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 1971
< Previous MD         Next MD >
MD 1971 graphic

   MESOSCALE DISCUSSION 1971
   NWS STORM PREDICTION CENTER NORMAN OK
   0844 PM CST TUE DEC 09 2014

   AREAS AFFECTED...NORTHERN MAINE

   CONCERNING...WINTER MIXED PRECIPITATION 

   VALID 100244Z - 100545Z

   SUMMARY...A 2-4 HOUR PERIOD OF HEAVY SNOW RATES UP TO 1+ INCHES PER
   HOUR POSSIBLE...BEFORE PRECIPITATION DIMINISHES IN INTENSITY AND
   CHANGES OVER TO SLEET AND EVENTUALLY FREEZING DRIZZLE OVER MOST
   AREAS AFTER 06-07Z.

   DISCUSSION...HEAVY SNOW...AT RATES UP TO 1+ INCHES PER
   HOUR...APPEARS IN THE PROCESS OF DEVELOPING/SPREADING NORTHWARD
   ACROSS MUCH OF NORTHERN MAINE...IN RESPONSE TO THE APPROACH OF AN
   INCREASINGLY DEFORMED/SHEARED MID-LEVEL IMPULSE.  THE LATEST MODEL
   AND OBSERVATIONAL DATA SUGGEST THAT THIS COULD PERSIST FOR A 2 TO 4
   HOUR PERIOD LATE THIS EVENING...BEFORE THE STRONGER MID/UPPER
   FORCING FOR UPWARD VERTICAL MOTION SHIFTS TO THE NORTH/NORTHEAST OF
   THE INTERNATIONAL BORDER.

   AROUND OR SHORTLY AFTER 06Z...WEAKENING ASCENT/INCREASING SUBSIDENCE
   AND DRYING WITHIN THE FAVORABLE DENDRITIC GROWTH LAYER 
   IS EXPECTED TO RESULT IN DIMINISHING SNOW RATES.  LOWER/MID
   TROPOSPHERIC WARM ADVECTION IS FORECAST TO PERSIST THROUGH THE
   NIGHT...HOWEVER...TO THE NORTHEAST OF THE QUASI-STATIONARY/SLOW
   MOVING SURFACE LOW OVER EASTERN MASSACHUSETTS.  IN ADDITION TO
   MAINTAINING LIGHT PRECIPITATION...PRONOUNCED WARMING ABOVE A
   RESIDUAL SUB-FREEZING SURFACE-BASED LAYER PROBABLY WILL CONTRIBUTE
   TO A CHANGEOVER TO SLEET AND FREEZING DRIZZLE...THOUGH 
   PRECIPITATION MAY REMAIN IN THE FORM OF LIGHT SNOW ACROSS FAR
   NORTHERN AROOSTOOK COUNTY.

   ..KERR.. 12/10/2014


   ATTN...WFO...CAR...GYX...

   LAT...LON   45337154 46287056 47206946 47346755 45806757 45376954
               45067068 45337154 

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: December 10, 2014
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities