Tuesday, December 30, 2014

Las Vegas

After experiencing nearly a week of solitude in the desert, I broke the silence on Christmas Eve by spending a day on the strip in Las Vegas.  All of my assumptions about the strip, based mainly on old Hollywood films, were completely unfounded.  Las Vegas has transformed this area into something akin to Disneyland with a twist, the twist being gambling (okay, and strippers).  If one can manage to ignore the street peddlers advertising various forms of adult entertainment (and their peddling is not even that overt, mainly just clicking together baseball-like cards with pictures of naked women on the front), there is really no sign of anything shady or sinister about this 4.2 mile long strip of casinos.  It has become a family friendly mecca of entertainment, dinning, and shopping.

A night stroll through the neon lights is worthy of a visit in its own right.  The strip is alive, vibrant, and full of energy, both literally and metaphorically.  I can’t find any official statistics on the amount of electricity consumed on the strip, but unofficial estimates put Las Vegas as a whole on the order of thousands of MW per day during the summer, with 20% of that being consumed on the strip.  This is opulence on a grand scale, not to mention it is occurring in an extremely arid environment where severe demands on limited water resources are present.  Though Las Vegas and Nevada are making strides toward greater reliance on renewable energy sources and water conservation, the question I kept asking myself was how long can we sustain this desert resort and countless other communities scattered across the drought stricken west, and if we do sustain them, what will be the long term costs?  Is it worth depleting the Colorado River to a trickle?

The fountains of Bellagio.
Planet Hollywood and Paris Las Vegas.
Thousands of tourists pack the sidewalks along Las Vegas Boulevard on any given night.

The Strip viewed from the Paris Las Vegas Eiffel Tower.
Hoover Dam and the Colorado River, sustaining a way of life for much of the desert southwest.

Death Valley

I left rainy southeastern Alaska during the middle of December for the sun soaked Great Basin.  Denise Carl joined me in Vegas via Tacoma, WA, and we headed north across vast desert valleys surrounded by scorched mountain slopes, then made a brief jaunt west from Beatty, NV, up over a mountain pass, and descended into Death Valley.  This valley is a land of big extremes.  The elevation ranges from 282 feet below sea level at Badwater Basin, to 11,043 feet above sea level at the summit of Telescope Peak.  The highest air temperature in the world, 134 F, was recorded on July 10, 1913 at Furnace Creek.  The average annual precipitation ranges from 1-3 inches, with an extremely wet year being 6 inches.  Our trip in December was characterized by temperatures in the 30s and 40s during the morning, and mid 70s during the afternoon in the middle of the valley.  In addition, rain and snow showers occurred as I drove west from Beatty during the night of Christmas Eve.

Mornings and evenings were dedicated to photography…the light was too good to pass up.  During the afternoon, we explored the geologic wonders of the valley.  A full day was dedicated to Sidewinder Canyon, which is embedded in an alluvial fan located ~15 miles south of Badwater Basin.  I forgot the notes I took for this canyon, and we ended up hiking up each individual gully, searching for a popular slot canyon, which we eventually found late in the afternoon.  For what it’s worth, this canyon is located in the far right wash (when viewed from the parking area).  The next day, we drove out to Rhyolite, NV, which is a ghost town located a few miles west of Beatty.  The site is full of crumbling buildings that pay testament to the brief gold rush that occurred in the area during the early 1900s.  We then drove north through Death Valley and explored Uebehebe Crater, which formed as volcanically heated water and gas violently exploded several thousand years ago.  We felt obliged to descend into the 500 foot deep crater, no sweat, but the climb back up was grueling…I can only imagine what it would be like during a hot summer day.

I booked a hotel room at Stovepipe Wells, which is located roughly in the middle of the National Park, very close to the Mesquite Flat Sand Dunes.  The accommodations were simple, but we weren’t looking for luxury, just a base camp to explore the park.  The Stovepipe Wells restaurant provided decent food and friendly service.

Sunset during the descent into Death Valley.
Starry sky above a weathered bush and Mesquite Flat Sand Dunes.
Light painting at Mesquite Flat Sand Dunes.
Mesquite Flat Sand Dunes
Mesquite Flat Sand Dunes
Mesquite Flat Sand Dunes
Mesquite Flat Sand Dunes
Rhyolite, NV, a gold mining ghost town.
Rhyolite, NV.
Uhebebe Crater
Badwater Basin, 282 feet below sea level.
Evening shadows in Death Valley.

Valley of Fire

Valley of Fire State Park is located about an hour north of Las Vegas.  It derives its name from the brilliant red sandstone that prevails throughout the park.  Erosion has carved the sandstone into complex grotesque shapes.  In some ways, these formations are similar to Arches National Park in Utah, though perhaps at a less grand scale.  In addition, there is a formation located near the end of White Domes Road, called the “Fire Wave,” that is very similar to “The Wave” in northern Arizona, though not as colorful, intricate, and expansive as its Arizona counterpart.  I spent two days in the park, but didn’t get a chance to photograph the sandstone landscape during the best light of morning and evening.  Short trails are located throughout the park, the most popular being White Domes, and the Mouse Tank, where hundreds of Anasazi petroglyphs can be viewed.

"Seven Sisters" sandstone formations in Valley of Fire State Park.
The "Seven Sisters"
"Seven Sisters"
"Seven Sisters"
"Seven Sisters"
Sunrise viewed south of Valley of Fire State Park.
Sunrise viewed north of Valley of Fire State Park.
Sunrise landscape north of Valley of Fire State Park.
The "Fire Wave."

Friday, November 21, 2014

Storm Chasing Summaries (2002-2009)

This is an attempt to archive memorable accounts of storm chases I have experienced, starting in 2009, and then going back in time.  Unfortunately, most of the links to pictures are dead.  I will edit these out in time.


