SPC AC 260553
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1153 PM CST FRI FEB 25 2005
   
   VALID 261200Z - 271200Z
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM DRT SEP PRX ELD 45
   ESE LUL 15 SSE AQQ.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 50 WSW FHU GBN 50 WSW
   EED BIH 35 E SAC SVE LOL U31 35 NW MLF PUC GJT 10 NE 4SL 4CR CNM 65
   SSW P07.
   
   ...NO SVR TSTM AREAS FORECAST...
   
   BUILDING UPPER RIDGE IS ALREADY EVIDENT OFF THE PACIFIC NORTHWEST/
   BRITISH COLUMBIA COAST...AND RE-AMPLIFICATION OF NORTHERN BRANCH
   RIDGE WILL CONTINUE THROUGH THIS FORECAST PERIOD...AS DOWNSTREAM
   SHORT WAVE TROUGH CLEARS THE CANADIAN ROCKIES. LATTER FEATURE IS
   PROGGED TO DIG SOUTH SOUTHEASTWARD INTO THE VICINITY OF THE CENTRAL
   CANADIAN/U.S. BORDER BY 12Z SUNDAY.  AS THIS OCCURS...MODELS SUGGEST
   BROADER SCALE TROUGH IN SOUTHERN BRANCH OF POLAR WESTERLIES AND
   SUBTROPICAL WESTERLIES WILL FINALLY DEVELOP EASTWARD OUT OF THE
   SOUTHWESTERN U.S./NORTHERN MEXICAN PLATEAU INTO THE SOUTH CENTRAL
   STATES/WESTERN GULF OF MEXICO.
   
   INTERACTING IMPULSES EMBEDDED WITHIN SOUTHERN/SUBTROPICAL STREAMS
   APPEAR TO BE A SIGNIFICANT SOURCE OF MODEL VARIABILITY...
   PARTICULARLY WITH REGARD TO SURFACE DEVELOPMENTS OVER THE WESTERN
   GULF OF MEXICO...AND AREAS NEAR THE WESTERN GULF COAST.  LATEST NAM
   RUN FORECASTS STRONGER SURFACE LOW DEVELOPMENT ALONG TEXAS COASTAL
   AREAS LATER TODAY/TONIGHT THAN THE GFS.  THIS APPEARS TO OCCUR ON
   NORTHERN EDGE OF INVERTED TROUGH EXTENDING NORTHWARD FROM PRIMARY
   SURFACE CYCLONE...WHICH SHOULD FORM ALONG SURFACE BAROCLINIC ZONE
   EXTENDING ACROSS THE SOUTH CENTRAL/SOUTHWESTERN GULF OF MEXICO.
   
   EVEN IF NAM VERIFIES CLOSER THAN GFS...CURRENT STATE OF BOUNDARY
   LAYER OVER THE WESTERN GULF OF MEXICO SUGGESTS MINIMAL SEVERE THREAT
   DURING THIS FORECAST PERIOD.  DEW POINTS ARE CURRENTLY IN THE
   LOWER/MID 50S ACROSS THIS REGION...AND SUBSTANTIAL MODIFICATION DOES
   NOT APPEAR LIKELY TO OCCUR EVEN IN COASTAL WATERS OF TEXAS/LOUISIANA
   THROUGH AT LEAST EARLY SUNDAY.
   
   ...TEXAS/LOUISIANA...
   MID/UPPER MOISTURE ADVECTION OFF THE SUBTROPICAL PACIFIC...ACROSS
   THE MEXICAN PLATEAU...INTO THE LOWER RIO GRANDE VALLEY IS ONGOING. 
   AS EXIT REGION OF APPROACHING MID-LEVEL JET STREAK APPROACHES THE
   LOWER RIO GRANDE VALLEY BY DAYBREAK...LAPSE RATES ABOVE STABLE
   SURFACE-BASED LAYER MAY STEEPEN SUFFICIENTLY FOR THUNDERSTORM
   ACTIVITY INTO PARTS OF SOUTH CENTRAL/DEEP SOUTH TEXAS. 
   
   DEVELOPING RAIN SHIELD...WITH POSSIBLE CONTINUING EMBEDDED
   THUNDERSTORMS...IS THEN EXPECTED TO SLOWLY SPREAD NORTHEASTWARD
   TOWARD THE LOWER MISSISSIPPI VALLEY.  IN THE WAKE OF THIS
   ACTIVITY...ADDITIONAL SCATTERED THUNDERSTORMS APPEAR POSSIBLE IN
   STRONGER LOW-LEVEL WARM ADVECTION REGIME NEAR TEXAS COASTAL AREAS. 
   THIS MAY OCCUR LATER TODAY/TONIGHT AS SOMEWHAT BETTER LOW-LEVEL
   MOISTURE RETURNS FROM THE SOUTHWESTERN GULF...ABOVE FRONTAL
   INVERSION.
   
   ...GREAT BASIN/SOUTHERN PLATEAU/SOUTHERN ROCKIES...
   BEFORE MID-LEVEL COLD POOL SHIFTS EASTWARD...SCATTERED THUNDERSTORMS
   APPEAR LIKELY TODAY ACROSS THE HIGHER TERRAIN...PRIMARILY IN
   RESPONSE TO DAYTIME HEATING/OROGRAPHIC FORCING.
   
   ..KERR.. 02/26/2005
   
   ...NOTICE...
   FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
   LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
   GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
   HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
   INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
   
   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z