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 1955
< Previous MD         Next MD >
MD 1955 graphic

   MESOSCALE DISCUSSION 1955
   NWS STORM PREDICTION CENTER NORMAN OK
   0728 AM CST WED NOV 26 2014

   AREAS AFFECTED...PARTS OF SWRN VA / ERN AND NERN WV / S-CNTRL PA

   CONCERNING...HEAVY SNOW 

   VALID 261328Z - 261730Z

   SUMMARY...SNOWFALL RATES AROUND 1 INCH PER HOUR ARE EXPECTED THIS
   MORNING.  THE HEAVIER SNOWFALL RATES WILL INITIAL BE CONFINED TO
   LOCALIZED AREAS BUT WILL BECOME MORE WIDESPREAD TOWARDS THE MID-LATE
   MORNING HOURS.

   DISCUSSION...13Z SURFACE MESOANALYSIS SHOWS THE 32 DEG F ISOTHERM
   INVOF THE VA/WV BORDER NEAR AND W OF THE SHENANDOAH VALLEY NEWD INTO
   WRN MD AND S-CNTRL PA.  OBSERVATIONAL TRENDS HAVE SHOWN THE AREA AOB
   FREEZING BECOMING MORE WIDESPREAD WITH TIME AS HEAVIER PRECIP RATES
   AND WET-BULB COOLING CONTRIBUTE TO COOLING PROCESSES NEAR THE
   SURFACE.  THE 12Z RNK RAOB SHOWED THE TEMP PROFILE NEAR OR BELOW 0
   DEG C FROM THE SURFACE UP THROUGH THE TROPOSPHERE...SUPPORTIVE OF
   SNOW P-TYPE.  FARTHER NE...THE 12Z IAD RAOB SHOWED A TEMP PROFILE
   ABOVE FREEZING IN THE SURFACE-1 KM LAYER.  

   MODELS INDICATE H7-H5 UPWARD VERTICAL MOTION TO MAXIMIZE OVER THE
   SRN HALF OF THE DISCUSSION AREA THROUGH 16Z WITH A SHIFT NWD NEAR
   AND NORTH OF THE MASON-DIXON LINE AFTER 16Z.  MODELS SHOW THE
   DENDRITIC GROWTH ZONE /-12 TO -17 DEG C/ TO OVERLAP WITH STRONG
   UPWARD VERTICAL MOTION AND THIS WILL LIKELY FAVOR HEAVIER PRECIP
   RATES.  A FURTHER EXPANSION IN AREA OF NEAR-SURFACE TEMPS AOB 32 DEG
   WILL FAVOR SNOW BECOMING MORE WIDESPREAD AND 1 INCH PER HOUR RATES
   WILL BECOME MORE COMMON THROUGH THE MID TO LATE MORNING HOURS.

   ..SMITH.. 11/26/2014


   ATTN...WFO...CTP...LWX...RNK...PBZ...RLX...

   LAT...LON   40337868 40647810 40717761 40437742 40047762 39307833
               38627904 37168024 37148068 37318084 39527941 40337868 

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: November 26, 2014
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities