Apr 16, 2011 1630 UTC Day 1 Convective Outlook
Updated: Sat Apr 16 16:54:44 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

The SPC is forecasting ...tornado outbreak expected over parts of cntrl/ern nc and far ern sc this afternoon into this evening....   Please read the latest public statement about this event.

Categorical Graphic
20110416 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20110416 1630 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20110416 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20110416 1630 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 161630
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1130 AM CDT SAT APR 16 2011
   
   VALID 161630Z - 171200Z
   
   ...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PARTS OF ERN NC AND FAR
   ERN SC...
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SC...NC AND
   VA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE
   MID-ATLANTIC...CAROLINAS AND ERN GA...
   
   ...TORNADO OUTBREAK EXPECTED THIS AFTERNOON AND EARLY THIS EVENING
   ACROSS ERN NC AND FAR ERN SC WHERE A HIGH RISK HAS BEEN ADDED...
   
   ...CAROLINAS/VA/WV/MID-ATLANTIC/ERN GA...
   A VIGOROUS UPPER-LEVEL TROUGH WILL MOVE INTO THE OH AND TN VALLEYS
   TODAY AS A WELL-DEFINED 70 TO 85 KT MID-LEVEL JET ROUNDS THE BASE OF
   THE TROUGH AND NOSES INTO THE CAROLINAS. THE JET WILL CREATE STRONG
   DEEP LAYER SHEAR PROFILES WHICH WILL BE VERY FAVORABLE FOR SEVERE
   STORMS AND TORNADOES THIS AFTERNOON. AT THE SFC A COLD FRONT WILL
   MOVE QUICKLY EWD ACROSS THE SRN APPALACHIAN MOUNTAINS. AHEAD OF THE
   FRONT...MODERATE DESTABILIZATION WILL LIKELY TAKE PLACE TODAY ALONG
   A MOIST AXIS WHERE SFC DEWPOINTS WILL BE IN THE MID TO UPPER 60S F.
   STRONG THUNDERSTORMS SHOULD INITIATE ON THE WRN EDGE OF THE MOIST
   AXIS IN THE WRN CAROLINAS AND RAPIDLY INCREASE IN COVERAGE EARLY
   THIS AFTERNOON. SEVERE STORMS ARE FORECAST TO MOVE INTO THE
   CNTRL/ERN CAROLINAS AND ACROSS CNTRL/ERN VA LATE THIS AFTERNOON INTO
   EARLY THIS EVENING.
   
   FORECAST SOUNDINGS ALONG THE MOIST AXIS IN THE ERN CAROLINAS AT 21Z
   SHOW 0-6 KM SHEAR VALUES AROUND 60 KT WITH MLCAPE OF 1500 TO 2000
   J/KG. IN ADDITION...LOW-LEVEL SHEAR WILL BE STRONG SUGGESTING THE
   THERMODYNAMIC AND SHEAR ENVIRONMENT WILL BE VERY FAVORABLE FOR
   SUPERCELLS AND TORNADOES IN THE MODERATE AND HIGH RISK AREAS. 0 TO 3
   KM STORM RELATIVE HELICITIES IN THE 450 TO 550 M2/S2 RANGE WILL ALSO
   BE FAVORABLE FOR STRONG TORNADOES WITH THE MORE DOMINANT DISCRETE
   SUPERCELLS. THE GREATEST THREAT FOR STRONG TORNADOES SHOULD EXIST
   FROM RALEIGH NC SSWWD TO NEAR FLORENCE SC AND EAST OF THAT LINE
   ABOUT 100 STATUTE MILES. THIS AREA WILL BE LOCATED WHERE THE
   CROSSOVER OF THE LOW AND MID-LEVEL JET IS MAXIMIZED. A LONG-TRACK
   TORNADO OR TWO IS EXPECTED TO OCCUR ACROSS THE HIGH RISK AREA IN ERN
   NC AND FAR ERN SC. AS STORM COVERAGE INCREASES THIS AFTERNOON AND A
   LINE OF STORMS ORGANIZES...A WIND DAMAGE THREAT WILL ALSO DEVELOP
   FROM THE MID-ATLANTIC SWD ACROSS THE CAROLINAS INTO ERN GA. 50 KT OF
   FLOW JUST ABOVE THE SFC AND A FAST EWD MOTION OF THE LINE SHOULD
   RESULT IN A WIDESPREAD WIND DAMAGE THREAT WITH VERY STRONG WIND
   GUSTS POSSIBLE WITH THE MORE INTENSE BOWING LINE-SEGMENTS ACROSS THE
   MODERATE AND HIGH RISK AREAS. SUPERCELLS AND THE MORE INTENSE CELLS
   WITHIN THE LINE SHOULD BE CAPABLE OF PRODUCING LARGE HAIL AS WELL.
   THE LINE IS FORECAST TO MOVE ACROSS THE OUTER BANKS OF NC THIS
   EVENING WITH THE SEVERE THREAT ENDING FROM WEST TO EAST ACROSS THE
   REGION.
   
   WHILE SHEAR CONDITIONS WILL BE FAVORABLE FOR TORNADOES AS FAR NORTH
   AS NRN VA AND MD...THE THREAT WILL BE MORE CONDITIONAL. ACROSS ERN
   GA...THIS AREA WILL BE SOUTH OF THE MID-LEVEL JET AND REMOVED FROM
   THE STRONG LARGE-SCALE ASCENT SUGGESTING THE SEVERE THREAT WILL
   REMAIN MORE ISOLATED ACROSS ERN GA.
   
   ..BROYLES/SMITH.. 04/16/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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