While driving west from Haskell, TX, I spotted a large updraft tower erupting to the northwest in Floyd County TX at around 4:30 pm (picture).  I made my way north on highway 70, and reached the updraft base by ~5:30 pm.  It had LP characteristics initially, and was virtually stationary (which may have aided in yielding an LP storm type, due to the stronger storm-relative anvil layer flow).  The storm had visually impressive mid-level rotation (picture), which soon developed at the base as well (picture).  Inflow picked up by 5:40 pm (surface winds estimated at around 30 mph), and a wall cloud developed (picture), followed by a clear slot on the back side of the updraft (picture).  Low-level rotation briefly intensified during this process, but couldn't tighten up into a strong vortex.  

The storm went through multiple RFD cycles/occlusions during the next 30 minutes, but still failed to produce a tornado.  I then had to drop south back toward Matador, TX, and north on TX 94.  While doing this, I spotted another updraft base 20 miles to the west.  A large tube shaped feature was extending down to the ground, and I thought it might be a tornado, but then second-guessed myself and decided it was just scud.  I learned later that it was indeed a tornado which occurred near Cedar Hill, TX (I wish I would have taken a picture of it).  While heading northwest on TX 94 in order to reposition in front of the updraft base, I crossed paths with Rich Thompson and Roger Edwards.  I pulled over and watched the striated storm (picture) with them (David Hoadley pulled up a few minutes later)...with a few scudy fingers extending toward the ground.  The storm quickly morphed into an outflow dominant HP supercell during the next 30 minutes, and I decided to call it a day.


After driving all night, I reached Sterling, CO by noon.  I ate lunch in Sterling, met up with Brian Thalken, and then drove west and then north toward Kimball, NEB (where I saw VORTEX-2 waiting for storm development: picture, picture, picture), and then further north to Harrisburg, NEB.  After turning west on a paved county road, I passed the VORTEX-2 armada near the WY/NEB state line, and drove further west past La Grange, WY where I positioned just east of a developing supercell (picture, picture).  I had an excellent view of the storm, watching it develop classic updraft structure, reorganize its wall cloud, and then develop intense low-level rotation.  A long inflow band developed along the storms northeast flank (picture, picture), with a translucent precipitation core to its north (surely filled with giant hailstones, as I would soon find out).  

As the storm slowly drifted east-southeast, a new wall cloud organized, with broad cloud base rotation intensifying (picture, picture).  Then, a small precipitation core developed on the south side (I believe) of the wall cloud...rotating around to the north side, and rotation became more focused (picture, picture).  A thin needle tornado developed after several minutes...then a translucent tube, and then finally a large solid cone shaped cylinder (picture).  I unfortunately decided to take a north road toward the growing tornado, and got caught between the hail core and the tornado.  Hail up to at least baseball size started pounding my car, producing some decent size dents as well as a cracked wind shield.  I also ended up sliding off the edge of a muddy road and became high centered, but luckily was able to work my way out of that situation without having to be towed.  The sad thing is that I didn't even get decent photography of the tornado, but probably could have if I drove east away from the storm...so experiencing the hail and tornado up close doesn't appear to be worth it.


Brian Thalken and myself observed a long-lived supercell in northwest Kansas.  After finishing supper in Arapahoe, NE, we saw on radar several cells showing signs of intensifying within a region of steep low-level lapse rates south and north of Goodland, KS.  One of these storms quickly displayed supercellular characteristics east of Goodland, which we quickly decided to target.  After maneuvering through a series of farm roads, we eventually reached highway 36 east of Oberlin, KS.  We then gained a position between Oberlin and Selden on highway 83 (time was ~7:30 pm CDT), and parked directly east of the approaching supercell (this was our initial view of the storm).  

The storm was developing mid-level inflow bands, but was also high based due to the rather limited low-level moisture and steep low-level lapse rate environment.  We hoped that as it moved east into deeper moisture, the storm would further intensify...we also knew that low-level shear/hodograph curvature was forecast to increase substantially by sunset...so we remained patient.  By 7:50-8:00 pm, a second storm approached and merged with the storm that we were observing.  It was after this merger took place that things really got interesting.  Surface inflow steadily increased as we moved south down to Selden, KS (estimated to be around 40-50 mph), and mid-level rotation became much more apparent (inflow band picture #1, inflow band picture #2).  The storm started taking a hard right turn, and by 8:30 pm, a large wall cloud  began to develope (see picture here) as rain cooled air was pulled into the updraft base from the forward flank downdraft positioned to the north.  

We both believed (as I'm sure everyone else did as well) that the storm was getting very close to producing a tornado.  However, a cold surge of outflow rapidly undercut the updraft base, causing the wall cloud to dissipate and the storm to accelerate further to the south and east.  Interesting mid-level inflow features were still present (such as the one here) though, and new wall clouds formed every 10-20 minutes.  We then made our way to highway 24 east of Hoxie, KS.  A new mesocyclone developed east of the old one as we went south, with updraft rotation further intensifying and taking on a horseshoe shape.  Darkness began to set in as we approached Hill City, KS...with photography becoming more challenging.  Plus, I had to work at 8:00 am the next day...so we gave up on this storm just before it moved through the Hill City area (~9:30 pm).  The storm continued to move east across northern KS through the night, and produced a 1/2 mile wide EF2 tornado near Beloit, KS at around midnight.  Regardless, Brian and I were happy with what we saw...it was a great way to start off the 2008 season.


