Sep 26, 2016 1300 UTC Day 1 Convective Outlook
Updated: Mon Sep 26 12:40:22 UTC 2016 (20160926 1300Z Day 1 shapefile | 20160926 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20160926 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 37,490 4,812,152 Pittsburgh, PA...Charleston, WV...Huntington, WV...Blacksburg, VA...Mount Lebanon, PA...
Probabilistic Tornado Graphic
20160926 1300 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
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
20160926 1300 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 % 37,757 4,822,953 Pittsburgh, PA...Charleston, WV...Huntington, WV...Mount Lebanon, PA...Bethel Park, PA...
Probabilistic Large Hail Graphic
20160926 1300 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
No Risk Areas Forecast
   SPC AC 261240

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0740 AM CDT MON SEP 26 2016

   VALID 261300Z - 271200Z

   ...THERE IS A MRGL RISK OF SVR TSTMS PORTIONS UPPER OH VALLEY AND
   NEARBY APPALACHIANS...

   ...SUMMARY...
   A FEW STRONG TO SEVERE THUNDERSTORMS MAY OCCUR THIS AFTERNOON ACROSS
   PARTS OF THE UPPER OHIO RIVER VALLEY AND IN THE NEARBY APPALACHIANS.

   ...SYNOPSIS...
   UPPER-AIR SCHEME THROUGH PERIOD WILL BE CHARACTERIZED BY REX PATTERN
   OVER WRN CONUS/NWRN MEX...AND HEIGHT FALLS OVER MUCH OF ERN CONUS
   AHEAD OF ENLARGING/INTENSIFYING GREAT LAKES CYCLONE.  ASSOCIATED
   UPPER-LEVEL LOW -- NOW EVIDENT IN MOISTURE-CHANNEL IMAGERY OVER NWRN
   ONT JUST N OF MN BORDER -- IS FCST TO WOBBLE ERRATICALLY ESEWD
   TOWARD NRN LS THROUGH PERIOD...NEARLY STACKED WITH SFC CYCLONE. 
   MEANWHILE ASSOCIATED CYCLONIC-FLOW FIELD EXPANDS TO COVER AREAS FROM
   NRN PLAINS TO WRN NEW ENGLAND AND SRN APPALACHIANS NWD.  

   AS THAT OCCURS...ASSOCIATED SFC COLD FRONT -- ANALYZED AT 11Z FROM
   OCCLUSION TRIPLE POINT OVER WRN OH SWD ACROSS WRN TN...NWRN LA AND
   MIDDLE/LOWER TX COASTAL PLAIN -- WILL MOVE EWD/SEWD THROUGH PERIOD. 
   BY 00Z FRONT SHOULD BE LOCATED OVER WRN NY...WRN/CENTRAL PA...SRN
   WV...ERN TN...SRN MS...AND SRN LA.  BY 12Z FRONT SHOULD REACH NEW
   ENGLAND...DELMARVA...NRN GA...FL PANHANDLE...N-CENTRAL GULF.  WARM
   FRONT INITIALLY OVER ERN PORTIONS KY/TN AND WRN NC SHOULD MOVE
   IRREGULARLY ENEWD...AS TRIPLE POINT MIGRATES ERRATICALLY ACROSS NRN
   WV OR SWRN PA...THEN ROUGHLY OVER LOWER POTOMAC RIVER AREA THROUGH
   PERIOD. 

   ...UPPER OH VALLEY AND NEARBY APPALACHIANS...
   SCATTERED TSTMS ARE EXPECTED TO DEVELOP THIS AFTN IN NE-SW BAND...
   ROUGHLY PARALLEL TO AND ALONG OR SLIGHTLY AHEAD OF SFC COLD FRONT. 
   THIS MAY BE EITHER TEMPORAL TRANSLATION OF ONGOING ACTIVITY OVER
   OH/SERN INDIANA/WRN KY...OR ADDITIONAL DEVELOPMENT WITHIN SAME
   GENERAL PLUME OF LARGE-SCALE ASCENT AND FRONTAL FORCING.  THOUGH
   AVBL INSTABILITY WILL BE LIMITED...A FEW CELLS WITHIN THIS BAND MAY
   PRODUCE DAMAGING GUSTS NEAR SVR LIMITS.  

   NARROW/FOREGOING WARM SECTOR IS EXPECTED TO BE CHARACTERIZED BY SFC
   DEW POINTS 60S F...AND SUFFICIENT SFC DIABATIC HEATING TO OFFSET
   WEAK MID/UPPER-LEVEL LAPSE RATES AND YIELD SFC-BASED EFFECTIVE-
   INFLOW PARCELS.  MLCAPE 300-800 J/KG IS ANTICIPATED...AMIDST
   ESSENTIALLY UNIDIRECTIONAL LOW/MIDDLE-LEVEL WIND PROFILES SW OF WARM
   FRONT.  INSTABILITY GRADUALLY WILL BECOME NEUTRAL TO NEGATIVE FOR
   SFC PARCELS POLEWARD OF TRIPLE POINT.  DEEP SHEAR WILL BE INCREASING
   WITH TIME...AS UPPER CYCLONE APCHS...THOUGH STRONGEST VALUES SHOULD
   REMAIN BEHIND SFC COLD FRONT.  FCST SOUNDINGS SHOW EFFECTIVE-SHEAR
   MAGNITUDES STRUGGLING TO REACH 30 KT...AND OVERALL ORGANIZATION OF
   ACTIVITY SHOULD BE LIMITED AND GENERALLY MULTICELLULAR IN CHARACTER.

   ..EDWARDS/PICCA.. 09/26/2016

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z