SPC AC 210029

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0729 PM CDT FRI SEP 20 2013

   VALID 210100Z - 211200Z

   ...NO SVR TSTM AREAS FORECAST...

   ...TX COASTAL PLAINS TO THE CNTRL GULF STATES...

   VERY MOIST AIRMASS RESIDES ACROSS THE UPPER TX COAST INTO MS WHERE
   PW VALUES RANGE FROM 2-2.5 INCHES.  REMNANTS OF TROPICAL ACTIVITY
   HAVE SHIFTED EAST OF THE RIO GRANDE AND ELONGATED SW-NE CORRIDOR OF
   CONVECTION WITH LIGHTNING SHOULD STEADILY ADVANCE EWD ACROSS THE
   COASTAL PLAINS OF TX INTO THE LOWER MS VALLEY OVER THE NEXT FEW
   HOURS.  HEAVY RAIN IS THE PRIMARY THREAT WITH THIS CONVECTION.

   ...OH VALLEY/LOWER GREAT LAKES...

   00Z SOUNDINGS FROM BUF AND PIT EXHIBIT WEAK BUOYANCY IN THE LOWEST
   FEW KM WITH SBCAPE ON THE ORDER OF 500 J/KG.  A NARROW BAND OF TSTMS
   HAS DEVELOPED ALONG LEADING EDGE OF BROADER CONVECTIVE BAND AND THIS
   ACTIVITY SHOULD ADVANCE INTO WRN NY/WRN PA BEFORE BOUNDARY LAYER
   COOLING PROVES DETRIMENTAL TO UPDRAFT STRENGTH.  LIGHTNING SHOULD
   WANE OVER THE NEXT FEW HOURS WITH LOSS OF DAYTIME HEATING.

   ...SERN AZ/SRN NM...

   ONSET OF DIURNAL COOLING WILL RESULT IN RAPIDLY WEAKENING TSTMS
   ACROSS SERN AZ/SRN NM OVER THE NEXT FEW HOURS.  UNTIL THEN SCT
   CONVECTION SHOULD DRIFT TOWARD THE MEXICAN BORDER WITH LITTLE MORE
   THAN A GUSTY WIND THREAT DUE TO RELATIVELY DRY SUB CLOUD LAYER.

   ..DARROW.. 09/21/2013

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z