MESOSCALE DISCUSSION 0250
   NWS STORM PREDICTION CENTER NORMAN OK
   0533 PM CDT TUE MAR 22 2011
   
   AREAS AFFECTED...SWRN IA...ERN KS AND WRN MO
   
   CONCERNING...TORNADO WATCH 53...
   
   VALID 222233Z - 222330Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 53 CONTINUES.
   
   GREATEST THREAT FOR TORNADOES IS EXPECTED TO REMAIN ACROSS
   SWRN-SCNTRL IA EARLY THIS EVENING. ISOLATED SUPERCELLS COULD ALSO
   DEVELOP FARTHER SW ACROSS ERN KS INTO NWRN MO POSING A THREAT FOR
   LARGE HAIL AND ISOLATED TORNADOES.
   
   DEEP SURFACE LOW WAS SITUATED OVER THE NEB/IA BORDER NEAR OMAHA. A
   DRYLINE EXTENDS SWD FROM THE LOW THROUGH SERN NEB INTO ERN KS...WITH
   A WARM FRONT STRETCHING EWD THROUGH SRN IA INTO NCNTRL IL. A PACIFIC
   COLD FRONT EXTENDS FARTHER W FROM SERN NEB INTO N-CNTRL AND SWRN
   KS...AND THIS BOUNDARY SHOULD EVENTUALLY MERGE WITH THE DRYLINE.
   UNSTABLE WARM SECTOR IS QUITE NARROW WITH ZONE OF 1000-1500 J/KG
   MLCAPE FROM ERN KS...WRN MO AND SWRN IA. STRONG PRESSURE FALLS ARE
   OCCURRING EAST OF SURFACE LOW ACROSS SWRN IA IN RESPONSE TO DEEPER
   ASCENT WITHIN EJECTING UPPER JET EXIT REGION. GREATEST TORNADO
   THREAT WILL LIKELY PERSIST ACROSS SWRN-SCNTRL IA NEXT COUPLE HOURS
   AS STORMS THAT DEVELOP ALONG DRYLINE LIFT NEWD AND INTERACT WITH
   WARM FRONT WHERE 0-1 KM STORM RELATIVE HELICITY IS MAXIMIZED. STORMS
   WILL SUBSEQUENTLY BECOME ELEVATED AS THEY MOVE DEEPER INTO THE COOL
   SECTOR...BUT COULD STILL POSE A THREAT FOR ISOLATED LARGE HAIL.
   
   STORMS COVERAGE WILL REMAIN ISOLATED WITH SWD EXTENT THROUGH ERN KS
   AND WRN MO WHERE DEEPER FORCING IS MORE LIMITED AND CAP WILL LIKELY
   REMAIN STRONGER.
   
   ..DIAL.. 03/22/2011
   
   
   ATTN...WFO...DMX...OAX...
   
   LAT...LON   40689460 41149532 41769604 41899512 41389394 40689460