Jan 30, 2013 1630 UTC Day 1 Convective Outlook
Updated: Wed Jan 30 16:33:37 UTC 2013
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20130130 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20130130 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
20130130 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
20130130 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 301629
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1029 AM CST WED JAN 30 2013
   
   VALID 301630Z - 311200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THROUGH TONIGHT FOR THE SE
   STATES INTO THE MID ATLANTIC...
   
   ...SE STATES TO THE MID ATLANTIC THROUGH TONIGHT...
   AN INTENSE MIDLEVEL TROUGH WITH A BELT OF 100-130 KT MIDLEVEL FLOW
   WILL BEGIN TO ACCELERATE ENEWD FROM THE LOWER MS VALLEY LATER
   TODAY...AND WILL REACH THE MID ATLANTIC COAST EARLY THURSDAY.  AN
   ASSOCIATED SURFACE CYCLONE NOW LOCATED ACROSS NE IL/NW INDIANA WILL
   DEEPEN SUBSTANTIALLY WHILE TRANSLATING NEWD TOWARD SRN QUEBEC
   OVERNIGHT...AS A TRAILING SYNOPTIC COLD FRONT SURGES EWD ACROSS THE
   MS/OH VALLEYS AND APPALACHIANS.  HOWEVER...THE EFFECTIVE COLD FRONT
   IS DEMARCATED BY A PRE-FRONTAL SQUALL LINE THAT EXTENDS FROM WRN PA
   SWD ACROSS WV...ERN TN...NW GA...INTO CENTRAL AL AND SE MS AS OF
   16Z.  THIS PRE-FRONTAL BAND WILL LIKELY REMAIN THE PRIMARY FOCUS FOR
   CONVECTION THROUGH THE PERIOD...GIVEN THE EXTENSIVE TRAILING RAIN
   AREA THAT WILL REINFORCED THE COLD POOL THROUGH THE DAY.
   
   REGIONAL SURFACE OBSERVATIONS AND 12Z SOUNDINGS REVEAL THAT WARM
   SECTOR BUOYANCY IS LIMITED PRIMARILY TO AREAS FROM N GA SSWWD TO THE
   GULF COAST...WHERE BOUNDARY LAYER DEWPOINTS ARE IN THE MID-UPPER
   60S.  THIS IS THE SAME CORRIDOR WHERE OCCASIONAL STORMS HAVE BEEN
   MATURING IN THE WARM SECTOR AHEAD OF THE PRE-FRONTAL SQUALL
   LINE...IN AN ENVIRONMENT CHARACTERIZED BY MLCAPE OF 250-1000
   J/KG...EFFECTIVE BULK SHEAR OF 60-70 KT...AND EFFECTIVE SRH OF
   400-500 M2/S2.  THUS...THE RISK FOR TORNADOES /INCLUDING AN ISOLATED
   STRONG TORNADO/ WILL PERSIST INTO THE AFTERNOON ACROSS ERN AL INTO
   WRN GA WHERE VERTICAL SHEAR WILL REMAIN STRONG WITHIN THE MOIST
   AXIS.
   
   OTHERWISE...THE LOW-TOPPED QLCS EXTENDS WELL TO THE N INTO PA...AND
   THIS CONVECTIVE BAND WILL LIKELY PERSIST AND SPREAD E OF THE
   APPALACHIANS...EVENTUALLY REACHING THE MID ATLANTIC AND SE ATLANTIC
   COASTS BY EARLY THURSDAY MORNING.  SURFACE TEMPERATURES WARMING TO
   AOA 70 F AND BOUNDARY LAYER DEWPOINTS IN THE LOWER 60S WILL SUPPORT
   WEAK INSTABILITY E OF THE MOUNTAINS LATER THIS AFTERNOON /MAINLY
   FROM VA SWD/...THOUGH MLCAPE IS UNLIKELY TO EXCEED 100-250 J/KG
   GIVEN RATHER POOR LAPSE RATES ALOFT.  EVEN THOUGH LIGHTNING IS
   UNLIKELY FROM THE CAROLINAS NWD...THE WEAK BUOYANCY WILL BE
   SUFFICIENT TO MAINTAIN THE SHALLOW CONVECTIVE BAND AND AN ATTENDANT
   RISK OF DAMAGING WINDS...GIVEN 70-80 KT SSWLY FLOW IN THE LOWEST 1-2
   KM AGL.
   
   ..THOMPSON/COHEN.. 01/30/2013
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z