west in order to investigate.  Just after 3 pm, a severe thunderstorm warning was issued for a cell in Throckmorton County, (this cell was just a few miles to our west).  We noticed what appeared to be a shelf cloud produced by outflow, and I thought that the show was over and things would line up quickly.  However, this low-level feature began to fill in, and took on the appearance of a developing wall cloud.  So we parked on top of a hill with a great view over a valley at 3:04 pm (our position was 8 miles west of Throckmorton, TX), and set up the tri-pod/video equipment (we were about 2-3 miles east of the storm).  During the next 30 minutes, we watched the rain-free base evolve, organize, and develop a broad-scale rotation (the mid-level rotation was a bit more obvious).  This rain-free base was very well defined, and scud was being sucked in from the forward-flank downdraft.  The surface winds were due east (enhanced low-level shear due to the boundary or just good old fashion inflow), and by 3:20 pm, the low-level rotation really got its act together.

By 3:28, a well defined, very low wall cloud formed, with scud rapidly ascending into the base.  At 3:29 pm, we heard over our radio that the National Weather Service issued a tornado warning for this cell, and at 3:31 pm, the first condensation funnel formed and connected with the surface.  A few vortices danced around the wall cloud, but no dominant funnel was present.  

During the next 5 minutes, the developing tornado moved northeast across the highway and into an open field.  Then, a larger, more well defined condensation cloud developed, and the tornado began to mature/grow larger.  The clear slot was spectacular, and a collar cloud was present around the tornado cyclone, bulging out away from the center of rotation (it appeared to be associated with the clear-slot).  After 10 minutes or so, the tornado grew much larger and began to take on wedge size proportions.  It was at this point that we began to hear the tornado as it moved almost parallel to the highway we were on (we were only 1/2 mile from this tornado).  The sound was something like rushing water, or a wind gust moving through a tree and blowing its leaves.  

The RFD continued to advance east and eventually reached our location.  It was a very warm RFD, maybe even slightly warmer than the storms inflow (e.g., Markowski et al., VORTEX results).  The tornado continued to move east-northeast until we were eventually southwest of it.  A few minutes later, it went into its rope stage and then dissipated soon after (the tornado lasted at least 19 minutes, from 3:31 pm to 3:50 pm).  Another large funnel was present to the north of the old one, but it didn't manage to develop any further.

In my short chasing career, this tornado was one of the top events I have observed so far.  In addition, some of the findings coming out of VORTEX during the last few years seemed to fit in well with this event.  There was a baroclinic boundary, a persistent updraft (the supercell which moved north over the boundary), and a warm RFD.  But besides the educational benefits of this chase, I think I can summarize by saying that this was simply a beautiful, very photogenic, intense tornado.

Brian Thalken has some great pictures of this storm here...also, check out Chuck Doswell's account here.

APRIL 13: EASTERN TEXAS PANHANDLE (Bust)

BUST!...I chased with a couple of friends in the Texas Panhandle today, targeting a few convective outflow boundaries ahead of a surface trough.  We ended up somewhere southwest of Childress, TX, watching mushy looking convection try to become organized.  One cell had a decent updraft, but overall it wasn't much to look at.  It was a good learning experience though, don't drive hundreds of miles to chase a potential severe weather event based on conditional mesoscale processes in an otherwise weak synoptic pattern.

APRIL 16: SOUTHEAST NEBRASKA (Squall-line)

Brian Thalken, Jim Kaiser, Jason Ehmke, and I targeted a cell about an hour or so southwest of Lincoln, NE.  This day appeared to have decent potential based on our morning analysis.  However, our area didn't receive much clearing during the day, and the dewpoint depressions were fairly large.  Still, low-level shear was pretty strong, so we believed that any cell forming on the southern end of what was sure to be a squall line from MN south into NE might do something interesting.  However, we were wrong.  We did get the southern-most cell, but it was pretty un-impressive.  So we followed it back to Lincoln, and ended the chase just before sun-set.

