saturday, may 22, 2004

 

initiation over jewell county ks

         

supercell updraft strengthens rapidly southwest through north of hebron ne

              

large tornado revealed north of alexandria ne

                  

the birth of a monster

               

route/tornado tracks and radar imagery

         

 

01Z modified sounding for Daykin-Hallam, NE (based on OAX and TOP RAOBs)

Sfc T/Td: 82/67 F

MLCAPE: 3709 J/kg

MLCINH: 2 J/kg

0-3 km MLCAPE: 109 J/kg

 

 

representative hodograph based on Fairbury profiler

storm motion: 242 deg @ 33 kts

0-1 km SRH: 509 m2/s2

0-3 km SRH: 619 m2/s2

0-1 km bulk shear: 47 kts

0-6 km bulk shear: 76 kts

7-10 km SR flow: 28 kts

 


 

Daykin-Hallam tornado track courtesy of NWSOAX

 

 

chase log:

it wasn't clear until the morning of that things could be really interesting.  several targets existed in the central plains due to the potential for various initiation mechanisms.  i chose to wait in advance of a progged dryline bulge, and it paid off.  my experience with this classically cyclic supercell, which went from clump of cumulus to tornado-producer a little over an hour, was literally hair-raising.  unfortunately, the two tornadoes i observed were not meant to be photographed due to low light and enormous amounts of rfd- and tornadic-driven dust.  the first tornado emerged as a full-fledged wedge from behind a towering wall of dirt northwest of alexandria.  intermittently defined by lightning flashes, the tornado moved north-northeast along side highway 53, eventually crossing it and dissipating shortly thereafter.  the new mesocyclone—seemingly a mirror image of the first—formed rapidly a few miles to the east, resulting in a beautiful white cone tornado just northeast of the town of daykin.  this tornado moved nearly due east and quickly became choked with dirt, taking on a wedge appearance.  scarily, the left-side wall of the low-level meso appeared to descend to ground level before the tornado dissapeared into the murk to my northeast.  the tornado would later intensify as it moved toward a more favorable low-level thermodynamic environment; it reached f4 intensity and purportedly broke the all-time record tornado width when the circulation grew to 2 ½ miles in diameter.