MESOSCALE DISCUSSION 0506
   NWS STORM PREDICTION CENTER NORMAN OK
   0753 PM CDT FRI APR 17 2009
   
   AREAS AFFECTED...NWRN PARTS OF N TX / ERN TX PANHANDLE / WRN OK /
   SWRN KS
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 163...
   
   VALID 180053Z - 180200Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 163
   CONTINUES.
   
   STORMS WILL GENERALLY REMAIN CONFINED TO AREAS IMMEDIATELY ADJACENT
   TO DRYLINE/OCCLUDED FRONT WHERE BEST RESERVOIR OF
   INSTABILITY/MOISTURE RESIDES.  PRIOR TO STORMS WEAKENING DUE IN
   LARGE PART TO LOSS OF DAYTIME HEATING...ISOLD LARGE HAIL WILL BE THE
   PRIMARY THREAT WITH THE MOST INTENSE STORMS.
   
   LATEST SURFACE ANALYSIS AND RADAR IMAGERY SHOW A WELL DEFINED
   DRYLINE/OCCLUDED FRONT ARCING NW-SE FROM SERN CO TO THE LOW ROLLING
   PLAINS OF NWRN TX WITH WWD MOVING OUTFLOW BOUNDARY FROM EARLIER
   CONVECTION ACROSS N-CNTRL TX SURGING W AND MERGING WITH LARGER-SCALE
   FEATURE OVER PARTS OF TX.  DESPITE MODEST CONVECTIVE INSTABILITY
   /MLCAPE VALUES AOB 500 J/KG/ ACCORDING TO OBJECTIVE ANALYSIS FIELDS
   WITHIN A NARROW ZONE ALONG AND JUST E OF BOUNDARY...STRONG 0-6 KM IN
   EXCESS OF 75 KTS SAMPLED BY 00Z AMA RAOB WILL SUPPORT ORGANIZED
   STORMS IN THE NEAR TERM AS LOW LEVEL CONVERGENCE AND INCREASING
   LARGE SCALE ASCENT ASSOCIATED ERN NM/NWRN TX S/W TROUGH CONTINUES TO
   OVERSPREAD INSTABILITY AXIS.  AS SUCH...EXPECTING SEVERE THREAT TO
   MAINLY CONSIST OF ISOLD LARGE HAIL THE NEXT HR OR TWO BEFORE
   WEAKENING LOW LEVEL CONVERGENCE AND INCREASING CINH LEAD TO A MORE
   SUBDUED THREAT.
   
   ..SMITH.. 04/18/2009
   
   
   ATTN...WFO...GLD...PUB...BOU...
   
   LAT...LON   37910221 38470322 38460388 38550445 38710455 38880443
               39060335 38610230 38140208 37910221