MESOSCALE DISCUSSION 0557
   NWS STORM PREDICTION CENTER NORMAN OK
   0940 PM CDT FRI APR 24 2009
   
   AREAS AFFECTED...SW THROUGH NE IA...CENTRAL INTO NRN WI
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 180...
   
   VALID 250240Z - 250345Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 180
   CONTINUES.
   
   WW IS EXPECTED TO BE ALLOWED TO EXPIRE AS SCHEDULED AT 04Z.
   
   LOW LEVEL MOISTURE/WARM AIR ADVECTION REGIME ALONG NOSE OF 50+ KT
   SSWLY LLJ EXTENDING INTO NERN KS TO SRN IA BENEATH UPPER LEVEL
   DIFFLUENT FLOW IS EXPECTED TO MAINTAIN THE TSTM COMPLEXES MOVING EWD
   DURING THE MID-LATE EVENING INTO FAR NWRN/NRN MO AND SRN IA.  THIS
   ACTIVITY SHOULD CONTINUE TO BECOME MORE ELEVATED WITH TIME AS
   SURFACE COOLING INCREASES SURFACE BASED INHIBITION.  STEEP MID LEVEL
   LAPSE RATES WILL SUPPORT A THREAT FOR HAIL WITH THE STRONGER
   STORMS...BUT STRONGER EFFECTIVE BULK SHEAR TENDING TO REMAIN IN THE
   POST FRONTAL ENVIRONMENT SUGGESTS STORMS SHOULD BECOME LESS
   ORGANIZED WITH EWD EXTENT.
   
   FARTHER NE INTO WI...DECREASING INSTABILITY/INCREASING SURFACE BASED
   INHIBITION SUGGESTS THE OVERALL SEVERE WEATHER THREAT SHOULD
   CONTINUE TO DIMINISH DURING THE NEXT FEW HOURS...AS INDICATED BY
   LATEST REGIONAL RADAR TRENDS.
   
   ..PETERS.. 04/25/2009
   
   
   ATTN...WFO...MQT...GRB...MKX...DVN...DLH...ARX...MPX...DMX...
   EAX...OAX...
   
   LAT...LON   40389591 41529458 42909311 43469263 44169254 45219158
               45699123 46278975 45718776 44988748 44108870 43269059
               42449148 41629296 40769430 40389591