Jan 11, 2012 1630 UTC Day 1 Convective Outlook
Updated: Wed Jan 11 16:33:02 UTC 2012
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20120111 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20120111 1630 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Probabilistic Damaging Wind Graphic
20120111 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Probabilistic Large Hail Graphic
20120111 1630 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
   SPC AC 111629
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1029 AM CST WED JAN 11 2012
   
   VALID 111630Z - 121200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY
   TONIGHT FOR NE SC AND EXTREME ERN NC...
   
   ...NE SC/ERN NC THIS AFTERNOON THROUGH EARLY TONIGHT...
   THE MIDLEVEL SHORTWAVE TROUGH OVER AL THIS MORNING WILL EJECT NEWD
   TO THE MID ATLANTIC REGION BY TONIGHT AS AN UPSTREAM TROUGH
   AMPLIFIES OVER THE CENTRAL STATES.  AT THE SURFACE...A LOW NEAR THE
   AL/GA/TN BORDER WILL MOVE NNEWD IMMEDIATELY W OF THE
   APPALACHIANS...WHILE A SECONDARY LOW MAY FORM BY THIS EVENING/EARLY
   TONIGHT E OF THE BLUE RIDGE AS THE MIDLEVEL WAVE EJECTS NEWD...AND
   THE WARM FRONT SPREADS INLAND.
   
   RECENT SURFACE OBSERVATIONS SHOW THAT DEWPOINTS HAVE INCREASED INTO
   THE LOWER 60S AS THE WARM SECTOR BEGINS TO SPREAD INLAND ACROSS
   COASTAL SC.  THIS TREND WILL CONTINUE NEWD INTO ERN NC LATER TODAY
   INTO EARLY TONIGHT AS THE SYNOPTIC SYSTEM MOVES NEWD...RESULTING IN
   MODEST LOW-LEVEL DESTABILIZATION.  DESPITE RATHER POOR LAPSE RATES
   ALOFT AND WIDESPREAD CLOUDS...WEAK SURFACE-BASED INSTABILITY WILL BE
   POSSIBLE IN A NARROW ZONE NEAR THE COAST IN ADVANCE OF THE COLD
   FRONT...WHERE WIND PROFILES WILL BE FAVORABLE FOR EMBEDDED
   SUPERCELLS WITH AN ATTENDANT RISK FOR ISOLATED DAMAGING GUSTS AND A
   TORNADO OR TWO.  
   
   ...FL PENINSULA THIS AFTERNOON...
   A BROKEN BAND OF THUNDERSTORMS ALONG THE SURFACE COLD FRONT IS
   APPROACHING THE W CENTRAL FL COAST.  THE STORMS ARE CURRENTLY BEING
   MAINTAINED BY RICHER MOISTURE OVER THE E CENTRAL GULF OF
   MEXICO...WHEREAS A LITTLE DRIER AIR MASS RESIDES INLAND AND
   WIDESPREAD CLOUDS WILL SLOW SURFACE HEATING.  MEANWHILE...
   DEEP-LAYER VERTICAL SHEAR IS SUFFICIENT FOR EMBEDDED ROTATING
   STORMS...AND WILL REMAIN SO INTO EARLY AFTERNOON.  STILL...IT
   APPEARS THAT THE MARGINAL THERMODYNAMIC ENVIRONMENT WILL LIMIT THE
   INLAND RISK FOR DAMAGING WINDS AND A TORNADO THIS AFTERNOON...THUS
   WILL MAINTAIN LOW SEVERE PROBABILITIES.  
   
   ...N GA/ERN TN THIS AFTERNOON...
   WEAK INSTABILITY IS EXPECTED THIS AFTERNOON IN A NARROW CORRIDOR
   NEAR THE OCCLUDING SURFACE LOW...WHERE MID-UPPER 50S BOUNDARY LAYER
   DEWPOINTS AND SOME SURFACE HEATING PERSIST BENEATH A POCKET OF
   MIDLEVEL LAPSE RATES NEAR 7 C/KM.  A SMALL ARC OF CONVECTION IS
   EXPECTED TO CONTINUE IMMEDIATELY IN ADVANCE OF THE LOW...AND THERE
   WILL BE A SMALL WINDOW OF OPPORTUNITY FOR STORMS TO PRODUCE
   MARGINALLY SEVERE HAIL AND GUSTY WINDS.
   
   ..THOMPSON/COHEN.. 01/11/2012
   
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