MESOSCALE DISCUSSION 0839
   NWS STORM PREDICTION CENTER NORMAN OK
   0236 PM CDT SAT MAY 19 2012
   
   AREAS AFFECTED...NWRN OK THROUGH CNTRL KS INTO SERN NEB AND SWRN IA
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 191936Z - 192100Z
   
   PROBABILITY OF WATCH ISSUANCE...95 PERCENT
   
   SUMMARY...INITIAL STORMS ARE EXPECTED TO DEVELOP 21-22Z FROM PARTS
   OF CNTRL KS INTO ERN NEB. ADDITIONAL STORMS MAY DEVELOP A LITTLE
   LATER FARTHER SOUTH FROM SCNTRL KS INTO NWRN OK. POTENTIAL WILL
   EXIST FOR BOTH SUPERCELLS AND BOWING LINE SEGMENTS WITH LARGE HAIL
   AND DAMAGING WIND THE MAIN THREATS.
   
   DISCUSSION...A COLD FRONT EXTENDS ACROSS ERN NEB SWWD THROUGH WCNTRL
   KS INTO THE OK AND TX PANHANDLES. A DRYLINE STRETCHES FROM WRN TX
   NWD INTO SWRN KS WHERE IT INTERSECTS THE COLD FRONT. THE WARM SECTOR
   HAS BECOME MODERATELY UNSTABLE WITH 1500-2000 J/KG MLCAPE BASED ON
   LATEST OBJECTIVE ANALYSIS...BUT IS STRONGLY CAPPED BY A WARM EML
   THAT HAS ADVECTED INTO THIS REGION. SATELLITE IMAGERY INDICATES A
   BAND OF MID-HIGH LEVEL CLOUDS ADVANCING THROUGH WRN KS AND MAY BE
   INDICATIVE OF THE LEADING EDGE OF MID LEVEL ASCENT ASSOCIATED WITH
   AN UPPER JET STREAK ROUNDING BASE OF SHORTWAVE TROUGH. THE CAP WILL
   WEAKEN AS THE ARRIVAL OF DEEPER ASCENT OVERTAKES THE WRN EDGE OF
   WARM SECTOR. STORMS ARE EXPECTED TO DEVELOP WITHIN THE ZONE OF
   MESOSCALE FORCING ALONG THE FRONT BY 21-22Z MOST LIKELY FROM CNTRL
   KS THROUGH ERN NEB. BOUNDARY LAYER MOISTURE IS MODEST WITH UPPER 50S
   DEWPOINTS AND TEMPERATURES CLIMBING INTO THE UPPER 80S PROMOTING
   LARGE BOUNDARY LAYER TEMPERATURE-DEWPOINT SPREADS. DEEP SHEAR HAS
   INCREASED TO 40-50 KT IN FRONTAL ZONE SUPPORTIVE OF SUPERCELLS...BUT
   THE RELATIVELY DRY SUB CLOUD LAYER SUGGESTS STORMS WILL LIKELY
   BECOME OUTFLOW DOMINANT WITH DAMAGING WIND AND LARGE HAIL THE MAIN
   THREATS. ADDITIONAL MORE ISOLATED ACTIVITY MAY DEVELOP ALONG THE
   DRYLINE FARTHER SOUTH INTO NWRN OK AFTER 22Z.
   
   ..DIAL/WEISS.. 05/19/2012
   
   
   ATTN...WFO...EAX...OAX...TOP...ICT...OUN...GID...DDC...
   
   LAT...LON   41169518 37579718 36049853 36379943 37629951 38719914
               39579882 40199840 40749785 41139737 41859598 41169518