Brian Thalken and myself decided to target the I-70 corridor just south of Hoxie, KS.  Our plan was to pick up new cells moving north toward that location, follow them to the north side of a warm front aligned east-to-west (where low-level mesocyclogenesis would take place), and then leave the cell as it moved north into colder air and catch a new cell as it moved north toward the same location.  This strategy yielded five tornadoes, produced by 3 different supercells.  The first supercell we observed (here) was located 10 miles southeast of Grinelle, KS.  It had some interesting scud-like fingers (here) dangling from the base which eventually consolidated into a big wall cloud (here, and here).  However, visibility was poor beneath the updraft base, and we quickly left this storm after it crossed I-70.  We then repositioned south of Grainfield, KS (time was ~5:10 pm CDT) and picked up a new supercell about 10 miles south of the interstate.  

This storm rapidly developed a classic wall cloud, followed by a strong occlusion that led to a divided mesocyclone.  The clear slot continued to eat away at the base of the updraft, which eventually focused a new area of cloud base rotation on the northeast side of the base (here).  A horizontal funnel soon developed at the updraft/downdraft interface, and the RFD then appeared to re-orientate it into a vertical position, producing a funnel that occasionally produced dust whirls at the surface ("touchdown" was at around 5:25 pm).  The developing tornado (and here) continued to move north toward Grainfield, then crossed I-70 (~1 mile west of Grainfield) at which point it developed into a slinder elephant trunk tornado (here, here, here, and here) that was in contact with the ground until it roped out (~5:48 pm).  

Believing that the tornado threat was over with this supercell (we were wrong, it went on to produce several large tornadoes), we headed back south to intercept the next supercell.  By 6:11 pm, we were approaching a very large rain free base with a massive clear slot/RFD and large wall cloud about 10-20 miles south of Collyer, KS.  The wall cloud was displaying strong rotation, which soon extended to the surface and filled up with dust and rain (picture here shows the large clear slot, RFD winds kicking up dust, and tornado filled with dust and rain on the right side of the image...time is ~6:20 pm).  The tornado and RFD appeared to be moving toward our location, so we repositioned east on a county road.  We then noticed a new tornado forming beneath the east side of the RFB (~1 mile to our south).  It was weak, and appeared to dissipate...however, as we attempted to get east out of its way, I began to notice my ears popping and an increase in wind gusts.  Apparently this weak circulation passed right over us, because in a matter of 1 or 2 minutes, we looked northwest across a field and saw a debris cloud with a funnel dangling beneath the updraft base (here).  Its possible that this was an anticyclonic tornado due to its location with respect to the cyclonically rotating low-level mesocyclone.  We then followed this supercell slightly behind and to the east of what was now very intense low-level rotation.  We were anticipating the development of a wedge on the magnitude of Hallam or Greensburg (based on the width and intensity of the rotating wall cloud).  While driving north, we observed another tornado embedded back within the clear slot (~5-10 miles to our west).  As the storm crossed I-70, its RFD quickly filled with precip (here), and therefore we quickly gave up the pursuit.  We then headed south to I-70 once again, monitoring weak-looking storm activity to our west. 

We began to get the impression (or at least I did) that the chase was coming to an end.  However, there was one more cell way down to the south that we wanted to let intensify and move north, hoping that we would get one more tornado before sunset.  We drove east to Wakeeney, got gas and food, and then reassessed the environment that this southern storm had to work with.  Ingredients still looked good for tornadoes, which seemed to be confirmed by a tornado warning the second we got on highway 283 to drive south toward the storm.  As we approached the updraft base, we soon spotted another fairly classic looking wall cloud, with a long tail-cloud streaming in from the north (here).  Lightning was occurring in close proximity in every direction, and the sun was setting, so that wall cloud picture was the last photo-op of the day (but video was still good...time was ~8:26 pm).  The wall cloud was soon infiltrated by RFD winds from its back side, and this set in motion a processes of vortex intensification as the RFD contracted around the broadly rotating low-level meso.  As we were repositioning toward the northeast, a large cone shaped funnel extended toward the ground.  It was quite a site to have this developing tornado fill my rearview mirror as I was quickly moving east away from the location.  Just after the cone shaped condensation funnel made contact with the ground, rain curtains rapidly wrapped around the tornado, and our view was blocked.  

More excitement was on the way though!  The storm was turning sharply right (possibly due to a change in upper-level flow during the evening), which seemed to favor a quick transition to an HP supercell.  For those of you who chased near Concordia, KS on May 29, 2004 and were caught by that land-hurricane of an HP supercell...this was a repeat of that experience.  As we reached the intersection of I-70 and highway 283, we were quickly engulfed by near-hurricane force winds with quarter size or larger chunks of hail.  What was worse is the fact that we knew there was probably a rain-wrapped tornado moving northeast toward our location.  So I decided to jump on I-70 and drive through the landcane away from the most likely path of the rain-wrapped tornadic circulation.  It was a huge relief to eventually see the outer edge of the rain-filled RFD...and our day was done.


I intercepted a developing supercell (initial view) 20 miles southeast of Bridgeport, NE at around 5:40 pm (CDT).  This storm had a large rain free base (here), which was beginning to produce an agitated region of ingested scud by 5:50pm (here).  As the storm continued to intensify and develop stronger mid-level rotation, it began to turn more sharply to the right.  So I began to move back to the south on highway 385.  A ragged wall cloud began to develop (6:40 pm) as I did so (here), and began to grow in size during the next several minutes (here), though rotation was still fairly broad.  

A tornado warning was now in effect for this storm, and the wall cloud became more impressive (here, here, and here).  Interestingly, scud was being sucked off of the ground immediately to my southwest (here), which was fascinating and a bit intimidating (given this area was closing in on my position quickly).  In order to stay close to the updraft base, I decided to go east on a county road near Dalton, NE (luckily I didn't get lost), and occasionally observed gustnadoes forming along the flanking line of the supercell (which apparently led to a bad tornado report later in the day at sunset).  While driving through the backroads of the NEB panhandle, I was able to capture a few scenic pictures of the countryside with the storm in the background, such as this one.  