APRIL 27: SOUTHEAST NEBRASKA/SOUTHWEST IOWA (Mini-supercells)

Todays chase focused around a deep surface low forming ahead of a progressive short-wave trough.  Jim Kaiser, Brian Thalken, and I made it to our target (Fairbury, NE) by 1:30 pm with a clear-slot just beginning to move over the region, and we immediately observed towering cumulus to our west and southwest.  These towers rapidly advanced east/northeast along an occluded front/dryline, so we quickly moved east toward Beatrice.  After we got gas in Beatrice we continued east, and shortly there-after a tornadic cell developed in Lancaster County, Nebraska (~3:15 pm).  We were too far to the southeast to try and catch it (from my experience, tornadic mini-supercells usually don't persist for a long-time).  So, we continued east and crossed into Iowa on highway 2 at 3:50 pm, hoping to possibly intercept a few cells moving east/northeast through northeast Missouri. 

By 5 pm, new development occurred in southwest Iowa, with one cell producing a tornado along I-29 (which we did not witness).  We followed a cluster of mini-supercells northeast, and observed one of these cells go through a vigorous occlusion, which was spectacular to watch.  Several tornado warnings were issued for a couple of cells to our east, and we followed these toward Des Moines, however, they never produced.  From a forecasting perspective, today was a good learning experience.  Apparently, relatively-high theta-e values were able to advect north along a narrow path just ahead of the advancing occluded front and then wrap back around toward the surface low.  The resulting instability allowed for surface based storms to develop right along the frontal boundary, and a few of these produced tornadoes.  Instability immediately to the east/northeast of the front was almost non-exsistent, and therefore the cells which formed along the front could not persist when they moved away from the theta-e axis.  I'm looking forward to "less-dynamic" systems during May and June.

MAY 5: NORTH CENTRAL KANSAS (Tornado/Supercell)

Brian Thalken and I decided to target an area around Red Cloud, Nebraska.  We left Lincoln, NE at 12:40 pm, headed west to Grand Island, and then south down highway 281 towards Red Cloud.  As we entered Hastings, I decided to get some lunch, and we called our friend Steve Peterson (who was chasing the same general area).  We met up with him, and learned of a tornado watch being issued for Central Kansas.  We decided to continue heading south toward Red Cloud and catch convective initiation in North Central Kansas.  As we were approaching Red Cloud, we could see a large thunderstorm with a great anvil to our southwest.  By 4 pm, severe thunderstorm warnings were being issued for numerous cells in North Central Kansas.  So we headed south a bit more, and parked a few miles south of the KS/NE border. 

At ~4:15-4:30 pm, we were about 5 miles to the northeast of an intensifying cell in Smith County Kansas.  The forward flank downdraft was effectively blocking our view of the base.  In addition, intense CG action was occurring all around us, which meant we had to spend more time in our vehicles than outside.  At 4:50 pm, a tornado warning was issued for our cell, but the base was still being obscured by the FFD rain core (this cell was not moving in a typical fashion).  So Steve and his wife headed a bit south to get out of the rain.  Brian and I eventually did the same, and by ~5 pm, we parked on top of a hill and observed a very intense mid and low-level mesocyclone to our west/northwest.  By 5:20, a decent funnel formed, followed by an eventual tornado.  This tornado was initially shaped like a small elephant trunk, but soon took on an assortment of contorted shapes.  This tornado lasted about 5 minutes.  After it dissipated, a new low-level mesocyclone developed to the north of the old one, and a giant wall cloud soon followed.  This wall cloud was below a great rotating updraft with a decent inflow tail entering the eastern flank of the storm.  The wall cloud began to occlude as the storm slowly moved east over highway 281.  Brain and I then felt cold outflow, which was obviously a negative factor to additional tornadogenesis.  However, we were pretty satisfied with the events preceding the demise of this supercell, and decided to head back to Lincoln at 6 pm.

