MESOSCALE DISCUSSION 0745
   NWS STORM PREDICTION CENTER NORMAN OK
   0420 AM CDT TUE MAY 21 2013
   
   AREAS AFFECTED...PART OF SRN/ERN OK INTO WEST CENTRAL AR
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 199...
   
   VALID 210920Z - 211015Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 199
   CONTINUES.
   
   SUMMARY...AN ISOLATED HAIL THREAT CONTINUES ACROSS WW 199 INTO THE
   EARLY MORNING...AS NEW STORMS DEVELOP FROM KIOWA COUNTY OK THROUGH
   CENTRAL MCCLAIN/SRN CLEVELAND COUNTIES TO MCINTOSH COUNTY OK.
   
   DISCUSSION...A BROAD WAA ZONE EXTENDING INTO SRN OK WITHIN THE NOSE
   OF A 45-50 KT SSWLY LLJ COMBINED WITH A NWD INFLUX OF MODERATE
   INSTABILITY SUGGESTS TSTM DEVELOPMENT WILL CONTINUE FROM W-E ACROSS
   WW 199.  EFFECTIVE BULK SHEAR UP TO 50 KT SUPPORTS STORM
   ORGANIZATION.  THESE FACTORS COMBINED WITH STEEP MIDLEVEL LAPSE
   RATES OF 7.5-8 C/KM PER OBJECTIVE ANALYSES WILL FAVOR A CONTINUED
   POTENTIAL FOR ADDITIONAL STRONGER STORMS TO PRODUCE PRIMARILY A HAIL
   THREAT.
   
   SINCE 0840Z...REGIONAL RADAR IMAGERY INDICATED AN INCREASE IN TSTM
   DEVELOPMENT FROM CENTRAL MCCLAIN COUNTY OK TO CENTRAL AND ERN KIOWA
   COUNTY OK.  THESE STORMS APPEAR TO BE FORMING ALONG A COLD FRONT
   ADVANCING SWD INTO CENTRAL AND SWRN OK WHERE THE INFLOW OF MODERATE
   INSTABILITY IS SUPPORTING THIS NEW DEVELOPMENT.
   
   ..PETERS.. 05/21/2013
   
   
   ATTN...WFO...LZK...SHV...TSA...OUN...
   
   LAT...LON   34109762 34319816 34829893 35009855 35159766 35369712
               35369628 35869562 35769372 35299379 34669450 34539455
               34119526 34049714 34109762