I eventually reached Lodgepole along highway 30 by 8:06pm, and had a nice view of the storm while moving east (here).  Six minutes later while moving through Chappell, NE, broad cloud base rotation increased again, with a beavers tail noted off to the northeast and a hail-filled precip core off to the north (see picture here).  While driving south through Julesburg, CO, I finally gained a better position to take in the full structure of this supercell (here).  I continued moving south of Julesburg by a few miles, and was able to observe some incredible storm structure at sunset--complete with a newly formed wall cloud at the base and a laminar inflow tail streaming into the storm from the east (here, here, here, here, and here).


I started the day off in far western Oklahoma, and after a forecast update from Brian Thalken and Ryan Presley, decided that the northeast corner of the TX panhandle looked like a good place to hang out.  I arrived in Perryton, TX by 3pm, and watched an agitated Cu field evolve off to my west.  By 4pm, I decided that southwestern KS might have a better shot at significant severe weather due to stronger backing of the surface winds, so I headed north on highway 83, and reached Liberal, KS by ~5:30pm.  Weak updrafts were developing, and struggling to mature at this point.  I decided to follow a mushy looking cell northeast, but it was not showing signs of intensifying, so I then decided to race east toward Dodge City, KS and then head south on highway 283 in order to intercept a storm that was producing quarter size hail.  I punched through this cell at ~7pm, but the south side of the storm was also mushy, and seemed to be associated with a strong area of warm air advection/isentropic lift.  Things were getting a bit depressing for awhile, but I soon learned of a tornado warned cell moving northeast through Harper County Oklahoma, and I realized that I could intercept it as it crossed the KS/OK border.  So I moved south toward Sitka, KS (Clark County KS), sat in the storms rain core for 10 minutes, then decided to head further south through the core, sat south of Sitka for 5 minutes, then decided to turn around and move east along highway 160 toward Protection, KS (Comanche County KS).

As I drove east toward Protection, KS, I had to punch through the region of the storm with the most intense rainfall and hail.  Hail stones were easily 2 inches in diameter--any larger and I probably would have lost my windshield.  After 5 minutes of core punching, I emerged from the heavy rain, with only sporadic large hail stones falling.  I was directly to the north of the storms low-level mesocyclone.  I could see a long rain free base (RFB) to my south, with two bowl shaped lowerings, and a massive "vaulted" appearance to the updraft towering above the RFB.  A tornado quickly developed out of the eastern meso--it was a thin rope like tornado that was slowly being absorbed by a stronger meso ~2 miles to its west.  I moved about a mile east in order to let the western circulation cross the highway.  This circulation quickly contracted into a small barrel shaped tornado as it moved over hwy 160--there was strong cascading motion on its eastern side which seemed to bring the circulation and condensation funnel down to the ground.  A tornado shaped like an elephant trunk then formed about 4 miles west of the second tornado, and lasted for about 10 minutes.  A fourth tornado then formed 2 miles east of the 3rd tornado, and became wrapped in a thin veil of rain--this tornado was also shaped like a small thin cone.  A fifth slinder tornado then formed several miles east of tornado number 4, but only lasted about a minute.  

The base of the storm continued to rotate as it slowly moved northeast of my location (and just northwest of the town of Protection, KS)...the storm almost produced a 6th cone-shaped tornado, but condensation never developed at the surface, and I could never verify debris or dust being kicked up (so I won't count that one, although it was 1/2 way to the ground).  The 'tornado window' lasted about an hour, and then rotation at the base of the storm steadily weakened.  Due to poor lighting and a rapidly evolving situation, I was only able to shoot video.  I let the storm go as it moved north of Protection, KS, and repositioned back toward Wichita, KS for the next days action.


I got lucky again west and north of Hutchinson, KS today.  A storm went crazy during the late afternoon--I nearly passed it up in order to make the long drive back to Paducah, KY, but gave it one last chance (I was well rewarded for my patience!).  I started the day off in Wichita, KS, gathering data in my hotel room.  Deep shear vectors were pretty much parallel to the dryline from TX north into KS, which seemed to hint at an early transition to a linear mode of convection.  The dryline seemed like it might arc back to the northwest over KS (which could increase the crossing angle between the line of forcing and shear vectors, favoring a more discrete mode of convection), and a surface low was forecast to deepen in southwest KS resulting in stronger backing of the low-level flow--so I decided to stick around southcentral KS, and drove west to the intersection of highway 54 and K14 (just west of Kingman, KS; ~2:45pm).  Skies rapidly cleared over this location, and the Cu field along the dryline began to perk up in response to the insolation.  Solid looking towering cumulus would occasionally develop, but then die off--this process continued through 5pm.  Once again, I was getting nervous that the day would be a bust, and considered taking off for home.  By 5:15 pm, I had repositioned to the intersection of highway 50 and K14.  

A newly developed storm intensified and was producing an anvil.  Several other cells were forming to its south/southwest, so I raced west on hwy 50 toward the base of these storms.  A broken line of storms developed by 5:30pm, and by 6pm, a storm developed a strong inflow band feeding into its base.  This cell was moving north into the precip core of a storm downstream, and it soon weakened.  I let this storm go and went back south, eventually passing through the forward flank precip core of an LP'ish looking storm.  Once I reached highway 50, I decided to head east away from the updraft, contemplating leaving all of this 'weak' convection behind.  For some reason, I decided to pull off the highway 2 miles east of the storm in order to take some structure shots (see here, and here).

At around 6:45pm, this storm started to develop a small clear slot at the rear of its updraft.  The clear slot continued to notch around the updraft (here) as rotation intensified (here).  At ~7pm, a small funnel developed at the base of the rotating updraft (here), and started 'reaching' down toward the surface (here).  I heard reports over the radio that dust whirls were observed at the surface, but the funnel soon dissipated, although the broad scale rotation at the base of the storm was still strong.  The low-level mesocyclone reorganized during the next few minutes (here), and another weak funnel developed (here).  Rotation grew stronger, and dust was again observed at the surface (here and here).  The condensation funnel evolved into a cone shape (my favorite shots here and here), and the dust whirls tightened up into an intense vortex at the ground (although only briefly--dust whirls start to dissipate here).  