MAY 6: CENTRAL KANSAS (Multi-cells/Evening LP Storm)

Brian Thalken and I left Lincoln, NE at 1:30 pm, and our target for today was Salina, KS.  As we approached Salina from the north (at ~ 4:15 pm), we saw a large tower erupt to our south.  So we quickly got gas, and then headed south toward McPherson, KS on I-135.  From the beginning this storm displayed multi-cellular characteristics, as one updraft would mature, then dissipate as a new cell would initiate on the rear-flank (the shear profile supported this type of convective mode, e.g., straight hodographs with weak low-level shear).  So we went east from McPherson and watched this multi-cell (which went through numerous splits) head off to the northeast.  Mean-while, other storms developed back toward the southwest.  We headed west to investigate, and actually observed what was a weak tower initially, eventually mature into a gorgeous thunderstorm with LP'ish characteristics as the sun-set (some of my best pictures of the year are of this storm).  The base was long and dark and the updraft was a crisp blue-ish white, with red and orange colors back-dropped on the horizon.  A nice mid-level funnel even formed and persisted for about five minutes....good way to end the chase.

MAY 11: NORTHEAST KANSAS (Squall-line)

Original target for today was Salina, KS.  However, as Brian Thalken and I were entering Kansas on highway 81 (at 2:15 pm), low cloudiness cleared out and we immediately observed large towers building over us and to our southwest.  So we got gas, and by 2:45 pm, we were following an intensifying cell southeast of Chester, Nebraska.  This storm continued to strengthen and was also displaying signs of mid-level updraft rotation.  By 3:05, large amounts of scud were being sucked up into the updraft base.  Unfortunately, a cold front was also moving southeast through the region, and this cold front caught up to our storm just as the low-level features were starting to get interesting.  So....everything basically lined up, and Brian and I quickly found a south highway in order to catch more discrete activity near Salina.  As we headed south, numerous reports of tornado sightings were being relayed over the radio station we were listening too.  At 5:10 pm, we finally reached I-70 near Abilene, KS, and we headed west in order to intercept a tornado warned cell in Saline County.  By the time we reached this cell, it appeared to have bowed out, with a solid precip core falling through the center of the updraft, and a hint of a bookend vortex on the northern portion of the updraft.  Nothing became of this storm, and we ended the chase soon after.

MAY 22: SOUTHCENTRAL NEBRASKA (Squall-line)

My target for today was Red Cloud, NE.  As I approached Fairfield, NE (southeast of Hastings) at 4 pm, towering Cu's were building ten miles west, so I blew-off the Red Cloud target and watched these towers evolve, mature, and produce unimpressive, mushy anvils.  By 5:40 pm, I moved toward Edgar, NE with one cell to my southwest and another to my northwest.  I kept my position and monitored both cells until the northwest one began to develop a wall cloud.  In addition, it was displaying some signs of mid-level rotation, with a few inflow bands present.  So I headed a few miles northwest, but this cell began to bow out fairly quickly, with a big precip core developing behind the updraft base by 6 pm.  By 6:30, a solid line of convection was present from north to south, so I decided to call it a day and head back to Lincoln.

MAY 23: SOUTHCENTRAL KANSAS / NORTHCENTRAL OKLAHOMA

BUST...an uneventful chase day for me.

JUNE 2: NORTHEAST NEBRASKA

BUST...potential was there for a few tornadic supercells, however, the cap has to break first.

JUNE 7: NORTHEAST NEBRASKA (Brief supercell)

Left the Omaha area by 12 pm today and headed northwest toward my target of O'Neill, Nebraska.  By 2 pm I was northwest of West Point, NE and could see a large anvil toward the north in South Dakota and a few elevated Cu's off to the northwest.  (Sunshine was abundant today, and my left arm paid the price...)  By the time I arrived in Neligh, NE (~ 3:45 pm), I learned of a t-storm warning for Boyd County, Nebraska.  So I made my way north and intercepted this cell.  The severe cell wasn't too impressive, but a flanking line cell intensified and developed some mid-level rotation...there were even a few fingers of inflow being sucked in.  This convection weakened a bit as it moved east/northeast...so I went back south and became aware of additional severe thunderstorms to my west.  I decided to pursue the closest cell, which was in Holt County, Nebraska.  As I was approaching this cell, I immediately observed a long inflow band extending 15 miles away from the base of the storm...I was pretty impressed.  At 5:45 pm, I parked 5-10 miles east of the updraft base, and was entertained by vivid lightning flashing around the strengthening updraft.  Within 10 minutes, striations developed along the updraft, and the rain-free base began to widen.  This storm was starting to rotate pretty hard, and I was actually beginning to think that it was going to produce a tornado, but then reality set in, which was that this storm was working with a pretty dry boundary layer (large surface dewpoint depressions)...a precip core developed within close proximity to the updraft, and outflow killed the cell.

