SPC MESOSCALE DISCUSSION 2040 FOR NWRN TX..ERN TX PANHANDLE..WRN OK
CONCERNING...SEVERE THUNDERSTORM WATCH 745...

VALID 202230Z - 210100Z

PERSISTENT SUPERCELL CONTINUES TO MOVE SLOWLY SWD OVER COTTLE
COUNTY/TX ATTM...JUST WEST OF RESIDUAL OUTFLOW BOUNDARY ARCING NWD
FROM N OF BGS TO NEAR THE OK/TX PANHANDLE BORDER.  VWP FROM KFDR
AND JTN PROFILER BOTH INDICATE FAVORABLE LOW LEVEL SHEAR/HELICITY
AND MID LEVEL SR-FLOW FOR ISOLATED TORNADOES WITH THIS CELL GIVEN
THE SLOW SWD MOTION.  FLASH FLOODING WILL ALSO REMAIN A DISTINCT
POSSIBILITY GIVEN THE VERY MOIST/UNSTABLE AIR MASS AND SLOW CELL
MOTIONS.

OTHER STORMS CONTINUE TO DEVELOP QUICKLY INVOF NE-SW ORIENTED
SURFACE TROUGH FROM CENTRAL KS INTO THE TX PANHANDLE...WHICH THE
ETAKF AND RUC SUGGEST WILL INCREASE OVER THE NEXT FEW HOURS.  CAPE
REMAINS IN THE MODERATE TO STRONG RANGE ACROSS THE REGION...WITH
FAVORABLE DEEP LAYER SHEAR FOR FURTHER SEVERE THUNDERSTORM
DEVELOPMENT.

ADDITIONAL WW WILL BE ISSUED SOON TO THE SOUTH OF CURRENT WW WHERE
STORMS WILL INCREASE AHEAD OF APPROACHING SHORTWAVE TROUGH AND
WITHIN LOW LEVEL WAA REGIME LATER THIS EVENING.

..EVANS.. 09/20/01