The storms low-level mesocyclone started to occlude by 7:40pm (here), and rotation at the base of the storm weakened quite a bit (although a brief vortex reformed along the intersection of the rear-flank gust front and main updraft base).  I then raced off to the east in order to take a few more shots of the updraft structure (here and here).  There were at least 100 or so cars scattered across the county, and everyone was repositioning toward the northeast--it was obvious that the storm was considerably weakened and probably no longer a tornado threat, so I decided that I had my fill of chasing for the day, and took off in the other direction toward Hutchinson.  It is worth noting that thunderstorms north of the eventual tornadic cell put down quite a bit of rain--the southern cell then intensified and moved across this swath of precipitation.  The rainfall may have laid down a low-level thermal boundary, aiding in tornadogenesis as the southern cell moved north across the area--just something to point out.


Brian Thalken, Jeremy Wesley, Ryan Presley, and myself left Hastings, NE during the late morning, targeting an area northeast of Dodge City, KS.  We arrived in Kinsley, KS at around 3pm, and began the long wait for convective initiation.  We were sitting on the nose of an axis of steep low-level lapse rates, with a very unstable atmosphere in place coupled with strong vertical wind shear.  The atmosphere was primed for intense deep moist convection-the only caveat was a layer of warm air at around 700 mb.  Cooler mid-level temperatures were indicated by the RUC over far southwestern KS, and would reach our area by evening.  A Cu field was present east and north of Kinsley, which made us re-think our outlook on where convective initiation might take place.  We repositioned northeast toward Great Bend, KS, and at 6pm, decided that initiation was most likely to our north.  At 6:30pm, a large towering Cu erupted over Smith County, KS-so we raced toward it on hwy 281.  As we entered Osborne County, KS, a large back sheared anvil became apparent with a trailing flanking line feeding the main updraft tower (here and here).  

We finally gained a position east of the updraft base in Smith County at the intersection of hwy 9 and 281 (time was ~8pm).  Updraft rotation was quite obvious, with a large bowl shaped rain free base and a long beavers tail feeding into the northern portion of the updraft (here, here, here, and here).  Low-level rotation quickly strengthened, which must have induced a downward directed vertical pressure gradient force, because the updraft quickly occluded, leading to a divided mesocyclone-like structure.  The storm was moving through a thin veil of broken stratus, which likely indicated the presence of significant convective inhibition-this seemed to be a negative factor toward the development of a tornado.  We then drove north through the storms hail core as the rotating updraft approached, and ended the chase east of Smith Center, KS with a vivid lightning display to our north.

Meanwhile, everyone is aware of what transpired back to the south.  We were too far out of position to retreat back to the south and intercept the massive supercell that initiated fairly close to where we had initially targeted.  It is obvious now that the approaching mid/upper level speed max from the southwest rapidly backed the low-level flow, bringing the high theta-e airmass westward...once it hit the axis of nearly dry-adiabatic low-level lapse rates, violent convective initiation occurred--the rare combination of very large CAPE and strong deep and low-level wind shear resulted in the violent tornadic supercell.  I hope for a speedy recovery for the people of Greensburg and the surrounding region.


Ryan Presley and myself spent the night in Concordia, KS-we woke up to a high risk over most of the high plains of Nebraska and Kansas.  After a data check, we decided on a target around the Jetmore/Ness City, KS area.  We reached the city of Hays, KS at around 1pm, and then went south on hwy 183--passing by marginally interesting convection every 30-minutes or so (here).  All of the updrafts we observed to this point would briefly intensify before turning to mush, which was likely a function of early convective initiation and a veil of cirrus that stretched east as far as the eye could see.  At 2:45pm, we encountered a storm that displayed significant bowing (here), but it did not appear to hold much tornadic potential.  So we continued south to hwy 50, and began heading east.  

This chase appeared to be heading downhill in a hurry, and a long drive back to Kentucky still loomed large in the back of my mind.  At 4pm, radio reports noted a strong storm developing over Kiowa County, KS (which was to our south)--at 4:30pm we approached Stafford, KS, and observed the large storm to our south, which had a nice updraft tower with a massive anvil spreading out to its north and east (here and here).  We quickly decided to take a county road south toward the base of this storm, and within 10 minutes we could observed the rain free base, and a cone shaped funnel extending about half-way to the ground.  We pulled up next to the base, and observed scud rapidly ascending into the RFB (here).  We moved east and north several miles, and low-level rotation quickly strengthened, with a violently rotating wall cloud (here, here, here, here, and here) occasionally producing vigorously rotating vortices at the surface (~5:18pm).  We then re-entered the town of Stafford, and moved north and east one mile.  The storm produced an amazing rotating wall cloud over Stafford at ~5:31pm (here and here).  We then had to move through a maze of different roads in order to keep up with the storm, and ended up near the town of Lyons, KS.  The storm apparently produced another tornado while we were driving through an area of trees, but it had generally weakened as we reached hwy 56 (~6:40pm).  

Another tornadic storm was approaching Great Bend, KS (~6:43pm), so we repositioned back towards the west, and intercepted this storm as it moved along hwy 156 (~7:12pm).  Rotation was quite obvious within a rain-wrapped wall cloud, with thin rain curtains dancing around the base of the storm.  We then let this storm go, and approached another tornado warned storm near Seward, KS at around 8:40pm.  It was very dark at this point, but we could observe a lightning-lit lowering--we couldn't make out any rotation, and decided to end the chase shortly after that point.


