SPC AC 221622

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1122 AM CDT MON SEP 22 2014

   VALID 221630Z - 231200Z

   ...NO SVR TSTM AREAS FORECAST...

   ...SUMMARY...
   THUNDERSTORMS MAY APPROACH OR BRIEFLY REACH SEVERE LEVELS TODAY OVER
   PARTS OF THE CENTRAL ROCKIES AND ADJACENT HIGH PLAINS...AS WELL AS
   THE GEORGIA AND SOUTH CAROLINA COASTAL PLAIN.

   ...SYNOPSIS...

   MORNING WATER VAPOR IMAGERY AND 12Z UPPER-AIR DATA INDICATE A
   SHORT-WAVE TROUGH OVER THE TN VALLEY WHICH WILL PROGRESS SEWD AND
   EVENTUALLY EVOLVE INTO A CLOSED MID-LEVEL CIRCULATION OVER THE
   CAROLINAS TOWARD 23/12Z. UPSTREAM FROM THESE DEVELOPMENTS...A
   SHORT-WAVE TROUGH OVER THE CNTRL ROCKIES WILL TRANSLATE ENEWD INTO
   THE NRN/CNTRL PLAINS...EFFECTIVELY UNDERCUTTING THE MEAN LONG-WAVE
   RIDGE IN PLACE WEST OF THE MS VALLEY.

   AT THE SURFACE...A COLD FRONT WILL CONTINUE SLOWLY SWD THROUGH THE
   SERN U.S...WITH THE POTENTIAL FOR WEAK FRONTAL WAVE DEVELOPMENT AS
   LARGE-SCALE FORCING FOR ASCENT IS ENHANCED BY THE SHORT-WAVE TROUGH
   MENTIONED ABOVE. ELSEWHERE...A LEE TROUGH WILL STRENGTHEN WHILE
   SHIFTING EWD THROUGH THE NRN AND CNTRL HIGH PLAINS.

   ...SERN STATES THIS AFTERNOON...

   A NE-SW-ORIENTED BAND OF SHOWERS AND TSTMS IS ONGOING AS OF MID
   MORNING ALONG OR IN THE IMMEDIATE WAKE OF THE COLD FRONT FROM CNTRL
   SC TO SERN AL. ABUNDANT SUNSHINE TO THE SOUTH OF THIS ACTIVITY ALONG
   WITH BOUNDARY-LAYER DEWPOINTS IN THE 60S WILL SUPPORT AIR MASS
   DESTABILIZATION WITH AFTERNOON MLCAPE APPROACHING 1000-1500 J/KG.
   THIS INSTABILITY IN CONJUNCTION WITH INCREASING HEIGHT FALLS/DCVA
   ASSOCIATED WITH THE MIGRATORY SHORT-WAVE TROUGH SHOULD PROMOTE AN
   UPTICK IN CONVECTIVE COVERAGE AND INTENSITY BY AFTERNOON AMIDST A
   KINEMATIC ENVIRONMENT FEATURING GRADUALLY STRENGTHENING VERTICAL
   SHEAR. AS SUCH...SOME POTENTIAL WILL EXIST FOR MULTICELLS OR LINE
   SEGMENTS CAPABLE OF LOCALLY DAMAGING WIND GUSTS AND/OR MARGINALLY
   SEVERE HAIL.

   ...CNTRL HIGH PLAINS THIS AFTERNOON/EVENING...

   THE MASS RESPONSE TO THE APPROACHING SHORT-WAVE TROUGH WILL MAINTAIN
   A 30-35 KT SLY LLJ ACROSS THE REGION TODAY...WHICH IN TURN WILL
   ENHANCE THE POLEWARD FLUX OF LOW-LEVEL MOISTURE E OF THE LEE TROUGH.
   CONSIDERABLE EARLY-DAY CLOUDINESS WILL SLOW THE DESTABILIZATION
   PROCESS...BUT WHERE CLOUD BREAKS CAN OCCUR...THE INCREASING MOISTURE
   MAY YIELD AFTERNOON MLCAPE APPROACHING 500-1000 J/KG. INCREASED
   FORCING FOR ASCENT ATTENDANT TO THE MID-LEVEL IMPULSE SHOULD BOLSTER
   TERRAIN-INDUCED CIRCULATIONS AND CONVERGENCE IN THE LEE OF THE FRONT
   RANGE TO FOSTER WIDELY SCATTERED TSTMS LATER TODAY. 

   MARGINAL SUPERCELL STRUCTURES ARE POSSIBLE OWING TO A VERTICALLY
   VEERING WIND PROFILE WITH DEEP-LAYER SHEAR STRENGTHENING TO 35-45
   KT. ISOLATED OCCURRENCES OF LARGE HAIL AND STRONG WIND GUSTS WILL BE
   THE PRIMARY HAZARDS...THOUGH A BRIEF TORNADO IS ALSO POSSIBLE.

   ..MEAD/LEITMAN.. 09/22/2014

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z