MESOSCALE DISCUSSION 0589
   NWS STORM PREDICTION CENTER NORMAN OK
   0111 PM CDT TUE APR 26 2011
   
   AREAS AFFECTED...NORTHEAST TX AND FAR SOUTHEAST OK/NORTHERN
   LA/SOUTHERN AR
   
   CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 
   
   VALID 261811Z - 262015Z
   
   THE SEVERE THREAT IS EXPECTED TO STEADILY INCREASE THROUGH MID/LATE
   AFTERNOON...INITIALLY ACROSS PORTIONS OF NORTHEAST TX AND INTO
   SOUTHEAST OK/NORTHERN LA/SOUTHERN AR. A RELATIVELY LONG LEAD
   TIME/DURATION PARTICULARLY DANGEROUS SITUATION /PDS/ TORNADO WATCH
   WILL LIKELY BE ISSUED BY MID AFTERNOON.
   
   WITH SURFACE CYCLOGENESIS UNDERWAY ACROSS THE SOUTHERN HIGH
   PLAINS...THE WARM SECTOR AIRMASS...EAST OF A NEAR I-35 CENTRAL TX
   DRYLINE...AND ALONG/SOUTH OF A SLOW NORTHWARD-RETURNING
   SOUTHWEST-NORTHEAST ORIENTED FRONTAL BOUNDARY FROM THE SOUTH DFW
   METRO INTO SOUTHERN AR...HAS ALREADY BECOME MODERATE TO STRONGLY
   UNSTABLE IN THE PRESENCE OF LITTLE CINH. AFTER A BRIEF BOUT OF
   SHORTWAVE RIDGING AT MIDDAY...THE LEADING EDGE OF AN UPPER JET
   STREAK APPEARS TO HAVE REACHED THE SOUTHERN HIGH PLAINS...WITH
   LIKELY-ASSOCIATED DEEP MIXED CUMULIFORM DEVELOPMENT NOW EVIDENT
   ACROSS EASTERN NM/NORTHWEST TX PER VISIBLE SATELLITE IMAGERY.
   INCREASING DEEP LAYER WIND FIELD ATOP THE MOIST/UNSTABLE WARM SECTOR
   WILL BE HIGHLY FAVORABLE FOR SUPERCELLS WITH AN INCREASING LARGE
   HAIL/TORNADO THREAT INTO THIS EVENING. STRENGTHENING LOWER
   TROPOSPHERIC WINDS THIS EVENING WILL ACCENTUATE THE RISK OF STRONG
   TORNADOES ESPECIALLY ACROSS THE ARKLATEX VICINITY/ADJACENT FAR
   SOUTHEAST OK.
   
   ..GUYER.. 04/26/2011
   
   
   ATTN...WFO...JAN...LZK...SHV...TSA...HGX...FWD...OUN...
   
   LAT...LON   31739772 32889727 34059625 34489432 34559322 34019166
               32609213 31619336 30579640 31739772