Skip Navigation Links weather.gov 
NOAA logo-Select to go to the NOAA homepage NOAA's National Weather Service   Select to go to the NWS homepage
Storm Prediction Center
navigation bar left  
  navigation bar end cap


 
USA.gov is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.

Mesoscale Discussion 1662
< Previous MD         Next MD >
MD 1662 graphic

   MESOSCALE DISCUSSION 1662
   NWS STORM PREDICTION CENTER NORMAN OK
   1230 PM CDT TUE AUG 11 2015

   AREAS AFFECTED...PORTIONS NRN GA...NWRN SC...W-CENTRAL NC...SRN
   THROUGH CENTRAL/NRN VA...CENTRAL/NRN MD...DC...SERN PA.

   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

   VALID 111730Z - 112000Z

   PROBABILITY OF WATCH ISSUANCE...5 PERCENT

   SUMMARY...WIDELY SCATTERED MULTICELLULAR TSTMS IN BOTH CLUSTERED AND
   DISCRETE MODES ARE EXPECTED TO MOVE ACROSS THIS REGION THROUGH
   MID-LATE AFTN...GRADUALLY INCREASING IN COVERAGE AND INTENSITY FOR
   ANOTHER 2-3 HOURS.  THREAT MOSTLY WILL BE FROM POTENTIALLY DAMAGING
   GUSTS APCHG SVR LIMITS...CAPABLE OF TREES DOWN AND BROKEN BRANCHES. 
   AN ISOLATED SEVERE/50-KT GUST CANNOT BE RULED OUT.

   DISCUSSION...SFC ANALYSIS SHOWS COLD FRONT FROM NERN PA SWWD ACROSS
   WV TO MID TN.  LOOSELY ORGANIZED SFC TROUGH WAS EVIDENT AHEAD OF
   FRONT FROM ERN PA AND NRN VA TO WRN PORTIONS NC AND NRN GA.  WEAK
   TROUGH/WIND-SHIFT WAS APPARENT FARTHER E FROM SRN VA TO CENTRAL GA. 
   BULK OF CONVECTION SHOULD BE CONCENTRATED NEAR THESE PREFRONTAL
   TROUGHS...WITH ACTIVITY ALSO POSSIBLE ALONG FRONT AND
   DIFFERENTIAL-HEATING ZONES.  

   VIS IMAGERY SHOWS INCREASING DEPTH OF CONVECTION WHERE HIGHER
   TERRAIN HAS EXPERIENCED A COUPLE HOURS OF FAVORABLE HEATING FROM NRN
   VA TO NRN GA...INCLUDING EARLY-STAGE/NON-SVR TSTMS.  CORRIDOR OF
   SUSTAINED...RELATIVELY CLOUD-FREE CONDITIONS IS APPARENT TO ITS
   E...UP AND DOWN PIEDMONT...WHERE WEAK MLCINH ALREADY IS APPARENT
   WITH FAVORABLE LOW-LEVEL MOISTURE.  GRADUAL INCREASE IN CONVECTIVE
   COVERAGE/INTENSITY SHOULD CONTINUE INTO MID/LATE AFTN.  MODIFIED
   REGIONAL RAOBS AND FCST SOUNDINGS SHOW VERY WEAK LAPSE RATES ABOVE
   BOUNDARY LAYER...SUCH THAT EVEN WITH SFC DEW POINTS COMMONLY 70S F
   AND STG SFC HEATING...MLCAPE SHOULD STAY BELOW 2000 J/KG RANGE IN
   MOST AREAS.  ORGANIZED SVR POTENTIAL WILL BE TEMPERED BY LACK OF
   MORE ROBUST LAPSE RATES/BUOYANCY...AND BY LACK OF DEEP SHEAR -- E.G.
   EFFECTIVE-SHEAR MAGNITUDES ONLY IN 25-30 KT RANGE ACROSS MOST OF
   THIS CORRIDOR DUE IN PART TO WLY COMPONENT OF NEAR-SFC WINDS. 
   LOCALIZED ENHANCEMENT TO TSTM-WIND POTENTIAL MAY ARISE WHERE
   AGGREGATION OF PROXIMAL STORM-SCALE COLD POOLS OCCURS AND DRIVES
   DEVELOPMENT OF SMALL BOWS.

   ..EDWARDS/HART.. 08/11/2015


   ATTN...WFO...PHI...AKQ...CTP...LWX...RAH...RNK...CAE...GSP...
   FFC...

   LAT...LON   34188514 34988286 37827886 38957819 40097634 39977555
               38647650 37867695 37457757 36017945 34328108 32798454
               34188514 

Top/All Mesoscale Discussions/Forecast Products/Home
Weather Topics:
Watches, Mesoscale Discussions, Outlooks, Fire Weather, All Products, Contact Us

NOAA / National Weather Service
National Centers for Environmental Prediction
Storm Prediction Center
120 David L. Boren Blvd.
Norman, OK 73072 U.S.A.
spc.feedback@noaa.gov
Page last modified: August 11, 2015
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities