MESOSCALE DISCUSSION 0415
   NWS STORM PREDICTION CENTER NORMAN OK
   1054 AM CDT WED APR 22 2015

   AREAS AFFECTED...S TX

   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

   VALID 221554Z - 221745Z

   CORRECTED FOR TORNADO THREAT

   PROBABILITY OF WATCH ISSUANCE...60 PERCENT

   SUMMARY...STORMS WILL GRADUALLY DEVELOP OVER SRN INTO S-CNTRL TX BY
   EARLY AFTERNOON...WITH LARGE HAIL AND LOCALIZED WIND DAMAGE OR
   TORNADO. A WATCH MAY BE NEEDED.

   DISCUSSION...AN EXTREMELY MOIST AIR MASS IS EXISTS ACROSS DEEP S TX
   WITH PRECIPITABLE WATER MEASUREMENTS OF 1.75 TO 2.00 INCHES AND
   DEWPOINTS IN THE 70S F. ALTHOUGH SUBSTANTIAL HIGH CLOUD COVER
   EXISTS...SOME HEATING WILL OCCUR DUE TO BREAKS LEADING TO FURTHER
   DESTABILIZATION. 

   A SLY LOW-LEVEL JET WILL ALSO AID IN NWD TRANSPORT OF THIS MOIST AIR
   MASS INTO CNTRL TX LATER TODAY. A GRADUAL DEEPENING OF THE MOIST
   BOUNDARY LAYER...AS WELL AS POSSIBLE SUBTLE WAVES IN THE
   SUB-TROPICAL JET STREAM WILL LIKELY LEAD TO SCATTERED STRONG TO
   SEVERE STORMS BY AFTERNOON. RELATIVELY STEEP LAPSE RATES ABOVE 700
   MB AS WELL AS LONG HODOGRAPHS IN THE CLOUD-BEARING LAYER WILL
   SUPPORT HAIL. WATER LOADING MAY LEAD TO LOCALLY DAMAGING WINDS AS
   WELL WITH ANY OF THE LARGER CELLS OR CLUSTERS. LOW-LEVEL TURNING OF
   THE WINDS WITH HEIGHT AND THE VERY MOIST AIR MASS SUGGEST A
   CONDITIONAL TORNADO THREAT AS WELL.

   ..JEWELL/HART.. 04/22/2015


   ATTN...WFO...HGX...CRP...EWX...BRO...

   LAT...LON   27279734 27429942 28349983 29459972 29949911 30159716
               30119588 29939529 29539506 29039499 28559583 28219649
               27919687 27459722 27279734