MESOSCALE DISCUSSION 0565
   NWS STORM PREDICTION CENTER NORMAN OK
   0349 PM CDT SAT APR 25 2009
   
   AREAS AFFECTED...EASTERN TX PANHANDLE...WESTERN OK AND SOUTH-CENTRAL
   KS
   
   CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 
   
   VALID 252049Z - 252245Z
   
   UPDATE TO EARLIER DISCUSSION.
   
   RADAR/SATELLITE INDICATE THE STALLED FRONT HAS BEGUN A VERY SLOW
   RETREAT NWD THROUGH THE TX PANHANDLE AND NORTHWEST OK WHILE THE
   DRYLINE WAS MIXING EWD TO ARMSTRONG TO CROSBY COUNTIES IN TX. 
   TOWERING CU WAS BUBBLING AT THE INTERSECTION OF THE TWO OVER
   SOUTHWEST GRAY COUNTY TX...IN THE FREE WARM SECTOR OVER WCENTRAL OK
   AND NORTHEAST ALONG THE FRONT.
   
   LARGER SCALE ASCENT WILL IMPROVE AFTER 22Z IN WAKE OF THE EARLIER
   DISTURBANCE MOVING INTO EASTERN KS PER WATER VAPOR IMAGERY.  THIS
   WILL ACT TO DEEPEN THE DRYLINE/FRONTAL CIRCULATION AND INITIATION
   STILL LOOKS TO BE ACROSS THE EASTERN TX PANHANDLE...NORTHEAST ALONG
   THE FRONT INTO WEST-CENTRAL/NORTHWEST OK IN AN HOUR OR TWO /ASIDE
   FROM ACTIVITY DEVELOPING IN CNTRL/ERN KS/.  MODIFYING THE 20Z NORMAN
   SOUNDING FOR A 88/58 AIR PARCEL SUGGESTS VERY LITTLE CAP AND MLCAPES
   OF OVER 2000 J/KG.  CORRIDOR FROM JERICHO-TURKEY TX NORTHEAST ACROSS
   ERICK...ELK CITY...CLINTON...WATONGA AND ENID NORTH TO JUST NW OF
   THE FRONT WILL HAVE THE HIGHEST SEVERE PROBABILITIES THROUGH EARLY
   EVENING.
   
   REMAINDER OF THE BELOW DISCUSSION STILL VALID.
   
   SOMEWHAT ANEMIC VERTICAL SHEAR PROFILES NOTED CURRENTLY SHOULD
   IMPROVE BY INITIATION TIME AS STRONGER SOUTHWESTERLY MID-LEVEL WINDS
   OVER THE SOUTHERN ROCKIES EDGE SOUTHEASTWARD.  WIND PROFILES WILL
   BECOME VERY CONDUCIVE FOR SUPERCELLS WITH GIANT HAIL GREATER THAN 2
   INCHES IN DIAMETER.  IN FACT...AS THE GREAT BASIN UPPER TROUGH
   CONTINUES TOWARD THE SOUTHERN ROCKIES...SOUTHERLY BOUNDARY LAYER
   FLOW IS EXPECTED TO INCREASE TO OVER 55 KTS DURING THE EVENING. 
   THIS WILL NOT ONLY MAINTAIN DISCRETE SUPERCELL STRUCTURES AS RICH
   MOISTURE INFLOW CONTINUES...BUT ALSO BOOST 0-1KM STORM RELATIVE
   HELICITY TO AT OR ABOVE 400 M2/S2.  THIS WILL LIKELY YIELD
   LONG-LIVED SUPERCELLS WITH POSSIBLE STRONG TORNADOES WHICH MAY LAST
   WELL BEYOND SUNSET ACROSS WEST-CENTRAL/ NORTH-CENTRAL OK INTO
   SOUTH-CENTRAL KS.
   
   ..RACY.. 04/25/2009
   
   
   ATTN...WFO...ICT...OUN...DDC...LUB...AMA...
   
   LAT...LON   34260079 35560082 37729774 37779705 36049761 34379845
               34259973 34260079