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Saturday, November 22, 2014

SEVERE WEATHER ALERT FOR SUNDAY: 11/23/2014

THE STORM PREDICTION CENTER IN NORMAN, OK HAS PLACED SIGNIFICANT AREAS OF THE EAST COAST AND SOUTHEAST / OHIO VALLEY / CENTRAL GULF COASTAL AREAS AND MS VALLEY AT SLIGHT -ENHANCED RISK OF SEVERE WEATHER FOR SUNDAY 11/23/2014



OFFICIAL NATIONAL WEATHER SERVICE FORECAST FOR THIS ALERT:


DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1258 AM CST SAT NOV 22 2014

   VALID 231200Z - 241200Z

   ...THERE IS AN ENH RISK OF SVR TSTMS FOR PORTIONS OF THE CENTRAL
   GULF COAST STATES...

   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE LOWER MS
   VALLEY EWD TO NRN FL AND THE CAROLINAS...

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PARTS OF ERN AR INTO THE
   LOWER OH VALLEY...

   ...SUMMARY...
   STRONG TO SEVERE THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE FROM THE
   LOWER MISSISSIPPI VALLEY EASTWARD ACROSS THE GULF COAST STATES AND
   NORTHEASTWARD INTO THE EASTERN CAROLINAS ON SUNDAY.  DAMAGING WIND
   GUSTS AND THE POSSIBILITY FOR A COUPLE OF TORNADOES ARE FORECAST TO
   BE THE PRIMARY THREATS.

   ...SYNOPSIS...
   A VIGOROUS LOWER-LATITUDE SHORTWAVE TROUGH OVER THE NWRN GULF COAST
   SUNDAY MORNING WILL RAPIDLY MOVE TO THE LOWER OH VALLEY BY EVENING. 
   CONCURRENTLY...AN INTENSIFYING MID-LEVEL SPEED MAX WILL STRENGTHEN
   TO 100 KT AS IT ROUNDS THE BASE OF A LARGER-SCALE TROUGH AND MOVES
   FROM THE SRN ROCKIES THROUGH THE LOWER MS VALLEY AND INTO KY/TN BY
   DAYBREAK MONDAY.

   IN THE LOW-LEVELS...A SURFACE LOW IS FORECAST TO DEVELOP/DEEPEN FROM
   OK TO THE MID MS RIVER VALLEY BY SUNDAY EVENING AND CNTRL GREAT
   LAKES EARLY MONDAY.  A WARM FRONT IS FORECAST TO ADVANCE NWD ACROSS
   THE LOWER MS AND TN RIVER VALLEYS DURING THE DAY AS A COLD FRONT
   MOVES EWD ACROSS THE MS VALLEY.

   ...LOWER MS VALLEY EWD INTO AL/GA/FL...
   SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS IN A CONVECTIVE LINE
   WILL LIKELY BE ONGOING AT DAYBREAK SUNDAY OVER THE LOWER MS VALLEY
   AND NWRN GULF OF MEXICO.  THE NWD ADVANCING WARM FRONT FOLLOWED BY
   MIDDLE 60S DEWPOINTS INTO CNTRL MS AND AL WILL LEAD TO MARGINAL
   BUOYANCY /250-1000 J PER KG MLCAPE/ IMMEDIATELY DOWNSTREAM OF THE
   SQUALL LINE.  STRONG MID-LEVEL HEIGHT FALLS COMBINED WITH A
   STRENGTHENING LLJ /50 KT/ AND STRONG DEEP-LAYER SHEAR WILL SUPPORT
   THE POSSIBILITY FOR A STRONGLY FORCED LINE MOVING ACROSS THE LOWER
   MS VALLEY INTO PORTIONS OF AL.  AN ENHANCED RISK FOR DMGG WIND AND
   AN ISOLD TORNADO MAY ACCOMPANY ANY LONGER-LIVED EMBEDDED
   MESOVORTICES/SUPERCELLS AND BOWING SEGMENTS AS THE LINE MOVES EWD
   ALONG THE CNTRL GULF COAST STATES.

   DURING THE MORNING AND FARTHER E...A NWD ADVANCING WARM FRONT OVER
   THE NERN GULF STATES WILL AID IN FOCUSING LIFT AS 60S DEG F BOUNDARY
   LAYER DEWPOINTS MOVE NWD INTO CNTRL PORTIONS OF GA/AL.  ALTHOUGH
   MUCH OF THIS ACTIVITY MAY BE ELEVATED NEAR THE FRONT...AN ISOLD
   STRONG TO SEVERE STORM THREAT MAY ACCOMPANY A FEW OF THESE STORMS IF
   PARCELS CAN ROOT NEAR THE SURFACE.  

   ...ERN CAROLINAS SUNDAY NIGHT...
   THE SYNOPTIC WARM FRONT IS FORECAST TO MOVE NWD THROUGH THE
   CAROLINAS DURING THE PERIOD AND SERVE TO CONCENTRATE
   SHOWERS/THUNDERSTORMS OVER THE CAROLINAS.  A STRONG POLEWARD
   MOISTURE FLUX WILL PROBABLY LEAD TO APPRECIABLE MOISTURE
   INFILTRATING THE COASTAL PLAIN AND PIEDMONT DOWNSTREAM OF THE
   INTENSE MID-LEVEL JET MOVING INTO KY/TN DURING THE OVERNIGHT. 
   DESPITE MODEST MID-LEVEL LAPSE RATES...THE COMBINATION OF INCREASING
   BUOYANCY AND STRENGTHENING SHEAR PROFILES WILL SUPPORT PERHAPS AN
   INCREASING RISK FOR DMGG WINDS AND A FEW TORNADOES.

   ...LOWER TN/OH VALLEYS...
   CONSIDERABLE UNCERTAINTY REMAINS REGARDING THE DEGREE OF
   DESTABILIZATION THAT CAN OCCUR FROM NERN AR NEWD INTO THE LOWER OH
   VALLEY WITH EXPECTED WIDESPREAD SHOWERS/THUNDERSTORMS FORECAST
   FARTHER S.  NONETHELESS...THE PRIMARY SURFACE CYCLONE IS PROGGED TO
   REACH THE MID MS VALLEY BY LATE AFTERNOON.  A WARM FRONT WILL LIFT
   NWD THROUGH THIS AREA FOLLOWED BY RELATIVELY MOIST UPPER 50S
   DEWPOINTS.  YET...COOLER MID-LEVEL TEMPS IN CLOSER PROXIMITY TO THE
   LARGER-SCALE TROUGH AND DOWNSTREAM OF THE AFOREMENTIONED MID-LEVEL
   JET MAY RESULT IN A FEW STRONGER STORMS PRIMARILY CAPABLE OF AN
   ISOLD DMGG WIND THREAT.