SPC AC 161720

   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1220 PM CDT WED OCT 16 2013

   VALID 171200Z - 181200Z

   ...NO SVR TSTM AREAS FORECAST...

   ...SYNOPSIS...
   DOWNSTREAM OF A BLOCKING UPPER RIDGE...WHICH HAS BECOME MORE
   PROMINENT ACROSS THE NORTHEAST PACIFIC...CYCLONIC MID/UPPER FLOW
   WILL PREVAIL FROM THE EASTERN GREAT BASIN AND ROCKIES EAST
   NORTHEASTWARD THROUGH THE MIDDLE AND NORTHERN ATLANTIC SEABOARD
   DURING THIS FORECAST PERIOD.  THIS LATTER REGIME WILL CONTAIN A
   NUMBER OF PROGRESSIVE SHORT WAVE IMPULSES...A COUPLE OF WHICH MAY
   ENHANCE LARGE-SCALE FORCING FOR UPWARD VERTICAL MOTION ALONG A
   FRONTAL ZONE SLOWLY ADVANCING EAST OF THE APPALACHIANS THROUGH THE
   ATLANTIC SEABOARD...AND NEAR ANOTHER DEVELOPING FRONTAL ZONE ACROSS
   THE SOUTH CENTRAL HIGH PLAINS

   AT THE SAME TIME...SUBTROPICAL RIDGING TO THE SOUTH APPEARS LIKELY
   TO WEAKEN SOME...BUT IS STILL EXPECTED TO MAINTAIN SUBSTANTIVE
   INFLUENCE ACROSS THE GULF OF MEXICO AND THE FLORIDA PENINSULA.  A
   PERTURBATION MIGRATING AROUND THE PERIPHERY OF THIS FEATURE COULD
   CONTRIBUTE TO ANOTHER AREA OF ENHANCED MID-LEVEL FORCING FOR ASCENT
   ALONG THE STALLED SOUTHWESTERN FLANK OF THE EAST COAST
   FRONT...ACROSS PARTS OF DEEP SOUTH TEXAS BY LATE THURSDAY OR
   THURSDAY NIGHT.

   AT LEAST LOW PROBABILITIES FOR THUNDERSTORM ACTIVITY APPEAR TO EXIST
   WITH THE AFOREMENTIONED SCATTERED AREAS OF ENHANCED FORCING FOR
   UPWARD VERTICAL MOTION.  HOWEVER...DESTABILIZATION IS EXPECTED TO BE
   QUITE WEAK...WITH GENERALLY NEGLIGIBLE SEVERE STORM POTENTIAL.

   ...APPALACHIANS/ATLANTIC SEABOARD...
   LOW THUNDERSTORM PROBABILITIES ACROSS PARTS OF CENTRAL ALABAMA INTO
   THE SOUTHERN APPALACHIANS APPEAR MOSTLY IN THE 17/12-18Z TIME
   FRAME...BEFORE MID-LEVEL FORCING FOR ASCENT WEAKENS/SHIFTS NORTHEAST
   OF THE REGION...ASSOCIATED WITH THE EAST NORTHEAST PROGRESSION OF A
   SIGNIFICANT SHORT WAVE TROUGH THROUGH THE OHIO VALLEY.  MODELS ARE
   SUGGESTIVE THAT THIS IMPULSE COULD AGAIN CONTRIBUTE TO MARGINALLY
   FAVORABLE PROFILES FOR THUNDERSTORM ACTIVITY TOWARD THE 17/21-18/03Z
   TIME FRAME...MAINLY NEAR AND NORTH/EAST OF THE ALLEGHENY MOUNTAINS.

   ...SOUTH CENTRAL HIGH PLAINS...
   IT APPEARS POSSIBLE THAT A WEAK RETURN FLOW OF MOISTURE TO A
   STRENGTHENING LOWER/MID TROPOSPHERIC WARM ADVECTION REGIME COULD
   CONTRIBUTE TO SUFFICIENT DESTABILIZATION FOR WEAK THUNDERSTORMS
   THURSDAY NIGHT...PARTICULARLY TOWARD THE 18/09-12Z TIME FRAME ACROSS
   PARTS OF SOUTHWESTERN KANSAS AND NORTHWESTERN OKLAHOMA.

   ...DEEP SOUTH TEXAS...
   THE BEST CHANCE FOR THUNDERSTORMS ACCOMPANYING THE SUBTROPICAL
   IMPULSE APPEARS TO EXIST ALONG IMMEDIATE COASTAL AREAS...AND IN THE
   OFFSHORE WATERS AFTER 18/06Z.

   ..KERR.. 10/16/2013

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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z