Sep 30, 2016 2000 UTC Day 1 Convective Outlook
Updated: Fri Sep 30 19:34:00 UTC 2016 (20160930 2000Z Day 1 shapefile | 20160930 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20160930 2000 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 68,282 12,174,281 Columbus, OH...Virginia Beach, VA...Raleigh, NC...Norfolk, VA...Chesapeake, VA...
Probabilistic Tornado Graphic
20160930 2000 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.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
2 % 35,349 6,311,534 Columbus, OH...Norfolk, VA...Chesapeake, VA...Richmond, VA...Newport News, VA...
Probabilistic Damaging Wind Graphic
20160930 2000 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.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 68,160 12,149,455 Columbus, OH...Raleigh, NC...Norfolk, VA...Chesapeake, VA...Durham, NC...
Probabilistic Large Hail Graphic
20160930 2000 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.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 42,457 8,360,448 Columbus, OH...Raleigh, NC...Durham, NC...Richmond, VA...Newport News, VA...
   SPC AC 301934

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0234 PM CDT FRI SEP 30 2016

   VALID 302000Z - 011200Z

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PORTIONS OF ERN
   INDIANA/OH/WRN WV...

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PARTS OF SRN VA AND INTO
   NC/EXTREME NERN SC...

   ...SUMMARY...
   A FEW STRONG TO LOCALLY SEVERE THUNDERSTORMS REMAIN POSSIBLE TODAY
   ACROSS PORTIONS OF VIRGINIA AND NORTH CAROLINA AS WELL AS THE OHIO
   RIVER VALLEY.

   ...DISCUSSION...
   NO SUBSTANTIVE CHANGES ARE BEING MADE TO THE OUTLOOK ATTM...WITH
   ONLY MINOR LINE ADJUSTMENTS APPEARING NECESSARY.  RISK FOR A SEVERE
   STORM OR TWO WILL LINGER INTO EARLY EVENING ACROSS PORTIONS OF
   WV/OH/INDIANA...AS WELL AS PORTIONS OF THE VA AND NC VICINITY.

   ..GOSS.. 09/30/2016

   .PREV DISCUSSION... /ISSUED 1129 AM CDT FRI SEP 30 2016/

   ...NC THROUGH VA...

   AS OF MID DAY A QUASI-STATIONARY FRONT /PORTIONS OF WHICH HAVE BEEN
   CONVECTIVELY REINFORCED/ EXTENDS FROM NERN NC WSWWD TO A WEAK LOW
   PRESSURE AREA IN WRN NC. A COLD FRONT EXTENDS FROM ERN SC NWWD INTO
   CNTRL NC WHERE IT INTERSECTS THE STATIONARY FRONT. WIDESPREAD CLOUDS
   AND SCATTERED ONGOING STORMS CONTINUE THROUGH MUCH OF WARM
   SECTOR...BUT CLOUD BREAKS IN WAKE OF EARLY STORMS WILL RESULT IN AT
   LEAST MODEST BOUNDARY LAYER DESTABILIZATION...ESPECIALLY FROM NRN NC
   INTO A PORTION OF SRN VA. WEAK MID-LEVEL LAPSE RATES SHOULD LIMIT
   MLCAPE TO AOB 1500 J/KG WITH THE STRONGER INSTABILITY OVER ERN NC.
   STORMS DEVELOPING WITHIN AN ARC FROM ERN NC NWWD THROUGH WCNTRL VA
   WILL CONTINUE NWD INTO THE AFTERNOON. STRONGEST STORM WITH SUPERCELL
   STRUCTURES REMAINS OVER NCNTRL NC AND MAY CONTINUE TO POSE A
   SHORT-TERM THREAT FOR MAINLY HAIL AND STRONG WIND GUSTS...BUT A
   BRIEF TORNADO CANNOT BE RULED OUT. 

   IN WAKE OF ONGOING ARC OF STORMS...ADDITIONAL CONVECTION MAY DEVELOP
   WHERE THE SFC-LAYER IS DESTABILIZING IN VICINITY OF A NW-SE ORIENTED
   OUTFLOW BOUNDARY ACROSS NWRN THROUGH CNTRL NC AND NWD INTO SCNTRL
   VA. HOWEVER...WV IMAGERY SHOWS A ZONE OF SIGNIFICANT DRYING ALOFT
   SPREADING NWD...AND THIS WAS SAMPLED BY THE 12Z GSO RAOB. WEAK
   MID-LEVEL LAPSE RATES AND SUBSTANTIAL DRY AIR ALOFT MAY TEND TO
   REDUCE UPDRAFT STRENGTH THROUGH ENTRAINMENT...LIMITING OVERALL
   SEVERE POTENTIAL. NEVERTHELESS...A CONDITIONAL RISK FOR FEW STRONG
   TO SEVERE STORMS WILL REMAIN POSSIBLE INTO THE AFTERNOON GIVEN 40+
   KT EFFECTIVE SHEAR AND VEERING LOW-LEVEL WIND PROFILES SUPPORTIVE OF
   UPDRAFT ROTATION.  

   ...OH VALLEY AREA...

   THUNDERSTORMS CONTINUE DEVELOPING IN AN ARC WITHIN UPPER LOW
   CIRCULATION ACROSS CNTRL OH. DIABATIC WARMING OF THE BOUNDARY LAYER
   WITHIN ZONE OF CLEARING IN VICINITY OF THE STORMS MAY RESULT IN SOME
   INTENSIFICATION DURING THE AFTERNOON. COOL TEMPERATURES ALOFT AND
   DIABATIC WARMING WILL CONTRIBUTE TO WEAK BUOYANCY WHERE EFFECTIVE
   SHEAR IS SUPPORTIVE OF A FEW STORMS TO DEVELOP UPDRAFT ROTATION
   WHICH MAY PROMOTE A THREAT FOR SMALL TO MARGINALLY SEVERE HAIL AND
   PERHAPS A BRIEF TORNADO.

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z