Friday, May 29, 2015

West Central Kansas Supercell

The final chase of a 10 day chase vacation took place in West Central Kansas on May 28th.  Wes Adkins and myself departed from Amarillo during the morning, northbound to Boise City in the Oklahoma Panhandle.  After a data check, we saw the potential for discrete thunderstorm development in the vicinity of a possible pre-existing outflow boundary over western Kansas.  We departed for this location, with a thunderstorm developing over our target during the drive north.  As we approached the base of the storm near Tribune, we spotted a cone shaped funnel extending not quite halfway to the ground.  This funnel dissipated en-route, but two separate wall clouds developed in its wake, one to the west, and one to the east.  The western wall cloud attempted to go through an occlusion, but being that it was embedded in outflow from the more dominant eastern updraft core, it soon dissipated.  We were then cut off from the eastern wall cloud due to a large rain/hail shield.  So, we drove south to Syracuse, then east beneath a second storm that was merging with the northern storm.  This complex developed into a line segment.  We followed along for a while taking pictures of a shelf cloud that spread across expansive fields of wheat.  After an hour of chasing outflow, we called it a day and headed to Garden City for dinner.

Thursday, May 28, 2015

Canadian, Texas Cyclic Tornadic Supercell

Wes Adkins and myself targeted the northeastern Texas Panhandle on May 27th, ending up near Moobetie by early afternoon.  From a road side rest stop, we watched what initially appeared to be a multicell thunderstorm initiate to our north near Canadian, TX.  This thunderstorm consolidated during the next hour, and developed a strong reflectivity gradient on its southern flank based on the Amarillo NEXRAD.  This quickly became our target storm, and we departed for Canadian.  The supercell appeared to have the potential to take a hard right toward the southeast, so we cautiously approached from the south.  However, it became obvious with time that the updraft was virtually stationary, so we entered the southern side of Canadian and watched a wall cloud evolve.  A strong area of low-level rotation developed northeast of the wall cloud, on the north side of town, and a tornado emerged within minutes.  As the tornado rotated around the northwest side of the low-level mesocyclone, it grew into a large cylindrical cone, possibly a half mile wide.  The tornado then moved along the western edge of the mesocyclone and entered its rope stage before completely dissipating.

Three separate wall clouds then developed after the tornado, each of which appeared to have tornadic potential.  The southwestern wall cloud came close to producing, but similar to the first tornado observed, an area of strong cloud base rotation developed to its northeast, went through an occlusion, and produced another tornado.  This process happened a third time, with another brief tornado being observed.  However, the third occlusion wrapped a large amount of rain cooled air into the base of the supercell, and the tornado potential finally came to an end.  We moved south of Canadian after the final occlusion took place, satisfied with the multi-hour cyclic tornadic supercell we observed.

Red River Low Precipitation Supercell

Wes Adkins and myself targeted northwest Texas on May 26th.  We parked beneath a towering cumulus southwest of Archer City during the early afternoon.  This developing cell was embedded in a cumulus deck that was slightly stratified, therefore we decided to depart for an area of stronger boundary layer destabilization near the Red River west of Wichita Falls.  This area featured a dryline outflow boundary intersection, and appeared to be a prime location for robust supercell development.  A supercell did develop, but appeared to ingest lower theta-e air from the cool side of the outflow boundary, and never managed to develop into a tornadic threat.  We parked south of the cell and watched it go through a typical LP progression, from a strongly rotating upright updraft, to a severely tilted and contracting updraft as it dissipated.

Wednesday, May 27, 2015

Supercell in Southeast Colorado and Southwestern Kansas

Wes Adkins and myself drove to southeast Colorado by noon time on May 24th, observing generally mushy looking updrafts slowly evolve to our west.  While parked in front of the entrance to a ranch, an old cowboy, by the name of Charlie Fowler, drove down his long stretch of dirt road in order to investigate why we were parked near his property.  He was friendly, and we struck up a long conversation while occasionally glancing off on the horizon at our target storm.  Eventually, Charlie offered to take us on to his ranch (officially named Fowler Cedar Cliff Ranch) and show us the historical remains of a homestead via the late 1800's.  We received a personal tour of the homestead property, which featured an old barn, sod house, and windmill, and I'm very grateful to Charlie for the warm welcome.  After an hour, we parted ways, and followed what was now an intensifying supercell that displayed 70 dBZ reflectivity values in the mid to upper levels of the storm.  Large hail was a sure bet with this cell, and we made certain to stay well ahead of its precipitation core.  Cloud to cloud lightning was constantly being produced, as well as a few CG's, and the leading edge updraft showed some helical structure from time to time.  Low-level scud eventually blocked our view of the storm after sunset, while a prolific tornado producing supercell was approaching from the southwest.  We entered Dodge City, KS immediately before the southwestern supercell merged with our bowing supercell to the west.  Tornado warnings continued to be issued for this complex as we fell asleep in our Dodge City hotel.

Monday, May 25, 2015

Supercell/Possible Tornado - Trans Pecos Region of Far West Texas

Wes Adkins and myself left Lubbock, TX during the morning of Friday May 22, drove south to Odessa, exited low stratus as we entered Fort Stockton, and then parked 20 or so miles east-northeast of the Davis Mountains in Far West Texas.  Towering cumulus struggled to breach the cap for an hour or two, and then one cell pushed through along a differential heating boundary left by the previously dissipated stratus as an orphan anvil spread northeast across the zone of ascent.  This cell back built toward the Davis Mountains, where it then became anchored to the elevated heat source.  It quickly evolved into a supercell, with the base initially shrouded in rain, but eventually becoming rain free, after-which a skinny funnel developed (but failed to make contact with the ground).  We watched this supercell sit over the Davis Mountains for another hour or two, and then departed back north toward Lubbock.