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 1965
< Previous MD         Next MD >
MD 1965 graphic

   MESOSCALE DISCUSSION 1965
   NWS STORM PREDICTION CENTER NORMAN OK
   0553 PM CST FRI DEC 05 2014

   AREAS AFFECTED...PORTIONS OF NERN PA...NWRN NJ...AND SERN NY

   CONCERNING...FREEZING RAIN 

   VALID 052353Z - 060400Z

   SUMMARY...AN AREA OF LIGHT TO MDT FZRA WILL CONTINUE TO SPREAD NE
   INTO THE EARLY OVERNIGHT HOURS...WITH ICE ACCRETION RATES OF A FEW
   HUNDREDTHS OF AN INCH PER HOUR.

   DISCUSSION...PER 23Z WATER VAPOR IMAGERY...A WEAK SHORTWAVE TROUGH
   EMBEDDED IN LARGER-SCALE WLY FLOW ALOFT WAS TRANSITING E ACROSS THE
   ERN GREAT LAKES. BROAD ADIABATIC ASCENT IN COMBINATION WITH WEAK
   CYCLONIC VORTICITY ADVECTION ALOFT IS PROMOTING A CONTINUATION AND
   NEWD EXPANSION OF A RELATIVELY LARGE PRECIP FIELD ACROSS THE REGION.
   IT SHOULD BE NOTED THAT RADAR REFLECTIVITY IS BEING ENHANCED BY
   BRIGHT-BANDING...AS EVIDENCED BY DUAL-POLARIZATION DATA FROM LOCAL
   WSR-88DS. FURTHERMORE...KBGM CORRELATION COEFFICIENT DATA INDICATE A
   POTENTIAL REFREEZING SIGNATURE/LOCAL MODIFICATION OF THE MELTING
   LAYER NEAR/NW OF KMSV...INDICATIVE OF ICE PELLETS WHICH WOULD
   LOCALLY REDUCE FZRA AMOUNTS. NONETHELESS...WHILE FZRA RATES ARE
   UNLIKELY TO BE PARTICULARLY HEAVY AS A RESULT OF THE AFOREMENTIONED
   WEAK FORCING...SFC OBS ACROSS THE HIGHLIGHTED AREA INDICATE
   EVAPORATIVE COOLING AND COLD-AIR DAMMING WILL LIKELY KEEP TEMPS AOB
   FREEZING OVER THE NEXT 3-4 HRS. AS SUCH...ICE ACCRETION RATES OF A
   FEW HUNDREDTHS OF AN INCH PER HOUR ARE POSSIBLE. BY LATE
   TONIGHT...WAA SHOULD ALLOW FOR TEMPS TO RISE ABOVE FREEZING...WITH A
   SUBSEQUENT REDUCTION OF THE FZRA THREAT.

   ..PICCA/THOMPSON.. 12/05/2014


   ATTN...WFO...OKX...ALY...PHI...BGM...

   LAT...LON   40957586 41467537 41597526 41827512 42547479 42547442
               42357429 41617418 41327435 41037470 40757570 40957586 

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 06, 2014
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities