MESOSCALE DISCUSSION 0726
   NWS STORM PREDICTION CENTER NORMAN OK
   0305 AM CDT WED MAY 06 2009
   
   AREAS AFFECTED...PORTIONS EXTREME SERN OK...SRN AR...EXTREME NE
   TX...NRN MS S OF COUNTIES STILL IN WW 248...AND PARTS OF
   W-CENTRAL/NWRN AL.
   
   CONCERNING...TORNADO WATCH 250...
   
   VALID 060805Z - 061000Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 250 CONTINUES.
   
   PRIMARY MCS WAS EVIDENT AT 745Z FROM NRN MCCURTAIN COUNTY OK ESEWD
   OVER PBF AREA.  ERN SEGMENT OF MCS APCHG MS RIVER IS ALIGNED MORE
   PERPENDICULAR TO MEAN FLOW...AND ACCORDINGLY IS ASSUMING BOW ECHO
   CHARACTERISTICS.  INCREASING THREAT OF DAMAGING WIND EXISTS AS THIS
   ACTIVITY ACCELERATES ESEWD OVER NRN MS...ESPECIALLY THAT CORRIDOR
   OVER NRN PORTION OF WARM FRONTAL ZONE FROM COAHOMA COUNTY TOWARD CBM
   AREA.  THIS CONVECTION WILL ENCOUNTER FAVORABLY MOIST/UNSTABLE AIR
   MASS ALONG SUCH PATH.  EFFECTIVE LIFTED PARCELS WILL BE ROOTED AT OR
   JUST ABOVE SFC...NOT ACCOUNTING FOR FORCED ASCENT ALONG COLD POOL. 
   SFC MESOANALYSIS ALSO SHOWS SRN RIM OF ISALLOBARIC FALL ZONE OVER
   THIS REGION...LEADING TO BACKED SFC WINDS THAT...IN TURN...ENHANCES
   STORM-RELATIVE INFLOW AND SRH FOR ANY AIR THAT CAN BE HOISTED TO LFC
   ALONG LEADING EDGE OF BOWING SEGMENT.  
   
   SVR THREAT EWD OVER ADJACENT PORTIONS AL APPEARS MRGL AND MAINLY IN
   FORM OF HAIL DURING NEXT 1-2 HOURS -- FROM WHAT IS LEFT OF
   LEADING/ERN MCS.  HOWEVER...BOWING SEGMENT OF WRN MCS MAY CONTRIBUTE
   TO NEED FOR ADDITIONAL WW BEFORE 11Z EXPIRATION TIME OF THIS
   ONE...AND IT COULD INCLUDE SOME OF AL.
   
   IN ADDITION TO THREAT FOR SVR...TRAINING ECHOES ALONG TRAILING
   PORTION OF THIS MCS WILL POSE DISTINCT HAZARD FROM REPEATED HITS OF
   HEAVY RAIN DURING NEXT FEW HOURS...REF MESOSCALE DISCUSSION 723 FOR
   MORE DETAILS ON THAT THREAT.
   
   ..EDWARDS.. 05/06/2009
   
   
   ATTN...WFO...BMX...HUN...MEG...JAN...LZK...SHV...TSA...
   
   LAT...LON   33208906 33179064 33109388 33409527 33949518 34519510
               34499446 34239138 34469104 34729106 34388806 33488679
               32888775 33208906