Everything looked absolutely perfect for a widespread tornado outbreak today, and my sister and I quickly made our way down to St. Joseph, MO by noon in order to get a data update.  Thunderstorms had rapidly developed in eastern Kansas, with the northern most cell developing near Kansas City.  We decided to move further east toward the town of Cameron, MO so that we would be in better position for intercepting the storms to our southwest (which were rapidly moving east/northeast at 50 mph).  After a radar update from Brian Thalken (who did a great job nowcasting), we decided to let the storm over Kansas City move up to us.  This cell had a tornado warning, and we were directly in its path.  Unfortunately, the warm front had not yet lifted north to our location, and this storm moved into a cooler, more stable airmass, which prevented it from producing a tornado.  After we realized that it was moving through a bad surface airmass, we were faced with the challenge of having to race south and east in order to catch up with strong tornadic supercells that were moving east along I-70.  We believed we had a chance to catch the southern most cell, and eventually reached I-70, at which point we were about 20 miles west of the storm.  This cell had the most massive back sheared anvil I have ever seen...and we had little doubt that it was probably producing a tornado.  We finally reached the rear flank of this storm at ~5:10 pm as we were entering Columbia, MO.  The storm had a very large clear slot wrapping cyclonically into the updraft.  Unfortunately, rain was cascading around the back side of the updraft as well, which prevented us from observing the tornadic region of the updraft base.  We still decided to continue east, but by this time it was getting dark and we knew that a long drive home was still waiting for us.  So, we let the storm go at around 6 pm.

As we approached Boonville, MO (~7-8 pm), we suddenly ran into a massive traffic-jam on the westbound lane of I-70.  To make matters worse, not one, but two tornadic supercells were moving east-northeast toward our location.  Luckily we had a cell phone connection and were able to constantly receive radar updates from Brian.  We got off of I-70 near Lamine, MO, and eventually decided to move south so that we would be out of the path of an approaching tornado (radio reports described it as a large tornado, about 20 miles to our southwest).  After driving south of Pilot Grove, MO we found a hill which provided a great view to the west, and we witnessed a massive, beautifully sculpted mesocyclone move past us to the north (Brian described it as having a picture-perfect hook echo on radar).  In addition, present underneath the updraft was a large wall cloud with a long inflow tail that swirled into the lowering.  We never could see a tornado within this wall cloud though, as precipitation began to fill in around the region of strong low-level rotation.  Regardless, being in position to watch this lightning-lit supercell at night partially made up for the frustration we experienced earlier in the day.  In hindsight, it would have been wise of us to target central Missouri where the moist, unstable warm sector was large instead of targeting the first storm near the warm front...another lesson learned!


I got off of work at 3:15 today, and raced down I-29 to St. Joe.  Surface winds at this location had veered to the southwest, and I heard reports of a tornado warned storm 30-40 miles to my east, so I decided quickly that this was the storm I needed to intercept.  At 6:30, I approached Chillicothe, right on the heels of a tornado to my east.  The back side of the updraft was the most helical thing I have ever seen.  I soon observed several different debris paths as I moved east through the town, with a grain bin in the middle of the road, a semi flipped over, minor damage to houses, and trees in the middle of the road.  After I passed through Chillicothe, I spotted a hybrid cylinder/cone tornado about 5 miles due east at ~6:45, which was barely visible in normal lighting, but was spectacular when back-lit by lightning.  This tornado dissipated soon after I spotted it, and I raced east in order to get ahead of the base of the updraft.

Soon after I got out in front of the storm, inflow winds rapidly increased...I would estimate between 30-50 mph.  The storm was really beginning to rotate hard at this time as well.  A distinct area of low-level rotation became visible off to my northwest, and I decided to pull over at a truck wash and let the storm approach me.  Violent rotation could now be observed, and a large tornado became faintly visible underneath the dark base at around 7:35 (location was near Brookfield on highway 36).  After 5-10 minutes of video, I then raced east again.  The structure this storm was displaying was amazing.  The updraft was a huge cylinder, wrapping around toward the north-northwest.  I used a wide angle lens to capture this, and have been very impressed with the results.  I continued to follow the storm east on 36 all the way to Monroe City, MO.  The storm put on a great lightning display, with bolts dancing around and lighting up the huge mesocyclone as night-time set in.


My sister Melissa and myself reached the Concordia, KS area by 2:50 and waited for initiation, which didn't take too long.  At 3:15, towers began to erupt to our west, and by 4:15, we were approaching a developing supercell southwest of Concordia.  As we approached the RFB on highway 24, we immediately spotted a slinder, needle thin tornado at 4:38 near Asherville, KS.  It dissipated 20 seconds later, but then redeveloped after a minute or so.  Then, the RFB went through a period of reorganization during the next hour.  Inflow from the east picked up to 40 mph during this time, and at 5:50, a new wall cloud developed to our northwest.  We rapidly repositioned, heading north towards Jamestown, KS.  At 5:54, an elongated cone tornado developed on the south side of the wall cloud, but dissipated about a minute or so later.  However, the rotation within the wall cloud was becoming violent, and it was obvious that a large tornado was about to form any minute.  

We went north several more miles, and then parked just as the debris cloud developed underneath the wall cloud.  This debris cloud rapidly filled with dirt, and then expanded rapidly to about a mile in diameter.  Rain was also being pulled around the circulation, but was thin enough so that we could still see the tornado for about five minutes.  Then, rain completely wrapped around, and our viewing position was no longer favorable.  During this time, an anticyclonic tornado developed five miles to our west.  We drove north a bit to find a road option around the big tornado, but did not succeed, so we went back south, and then observed the anticyclonic tornado lofting a lot of debris, including pieces of man-made structures high into the air.  We decided to park, and got about 20 seconds of video (I was able to look almost straight up at the tornado at this time).  We then headed a bit further south, just in case the tornado overtook us, and then headed back north towards Jamestown.