JUNE 10: SOUTHCENTRAL NEBRASKA (Nice Supercell/Weak Vortices)

Brian Thalken, Jason Ehmke and I observed a beautiful supercell today, as well as two brief, weak spin-ups.  We left Lincoln, NE at 3 pm with a target near Grand Island, NE.  After waiting an hour or so near Grand Island, two large towers erupted to our southwest at 5:50 pm.  We made our way south down highway 281, and positioned ourselves directly to the east of the northern most tower near Ayr, NE.  The northern storm slowly matured, developing a nice anvil, but its updraft was having a hard time strengthening.  Meanwhile, a cell to our south contained explosive convection on its rear flank, but it was behaving like a multicell storm.  So we stayed put, and monitored both storms as they slowly drifted east/northeast.

By 7:50 pm, the northern storm (now near Hastings, NE) was becoming more organized, and featured a bowl shaped rain-free base.  The southern storm was still a strong multicell, so we headed east in between both storms on highway 74.  At 8 pm, we decided to stop on a county road to take pictures (near Glenvil, NE), when all of a sudden a tight funnel dropped out of the northern storm, extending about 1/4-th of the way to the ground...then, 30-seconds later, the Hastings NWS issued a tornado warning for the cell.  This cell was now taking on classical supercellular features.  The anvil was amazing, strong inflow was present at cloud base, the updraft was very strong, and the rain-free base was widening.  We blew off the southern storm and went north down several county roads, and by 8:10-8:15 pm, we finally caught up to the updraft base and parked 2 miles northeast of Inland, NE.  The mid-level mesocyclone was very strong and quite obvious.  In addition, a clear slot could be observed wrapping around the base of the storm. 

At 8:23, a weak vortex was observed.  It was an almost translucent tube of rotating dust extending up to a small area of rotation at cloud base.  This weak spin-up occurred at the point were the clear slot was "slicing" into the base of the updraft.  We then repositioned ourselves, and observed a second, more defined circulation at around 8:30-8:35 pm.  This second vortex was a dusty bowl, and again, appeared to be associated with the clear slot.  By 8:40 pm, we stopped again, and watched a second mid-level mesocyclone develop along the flanking line of the first supercell (Clay County, NE).  This second mesocyclone was very vigorous and the color of the updraft turned gold as the sun-set.  In addition, the storm was strong enough to create 30+ mph inflow winds.  We ended the chase at 9:20 pm watching a beautiful display of lightning.

JUNE 11: CENTRAL KANSAS (HP Supercell)

Brian Thalken, Jason Ehmke, and I targeted an area between Concordia and Salina, KS today.  We left Lincoln at 2:15 pm and arrived in Concordia by 4:30 pm, with a large storm present to our southwest.  It was very dark and ominous as we approached it from the north.  As 5 pm rolled around, we parked on top of a hill south of Trescott, KS (in Ottawa County, KS), and had a great view of this storms wall cloud (on the southern edge of the storm, 15 miles to our southwest), and a dark rain core to the north of the updraft.  Numerous bands of inflow were streaming into the mid-levels of the storm, and the anvil was quite expansive, spreading out far to our east.  At 5:25 pm, a large plume of dust was kicked up underneath the wall cloud.  We can't say whether this was a tornado or not, we were too far away to decipher, however, we could clearly see the wall cloud rotating (it went through several cycles of strong rotation).  By 5:40 pm, it was becoming obvious that this storm was taking a hard right turn toward the southeast and was quickly  transitioning into an HP supercell, so we navigated our way south, skirting by Salina. 

After we moved south of Salina and out of the edge of the storms precip core, we observed just what a monster this thing had turned into.  We were 3 miles east of what was a gigantic wall cloud (incredibly dark, and very menacing).  It was huge, towering high above us, with large inflow bands above our head...it was almost as if the mid-level and low-level mesocyclone had become one entity.  In addition to the storm structure, the lightning was incredible as well.  CG's were shooting out of the base of the storm, as well as the anvil.  In fact, one bolt struck a hill about a mile or two to our west, and it ignited a grass fire.

