MESOSCALE DISCUSSION 2344
   NWS STORM PREDICTION CENTER NORMAN OK
   0525 PM CST SUN NOV 20 2011
   
   AREAS AFFECTED...NERN TX TO CNTRL AR
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 893...
   
   VALID 202325Z - 210100Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 893
   CONTINUES.
   
   THREAT FOR MARGINAL SEVERE HAIL MAY DEVELOP AS TSTM COVERAGE LIKELY
   GROWS FROM NERN TX TOWARDS CNTRL AR THIS EVENING. THE PROBABILITY OF
   A DOWNSTREAM SEVERE TSTM WATCH ISSUANCE BY 01Z IS 20 PERCENT.
   
   23Z SURFACE ANALYSIS PLACED A MESOLOW NEAR CRS WITH A SLOW MOVING
   COLD FRONT EXTENDING NEWD INTO N-CNTRL AR. DESPITE THE PRESENCE OF
   MODERATE BUOYANCY WITH MLCAPE AROUND 1000 TO 1500 J/KG...INITIAL
   CLUSTER OF TSTMS NE OF THE MESOLOW HAVE STRUGGLED TO STRENGTHEN.
   THIS MAY BE A RESULT OF STRONG WLYS BEING CONFINED TO AOA 5 KM AGL
   /PER DE QUEEN AR PROFILER/...ALONG WITH POOR LAPSE RATES AND WEAK
   RIDGING IN THE HIGH-LEVELS. ALTHOUGH A RELATIVELY TIGHT THERMAL
   GRADIENT EXISTS WITHIN THE FRONTAL ZONE...ANEMIC SURFACE WINDS
   SHOULD LIMIT CONVERGENCE. EVEN SO...ISENTROPIC LIFT OWING TO A
   MODEST 20-30 KT LLJ SHOULD BE SUFFICIENT FOR AN INCREASE IN TSTM
   COVERAGE INTO AR THIS EVENING...POTENTIALLY PRODUCING MARGINAL
   SEVERE HAIL.
   
   ..GRAMS.. 11/20/2011
   
   
   ATTN...WFO...LZK...SHV...TSA...FWD...
   
   LAT...LON   31899751 33289605 34529435 35499333 35789247 35649191
               34749206 33589301 32869410 31639641 31429713 31899751