At Jamestown, we spotted another very thin tornado west of town which was producing a vigorous debris cloud at the ground.  We decided to let this tornado go so that we could catch back up to the storm.  By 6:50, we passed through Concordia and then raced north on highway 81.  The edge of the supercell was just north of us, so we went east on highway 148, and managed to get about five miles east of the meso, which had evolved into a classic wedding cake by this time (at times, a stack of plates was present from the base all the way up to the anvil).  During the next 30 minutes or so, the supercell displayed strong rotation at the base, with cone shaped lowerings approaching the ground.  However, we could never confirm whether anything touched down during this time because it was too dark underneath, and rain wrapping was becoming a serious problem (the storm had quickly evolved into an HP monster).  At 8:07, we parked near Narka, KS and continued to observe very strong inflow and rotation.  

My logistical senses went down the drain during this time because I was so focused on spotting a tornado back near the rain core, that I forgot to keep track of an escape route.  So...to make a long story short, the rain wrapped meso overtook us, with violent rain bands surrounding us (I was sure I felt the car being lifted off the ground several times) and golf ball size hail pounding my car.  I wasn't worried about dents, but I didn't want the windshield to be destroyed.  Luckily, we survived this ordeal (with just minor hail dents on the hood and top), and hopefully, I have learned from that mistake.


Brian Thalken and myself left Omaha at about 5pm today (somewhat of a late start).  A thunderstorm had rapidly developed in southeastern Nebraska before we left, and was moving east into southwest Iowa, where a very unstable and highly sheared environment existed.  I was aware that the storm had gone through a split right before we left, and we encountered the northern split as we went south on I-29.  After entering the northern split, we exited off of the interstate and headed east.  As we got gas in Sidney, IA (~5:45pm), the Omaha NWS issued a tornado warning for the southern split.  We were "embedded" within the right-turners forward flank precip core.  During the next 30-minutes, we drove east down highway 2 battling the heavy rain, then went south toward the town of Coin, IA.  Just before reaching Coin, we exited the precip core and a massive mesocyclone towered above us.  The storm was highly sculpted and rotating hard.  We headed a mile or so west of Coin in order to observe the base...a strongly rotating wall cloud was present with an impressive clear slot wrapping toward it.  

We were soon forced to go east in order to stay ahead of the low-level mesocyclone.  As we approached College Springs, IA, the low-level rotation began to intensify even more, taking on a skewed horseshoe shape with an area of agitated cloud tags in the middle.  We soon found a place to park as the mesocyclone slowly moved east.  Soon, a long condensation tube reached for the ground (~6:35-6:45), followed by a 5-10 minute period of suction vortices dancing around an invisible origin.  An incredible weird twist of fate had suddenly developed.  Brians sister and brother-in-law's house was right in the path of this multiple vortex tornado.  Luckily, the tornado missed their house by a few hundred yards, but unfortunately, their neighbors house was hit.  We could easily see trees and debris getting sucked into the tornadoes inflow as it passed by their house.  After the mesocyclone passed by and slowly dissipated, we let the storm move on to the east and went back to check on Brians family.  Everyone was ok...what an intense chase!

MAY 8, 2003; NORTHEAST KANSAS (Tornado)

Jim Kaiser, Brian Thalken, and myself made it to our target of Randolph, KS by early afternoon.  Shortly thereafter, a severe storm with a tornado warning was moving through the Concordia, KS area to our west, so we decided to intercept this cell.  At 4pm, we were in great position to view the base, however, we went north on a mud-road, and Brians truck got stuck...luckily, for some miraculous reason, we got out of the mud (it took 30 minutes to travel down 1.5 miles of this road).  By this time, the tornado warned storm had moved off to the northeast (into a fog bank), therefore we decided to reposition ourselves back toward the east.  At 5:45pm, we entered Manhattan, KS as another tornado warned cell was moving east through the area.  We had no choice but to follow this cell from behind on I-70 (the FFD, which was likely putting down large hail, was directly ahead of us).  A violent wet microburst caught up with us as we were following the cell, so we had to pull off of the interstate (driving was impossible!).  

After the downburst passed, we continued east on I-70, and eventually entered Shawnee County Kansas.  A tornado warning was again issued for our cell, and we could view the rain free base from the interstate (no rotation observed).  After we went through Topeka, KS, we let our cell move away toward the northeast, and decided to target another cell south of us, which was moving northeast through Osage County (producing multiple tornadoes).  We quickly made our way to Lawrence, KS and decided to travel south down Iowa Street were we could then reach the rain free base.  As we approached 27th and Iowa Streets, a tornado rapidly developed about a mile or so to our west/southwest, moving over the southwestern portions of Lawrence.  This tornado formed at the edge of the parent updraft, where the clear slot could be observed cutting into the base...it briefly took on a cone shape (we observed it for several minutes, then the parent storm just vanished into thin air).  The city of Lawrence was pretty lucky, if the storm hadn't have dissipated so quickly, then the tornado would have moved through a densely populated region.


Steve Peterson and myself had a great (albeit long) chase today.  We targeted the Chillicothe, MO region, however, we continued to make our way further east into Missouri in order to better assess developing convection around us and to our west.  At 4pm, we decided to intercept a cell in Carroll County, which was soon given a radar-indicated tornado warning.  We missed a north road which would have put us right in front of the base, so we had to make up ground behind the cell...it had a large rain free base and a disorganized wall cloud.  By 5:15pm, we were heading back east on highway 36, and were now ~20 miles behind the storm, but managed to catch up, and at 5:40pm, we entered Shelby County, with the cell a few miles to our north (it had a large rain free base and possible clear slot).  There was another cell to our south in Randolph County which also had a radar-indicated tornado warning...it was beginning to dump precip into our cell, so we blew-off the northern cell, and dropped a bit south of Hunnewell, MO to get in front of the base of the southern cell.  