We entered Lindsborg, KS at 6:30 pm, and began hearing reports over our radio of 70-100 mph straight-line winds associated with this storm.  It was becoming quite obvious that the storm was turning into a bow echo.  We could see the apex of the bow about 10 miles to our south, and a potential book-end vortex right behind us (a few miles to our west) as we moved quickly to the east into Marion County, KS.  It was becoming very hard to stay ahead of the rapidly moving storm complex, and by 7:30 pm, we decided to give up and head back north.  As we began the trip home and the developing MCS moved off to the east, we got a chance to observe a great sunset which back-lit the expansive back-sheared anvil, which contained some very photogenic mammatus.

JUNE 12: SOUTHCENTRAL KANSAS / NORTHCENTRAL OKLAHOMA (Outflow-dominant Convection/Wall Cloud at Sunset)

Brian Thalken and I made it to our target near Pratt, Kansas by 4:45 pm, and observed what appeared to be a monster cell to our southwest near the Oklahoma/Kansas border.  So we went south toward Kiowa, KS, and were anticipating an intense updraft on the southern side of the cell.  However, when we entered Oklahoma at 5:45, the updraft base was elevated and the cell was outflow dominant.  We stopped to get a few pictures near Cherokee, OK, but it was obvious that this cell had little potential besides producing strong outflow.  So we went east into Grant County, Oklahoma and made it to Lamont, Oklahoma in time to see a new cell rapidly intensify (~ 7:40 pm).  This cell had a blocky wall cloud, with a rear-flank precip core to the west of the updraft, and possibly a clear slot.  Within 10-minutes the wall cloud began sucking in large amounts of scud from the east, and the rain-free base widened quite a bit (we were less than a mile from this wall cloud).  However, a strong outflow boundary produced from a storm off to the east made it to our location, and ruined any tornadic potential this cell might of had.  So we basically ended the chase in Lamont and went back north into Kansas on I-35.  As we approached the KS/OK border again, we stopped to get a few pictures of a tremendous display of lightning and mammatus underneath an expansive back-sheared anvil.

JULY 9: SOUTHEAST SOUTH DAKOTA (Non-Severe Thunderstorms)

I made it to Mitchell, SD (my target) by 3:30 pm today, and basically sat around for the next two hours watching a CU field evolve and then finally produce a couple of towers.  A few isolated storms developed by 6:45 pm, and these were interesting, but then their updrafts glaciated and the storms never intensified any further.  So...I began making my way back home an hour before sunset, taking a few pictures here and there of the local wild-life.

JULY 24: SOUTHEAST SOUTH DAKOTA (Supercell)

Brian Thalken, Jim Kaiser and I made it up to Sioux Falls, SD by 2:30 pm today, and then made our way west toward Mitchell, SD.  At around 3, we drove 10 miles south to investigate several large cells developing along the SD/NE border.  We decided not to pursue these and instead decided to target another cell northwest of our location (a few of the cells south of us went on to become fairly impressive supercells later in the evening in Nebraska).  By 5:45pm we were closing in on the cell which was located in Jerauld County, SD (northwest of Mitchell).  A large mid-level inflow shelf was present streaming into the updraft, with a large, white, expansive anvil towering above the updraft.  We were still at least 20 miles from the base of the storm, but we could see the rain free base, which was beginning to widen and showing hints of developing a wall cloud.  So we decided to move in closer so we could be in position for any tornadic activity.  As we were driving toward the base, we learned of a tornado warning being issued for this storm, which seemed to be warranted given the mid-level rotation which we were observing.

By ~6:30-6:45pm, we reached the base (we were now ~5 miles from the storm), just in time to watch the wall cloud really get its act together.  A long inflow tail rapidly developed and was rotating cyclonically around the low-level mesocyclone...this was incredible to watch.  The updraft was also extremely photogenic, and was taking on a classic horse-shoe shape, with a laminar appearance at the base curving back toward the southwest.  During the next 15 minutes the wall cloud continued to develop, and rotation was really tightening up.  We were hoping to see an RFD make an appearance, which would have been a sure sign of imminent tornadogenesis.  Unfortuanetely, just when a tornado appeared to be a sure thing, the storm couldn't maintain its forward flank outflow anymore, and a cool gust front rapidly surged south...oh well.  Regardless of the fact that a tornado wasn't produced, this chase was still an outstanding experience.  The structure this supercell displayed was awe inspiring...definitely one of my top chases.

