MESOSCALE DISCUSSION 0551
   NWS STORM PREDICTION CENTER NORMAN OK
   0925 PM CDT MON APR 22 2013
   
   AREAS AFFECTED...NW OK AND S CENTRAL KS
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 136...
   
   VALID 230225Z - 230400Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 136
   CONTINUES.
   
   SUMMARY...ONGOING SUPERCELLS MAY GRADUALLY WEAKEN BY 03-04Z AS THEY
   APPROACH THE EDGE OF THE WATCH IN CENTRAL OK...THOUGH WILL MONITOR
   FOR POSSIBILITY OF A LOCAL EXTENSION OF A FEW COUNTIES AND 1-2
   HOURS...IF NEEDED.
   
   DISCUSSION...THE ONGOING SUPERCELLS ACROSS CUSTER AND GRANT COUNTIES
   IN OK HAVE LIKELY PASSED PEAK INTENSITY AS THE BOUNDARY LAYER
   DOWNSTREAM FROM THE STORMS COOLS AND CONVECTIVE INHIBITION
   INCREASES.  THUS...IN THE ABSENCE OF A LARGE LOW-LEVEL MOISTURE
   SURGE INTO THIS AREA AS THE LLJ STRENGTHENS...IT APPEARS THE THREAT
   FOR LARGE HAIL AND DAMAGING WINDS SHOULD DIMINISH GRADUALLY THROUGH
   03-04Z.  AT THIS TIME...A NEW WATCH FOR CENTRAL OK DOES NOT APPEAR
   NECESSARY.  A SMALL PART OF W CENTRAL/CENTRAL OK WILL CONTINUE TO BE
   MONITORED FOR A THE POSSIBILITY OF A LOCAL EXTENSION IN TIME/SPACE
   IF THE SRN SUPERCELL DOES NOT WEAKEN AS EXPECTED.  ALSO...THERE WILL
   BE SOME POSSIBILITY OF UPSCALE GROWTH OF CONVECTION INTO A
   CLUSTER...THOUGH THE SEVERE WEATHER RISK INTO CENTRAL OK WILL BE
   TEMPERED BY INCREASINGLY MARGINAL INSTABILITY.
   
   ..THOMPSON.. 04/23/2013
   
   
   ATTN...WFO...TSA...ICT...OUN...
   
   LAT...LON   36189713 35739772 35399856 35369953 35519987 35689968
               36009892 36939808 37599734 37809687 37729649 37179653
               36539684 36189713