MESOSCALE DISCUSSION 0700
   NWS STORM PREDICTION CENTER NORMAN OK
   0357 PM CDT SUN MAY 08 2011
   
   AREAS AFFECTED...PORTIONS OF SWRN OK AND WRN PORTIONS OF NORTH TX
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 082057Z - 082300Z
   
   AN ISOLATED SVR STORM OR TWO COULD DEVELOP ACROSS PORTIONS OF SWRN
   OK AND WRN PORTIONS OF NORTH TX.
   
   A DRYLINE CONTINUES TO SHARPEN FROM CNTRL OK INTO WRN PORTIONS OF
   NORTH TX...EXTENDING FROM 15 W CHK TO THE RED RIVER 20 W SPS TO 25
   ENE SJT AND FARTHER SW INTO SWRN TX. A BROAD MOIST SECTOR EXISTS
   EAST OF THE DRYLINE WHERE SFC DEWPOINTS ARE IN THE MIDDLE 60S TO
   NEAR 70. OVERLAYING THIS MOISTURE...VERY STEEP MID-LEVEL LAPSE RATES
   /APPROACHING DRY ADIABATIC PER 12Z OBSERVED SOUNDINGS AT KOUN AND
   KDDC/ IN ASSOCIATION WITH THE STRONG ELEVATED MIXED-LAYER ARE
   CONTRIBUTING TO A VERY UNSTABLE AIR MASS EAST OF THE DRYLINE /MLCAPE
   VALUES AOA 3000 J PER KG/. THUS FAR...STRONG CAPPING EAST OF THE
   DRYLINE IS SUPPRESSING THE DEVELOPMENT.
   
   CONTINUED STRONG INSOLATION OVER THE WRN PERIPHERY OF THE RICH
   MOISTURE AXIS AND ERN PERIPHERY OF THE THERMAL AXIS COULD REDUCE
   CONVECTIVE INHIBITION SUFFICIENTLY TO SUPPORT THE DEVELOPMENT OF A
   THUNDERSTORM OR TWO ALONG AND IMMEDIATELY EAST OF THE DRYLINE. THERE
   IS MUCH UNCERTAINTY IN THIS POTENTIAL...OWING TO LACK OF SUPPORT
   FROM CONVECTIVE-ALLOWING MODELS AND UNCERTAINTY IN THE DEGREE OF
   SUPPRESSION OF CONVECTIVE INHIBITION. HOWEVER...THE PRESENCE OF A
   DEVELOPING CUMULUS FIELD NEAR THE DRYLINE...WHERE ENHANCED
   CONVERGENCE IS PRESENT AND RAPID REFRESH FORECAST SOUNDINGS INDICATE
   CONVECTIVE INHIBITION AOB 25 J/KG...LEND CREDENCE TO THIS THREAT
   /ALBEIT SMALL/.
   
   ANY STORM THAT FORMS COULD QUICKLY BECOME SEVERE...GIVEN THE DEGREE
   OF POTENTIAL UPWARD BUOYANCY PREVIOUSLY MENTIONED. WHILE
   LOW/MID-LEVEL FLOW IS NOT PARTICULARLY IMPRESSIVE...MODERATE
   UPPER-LEVEL FLOW COUPLED WITH LARGE STORM DEPTHS WILL YIELD
   EFFECTIVE BULK SHEAR MAGNITUDES FROM 35 TO 40 KT TO SUPPORT
   SUPERCELLULAR STRUCTURES. THIS WILL ESPECIALLY BE THE CASE IF ANY
   STORM IS STEERED INTO THE DEEPER MOISTURE EAST OF THE DRYLINE. DMGG
   WINDS AND LARGE HAIL /POTENTIALLY VERY LARGE/ WILL BE THE MAIN
   THREATS WITH ANY STORMS. THE ABSENCE OF STRONGER LOW-LEVEL FLOW PER
   AREA VWPS IS EXPECTED TO MITIGATE THE TORNADO POTENTIAL. GIVEN THAT
   ANY FORCING FOR CONVECTION WILL LARGELY BE TIED TO THE DRYLINE
   /WHICH IS EXPECTED TO MAKE LITTLE EWD PROGRESS THROUGH THIS
   EVENING/...GIVEN THE CONVECTIVE INHIBITION EAST OF THE DRYLINE...AND
   GIVEN ONLY ISOLATED CONVECTIVE COVERAGE...THE SPATIAL EXTENT OF ANY
   SEVERE THREAT IS EXPECTED TO BE LOW.
   
   ..COHEN.. 05/08/2011
   
   
   ATTN...WFO...FWD...OUN...SJT...
   
   LAT...LON   33429790 32329846 31669960 31960020 32530008 33299963
               34299911 34759867 34949835 34929803 34809775 34219778
               33429790