AUGUST 16: SOUTHEAST SOUTH DAKOTA/NORTHEAST NEBRASKA (Supercells)

Brian Thalken, Jason Ehmke, and I made it up to Mitchell, SD by 4:30pm.  We were anticipating a warm front, which was moving north through Nebraska to make it up into Southeast South Dakota by late afternoon, however, at 5:30pm, we observed several large towers erupt about 50 miles to our south...so it was obvious that we had overshot the warm front just a bit.  We made our way south, and by 6:00-6:30, we positioned ourselves to the northwest of a cell displaying decent updraft rotation, but it was having a hard time maturing.  We followed this cell east a bit, but then decided to give up on it and head further southeast toward Yankton, SD.  As we were heading toward Yankton, a tornado warning was issued for a cell in Knox County, Nebraska (which was moving east/northeast at 25 mph).  We knew we were in a great position to intercept this cell if we punched through the core from the north...we decided to do just that, and experienced the classic progression from heavy rain mixed with small hail, to less rain and larger hail (time was 8pm).  After we exited the FFD rain core, we immediately observed the vault of this supercell towering above us, and we all feared that our windshield was going to be demolished from hail...however, we got lucky and soon left the hail behind us.

What we observed after the hail was a massive, rotating updraft, with a beaver tail streaming into the base.  We drove under the inflow tail and looked off to our west/southwest and observed lots of scud ascending into the base with a hint of rotation.  CINH was pretty high in this region, which probably played a role in preventing a tornado from developing, however, the structure on this supercell was amazing.  The striated updraft towered high above us, with a flanged, hour-glass shape at the base.  10-minutes later (8:20pm), this storm appeared to have spun itself to death, and practically vanished in thin air.  However, there was a second supercell to the northwest of the old one, so we repositioned to the north (8:25pm).  This second cell was rotating just as hard, with a smooth laminar base and a flanged appearance in the mid-levels.  In addition, it also produced a few funnels just after sunset.  All-in-all, today was a great chase...I learned not to give up, even when I'm way out of position.

AUGUST 22: SOUTHEAST NEBRASKA (Supercell)

I had not planned to chase today...but, an isolated thunderstorm developed about 30 miles to my southwest (at ~7:15-7:30pm), but what really sparked my interest in this cell was the fact that it was forming on an outflow boundary (eastern Nebraska had received copious amounts of rain during the previous 3-days).  A quick check of radar revealed a fineline over southern Cass County, NE, and surface-obs showed a thermal gradient present between Omaha and Beatrice, with surface winds out of the northeast on the cool side of the boundary and south winds on the warm side.  I raced southwest toward the cell, and by 8:00-8:15pm I was approaching the base.  A lot of mid-level inflow was present streaming into the updraft, and the anvil looked terrific as it spread out to the northeast above the updraft tower.  About 5-minutes later, I could see the base and a giant wall cloud was present.  After driving south into Otoe County, NE, I finally found a hill and sat and watched as a long tail cloud pointing toward the FFD developed.  I got a few structure shots and then moved further southwest (it looked like it was going to produce a tornado soon).

As I drove closer, the tail cloud grew longer and longer (I estimate it was > 5 miles long).  I parked about 2 miles east of the wall cloud at ~8:30-8:40pm.  The large-scale rotation at the base was quite obvious, but it never could tighten up into a tornado-vortex...however, watching the scud rapidly ascend into the base of the wall cloud was still a fascinating site.  The tail cloud eventually took on a multi-tiered structure, with the top tail cloud (near cloud base) evolving into a long beaver tail.  I gave up on the cell by 9pm (the CG action was too intense).  This cell was eventually given a tornado warning by the Omaha NWS as it moved into Iowa, but it was well past dark at that point.  Very enjoyable chase, good structure, strong rotation, and I didn't have to drive more than 60-miles total.