This supercell soon developed a weak tail cloud extending east from a small wall cloud...it also appeared to be outflow dominant (it turned out that this was the RFD).  We let the cell pass over us (with marble size hail falling), and then got back onto highway 36...as we moved east, we spotted rain curtains beginning to circulate around what was now an obvious low-level mesocyclone.  We followed the mesocyclone closely from behind, and at Monroe City, MO, the circulation tightened up and a tornado formed at 6:30pm (we observed debris in the air in Monroe City).  The tornado passed over highway 36, and then began to veer east, moving parallel to the highway.  We blasted east, and then stopped along the side of the highway, where the tornado rapidly intensified (awesome experience being only 1/4th of a mile from the vortex).  This tornado went from a needle, to a cone, then a cylinder, and finally a skinny carrot-shape as it dissipated.  At one point during its life span, scud near the surface was sucked in from behind the tornado, and wrapped around the vortex.  This tornado dissipated near the town of Hannibal, MO at 6:55pm (it was on the ground for 25 minutes, and tracked ~15 miles, +/- 2 miles).

After this tornado dissipated, Steve and I then tracked the supercell into Illinois.  We went north on I-172, and then went east from exit 2.  By 7:08pm, the low-level mesocyclone came back into view...it had a HUGE clear slot which towered high above the updraft base (it looked similar to the May 3, 1999 Oklahoma City tornadic supercell).  As we approached the town of Adams, IL, the circulation at the base of the storm tightened up again, and a tornado redeveloped at 7:28pm (~4 miles east of Adams, IL).  We then made our way north and east (road network was not the best).  The tornado began as a small cone, occasionally displaying a multi-vortex structure...after 10-minutes, it grew into a GIGANTIC cylinder (we were never closer than 5 miles from this tornado, but I would estimate it was easily 1/4th of a mile wide at the base...probably wider).  Interestingly, the low-level mesocyclone dwarfed the gigantic tornado below it, which shows just how strong this supercell likely was.  

As we entered Kellerville, IL at 7:40pm, the tornado was now a full blown wedge, ravaging the country-side (we observed damage to several old houses as well as downed power lines when we crossed its damage path).  Our road network continued to prove difficult, and we lost our visual contact with this tornado at around 7:55pm...but we didn't give up the chase as we eventually reached highway 24, which went northeast toward Rushville, IL.  By 8:10-8:15pm, we once again spotted the tornado (which was still a wedge)...and by 8:30, we were just north of Rushville and observed the tornado becoming rain-wrapped (and most-likely finally dissipating).  Based on its visual appearance, this tornado would have inflicted heavy damage to any town it would have encountered, but thank-goodness this didn't happen...it had a continuous ground track of ~40-45 miles (lasting from 7:28pm to 8:30pm).  What a great experience to get a chance to observe this tornado for so long...it was my first wedge!...congrats to Mike Hollingshead for his catch today as well.

JUNE 9, 2003: NORTHCENTRAL NEBRASKA (3 Tornadoes/Supercell)

Brian Thalken, Mandy Aronson, and myself left Lincoln at 12:40pm today, with a target around Bassett, NE.  After passing through Burwell, we observed towers developing to our west and northwest...we checked radar/satellite/surface data, and saw that a cell was beginning to develop in Keya Paha County Nebraska...so we ignored the towers to our west and continued north to Bassett.  The cell to our north rapidly developed into a classic supercell (both visually and on radar) as we approached it from the south.  At 5:05pm, we drove a few miles east/northeast of Bassett in order to get a better viewing angle of the base and updraft (a large, circular anvil was present above the cylindrical updraft tower).  The rain-free base continued to widen, and took on a circular, bowl shaped appearance at 5:40pm.  Then, weak rotation was observed at the base, with a clear slot starting to "cut" into the updraft...a rotating column/tube of dust was observed under the rotating base at 6:01pm.  We decided to drive further northeast in order to keep up with the base of the storm, observing several more weak tornadoes during this time.  By 6:40pm, a new, more well-defined wall cloud developed, and we approached it from the west.  The circulation was very strong within this wall cloud, and appeared to be tightening up into a tornado, but it couldn't manage to produce (we were about 1/4th mile west of this wall cloud...would have been great video if it produced a tornado).

At 7pm, we repositioned back to the southeast, and then headed east on highway 20.  As we approached Stuart, NE, a new area of rotation under the base of the supercell developed, and soon led to a large funnel at 7:03pm.  We headed north through Stuart toward the low-level mesocyclone, and at 7:06pm, the funnel became more vertical and reached the ground.  The tornado widened a bit into an "elephant trunk"...it took on a ghostly-white color and we could observe the entire parent updraft column above the tornado...very photogenic.  This tornado moved east a mile or two, and then dissipated at 7:15pm.  We then made our way toward Atkinson, NE...during this time, the supercell developed another low-level mesocyclone...we went east through Atkinson at 7:30pm, and again approached the new wall cloud from the west.  

The rear-flank downdraft was extremely strong, and we could observe violent rotation at the base of the storm 1-2 miles immediately east of our location...another tornado had formed, sucking up huge amounts of dust in front of us.  We kept moving east behind the tornado, and the RFD continued to strengthen, with gustnadoes forming from time to time...eventually, we couldn't go any further east because the RFD winds began to knock trees down into the road.  From here, we made our way east toward O'Neill, NE, traveling next to the clear-slot the whole time.  Scud bombs erupted several times under the flanking line, with shear funnels forming and dissipating occasionally.  We decided to call off the chase once we reached O'Neill, since it was impossible to get to the other side of the storm (we would of had to driven underneath the rotating base...which would have been a foolish thing to do).

APRIL 7, 2002: 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.