Sep 28, 2016 1730 UTC Day 2 Convective Outlook
Updated: Wed Sep 28 17:11:23 UTC 2016 (20160928 1730Z Day 2 shapefile | 20160928 1730Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20160928 1730 UTC Day 2 Outlook Graphic
Day 2 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 85,671 13,649,735 Charlotte, NC...Raleigh, NC...Pittsburgh, PA...Greensboro, NC...Durham, NC...
Probabilistic Graphic
20160928 1730 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Day 2 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 85,369 13,682,783 Charlotte, NC...Raleigh, NC...Pittsburgh, PA...Greensboro, NC...Durham, NC...
   SPC AC 281711

   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1211 PM CDT WED SEP 28 2016

   VALID 291200Z - 301200Z

   ...THERE IS A MRGL RISK OF SVR TSTMS THURSDAY ACROSS THE PIEDMONT OF
   CAROLINAS AND VIRGINIA...AND THE CENTRAL APPALACHIANS INTO THE UPPER
   OHIO VALLEY...

   ...SUMMARY...
   THUNDERSTORMS ARE EXPECTED ACROSS THE PIEDMONT OF THE CAROLINAS AND
   VIRGINIA...AND THE CENTRAL APPALACHIANS INTO THE UPPER OHIO
   VALLEY...ON THURSDAY...ACCOMPANIED BY AT LEAST SOME RISK FOR SEVERE
   HAIL AND LOCALLY STRONG SURFACE GUSTS.

   ...SYNOPSIS...
   A DEEP CLOSED LOW NOW DIGGING INTO THE OHIO VALLEY...TO THE WEST OF
   THE CENTRAL APPALACHIANS...HAS BECOME INCREASINGLY CUT OFF FROM THE
   STRONGER MID-LATITUDE WESTERLIES.  LITTLE CHANGE APPEARS LIKELY
   THROUGH THIS FORECAST PERIOD.  A CONTINUED GRADUAL FILLING OF THE
   LOW IS POSSIBLE...BUT LITTLE NET EASTWARD PROGRESSION IS EXPECTED. 
   ANY MOVEMENT LIKELY WILL BE SUBTLE...AND GENERALLY IN RESPONSE TO
   SHORT WAVE PERTURBATIONS PIVOTING AROUND THE MID-LEVEL CIRCULATION
   CENTER.  TO ITS NORTHWEST AND NORTH...BROAD UPPER RIDGING WITHIN THE
   PRIMARY BELT OF WESTERLIES IS EXPECTED TO CONTINUE TO BUILD ACROSS
   PARTS OF THE NORTHERN ROCKIES AND CANADIAN PRAIRIES...WHILE
   EXPANDING EASTWARD ACROSS ONTARIO AND QUEBEC...DOWNSTREAM OF
   AMPLIFIED TROUGHING NEAR/WEST  OF THE PACIFIC COAST.  

   IN RESPONSE TO THESE DEVELOPMENTS...SOME CONTINUED SOUTHWARD
   PROGRESSION OF A SURFACE COLD FRONT ACROSS THE GULF COAST REGION IS
   POSSIBLE.  ADVANCEMENT ACROSS THE SOUTHERN APPALACHIANS AND SOUTH
   ATLANTIC COAST REGION MAY OCCUR BY THE END OF THE PERIOD...BUT
   MODELS INDICATE THAT THE FRONTAL ZONE WILL REMAIN STALLED SOUTH OF
   NEW ENGLAND COASTAL AREAS INTO THE MID ATLANTIC COAST REGION. 
   HIGHER MOISTURE CONTENT AIR WILL BE CONFINED TO AREAS
   ALONG/SOUTHEAST OF THE FRONT...BUT SUBSTANTIVE MOISTURE  WILL
   CONTINUE TO WRAP AROUND THE NORTHEASTERN AND NORTHERN PERIPHERY OF
   THE  LOW...ACROSS PARTS OF THE CENTRAL APPALACHIANS/OHIO VALLEY AND
   GREAT LAKES REGION.  AT THE SAME TIME...AT  LEAST MODEST MOISTENING
   MAY CONTINUE ON SOUTHERLY MEAN FLOW ACROSS PARTS OF THE
   INTERMOUNTAIN WEST AND ROCKIES.

   ...MID ATLANTIC/CENTRAL APPALACHIANS/UPPER OHIO VALLEY...
   THE MID-LEVEL COLD CORE OF THE CUT-OFF LOW APPEARS LIKELY TO REMAIN
   LARGELY WEST OF THE CREST OF THE CENTRAL APPALACHIANS THROUGH THIS
   PERIOD.  HOWEVER...ON ITS EASTERN PERIPHERY /ACROSS THE PIEDMONT OF
   THE CAROLINAS AND VIRGINIA...NORTHWARD ACROSS THE APPALACHIANS INTO
   THE UPPER OHIO VALLEY/ BREAKS IN CLOUD COVER BENEATH THE MID-LEVEL
   DRY SLOT PROBABLY WILL ALLOW FOR SUFFICIENT INSOLATION TO CONTRIBUTE
   TO WEAK TO MODEST BOUNDARY LAYER DESTABILIZATION BY THURSDAY
   AFTERNOON.  BENEATH RELATIVELY STRONG SOUTHERLY MID TO UPPER LEVEL
   FLOW /INCLUDING 40-50 KT AROUND 500 MB/...THE ENVIRONMENT PROBABLY
   WILL BECOME AT LEAST MARGINALLY CONDUCIVE TO ORGANIZED SEVERE STORM
   DEVELOPMENT...PERHAPS INCLUDING SUPERCELLS.  LOW-LEVEL HODOGRAPHS IN
   THE AREAS WITH THE MOST APPRECIABLE BOUNDARY LAYER DESTABILIZATION
   MAY REMAIN RATHER MODEST IN SIZE...AND TEND TO LIMIT TORNADIC
   POTENTIAL...BUT SEVERE HAIL AND LOCALLY STRONG SURFACE GUSTS WILL BE
   POSSIBLE IN STRONGEST STORMS.  AT THIS POINT...DUE TO SOME LINGERING
   UNCERTAINTIES...SLIGHT RISK PROBABILITIES WILL NOT BE
   INTRODUCED...BUT PROBABILITIES MAY NEED TO BE UPGRADED IN LATER
   OUTLOOKS FOR THIS TIME PERIOD.

   ..KERR.. 09/28/2016

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z