MESOSCALE DISCUSSION 0266
   NWS STORM PREDICTION CENTER NORMAN OK
   0329 AM CDT SUN MAR 11 2007
   
   AREAS AFFECTED...SWRN OK AND NWRN TX
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 110829Z - 111000Z
   
   POTENTIAL FOR LOCALLY DAMAGING WIND GUSTS WILL EXIST WITH ONGOING
   BOWING STRUCTURE AS IT PROGRESSES EWD THROUGH SWRN OK AND NWRN TX
   EARLY THIS MORNING.  THIS THREAT IS EXPECTED TO REMAIN LIMITED BOTH
   SPATIALLY AND TEMPORALLY AND A WW IS NOT ANTICIPATED.
   
   AN ELEVATED BOWING COMPLEX /BASED BETWEEN 800-850 MB/ HAS EVOLVED
   OVER THE PAST HOUR OR SO OVER PORTIONS OF SWRN OK INTO NWRN
   TX...EXTENDING FROM KIOWA COUNTY OK SWD WILBARGER COUNTY TX AS OF
   0810Z.  RECENT MESONET OBSERVATION IN JACKSON COUNTY OK INDICATED A
   WIND GUST TO 67 MPH...WITH ESTIMATED REPORTS OF WINDS TO 80 MPH IN
   QUANAH TEXAS.
   
   INSPECTION OF LONGER MOSAIC RADAR LOOP INDICATES THAT THIS SYSTEM IS
   PERHAPS ASSOCIATED WITH AN INTENSIFYING MCV OVER HARMON AND GREER
   COUNTIES IN FAR SWRN OK.  RUC PROXIMITY SOUNDINGS SUGGEST THAT
   ELEVATED MOIST LAYER AROUND 850-800 MB COUPLED WITH MODERATELY STEEP
   MID-LEVEL LAPSE RATES ARE CONTRIBUTING TO A WEAKLY UNSTABLE AMBIENT
   ENVIRONMENT WITH MUCAPES OF 500-600 J/KG.  MOREOVER...PRONOUNCED DRY
   LAYER FROM 750-600 MB IS RESULTING IN FAIRLY SIZABLE DCAPE VALUES OF
   800-900 J/KG.  THIS POTENTIAL DOWNDRAFT INSTABILITY IN CONJUNCTION
   WITH NEARLY 1.5 KM DEEP DRY BOUNDARY LAYER ARE LIKELY RESPONSIBLE
   FOR THE STRONG DOWNDRAFTS BEING OBSERVED.
   
   CURRENT SURFACE OBSERVATIONS SUGGEST THAT DAMAGING WINDS ARE
   OCCURRING WITHIN AN ENVIRONMENT CHARACTERIZED BY TEMPERATURES OF
   AROUND 60 F AND DEWPOINTS OF AROUND 40 F.  BOUNDARY LAYER BECOMES
   PROGRESSIVELY MORE MOIST WITH EWD EXTENT TOWARD I-35 WITH
   TEMPERATURE-DEWPOINT SPREADS DECREASING TO 10-15 F.  AS SUCH...IT
   APPEARS THAT EVAPORATIVE COOLING AND RESULTANT DAMAGING WIND THREAT
   MAY TEND TO DIMINISH AS BOWING STRUCTURE CONTINUES EWD THIS MORNING.
   
   ..MEAD.. 03/11/2007
   
   
   ATTN...WFO...FWD...OUN...
   
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