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 34
< Previous MD         Next MD >
MD 34 graphic

   MESOSCALE DISCUSSION 0034
   NWS STORM PREDICTION CENTER NORMAN OK
   0518 PM CST SAT JAN 17 2015

   AREAS AFFECTED...PORTIONS OF N-CNTRL WA

   CONCERNING...WINTER MIXED PRECIPITATION 

   VALID 172318Z - 180315Z

   SUMMARY...LIGHT TO MODERATE FREEZING RAIN...OCCASIONALLY MIXED WITH
   BRIEF SLEET/SNOW...WILL DEVELOP THROUGH THIS EVENING. ICE ACCRETION
   RATES OF A FEW HUNDREDTHS OF AN INCH PER HOUR WILL BE POSSIBLE.

   DISCUSSION...PER REGIONAL WSR-88D MOSAIC AS OF 23Z..A LARGE SHIELD
   OF PCPN CONTINUES TO SPREAD EAST ACROSS PORTIONS OF THE PACIFIC
   NORTHWEST. LATEST OBSERVATIONS AND GUIDANCE INDICATE THIS AREA OF
   PCPN WILL CONTINUE THROUGH EARLY TONIGHT AS INCREASING DCVA AHEAD OF
   AN APPROACHING SHORTWAVE TROUGH WORKS IN CONCERT WITH STRENGTHENING
   ADIABATIC ASCENT AND FRONTOGENETIC CIRCULATIONS ALOFT. 

   ALONG PORTIONS OF THE EASTERN SLOPES OF THE CASCADE
   RANGE...SUB-FREEZING AIR CONTINUES TO BE IN PLACE PER 22Z
   OBSERVATIONS...WITH SEVERAL SITES AROUND 28-31 DEG F.
   ADDITIONALLY...WHILE RADAR COVERAGE ACROSS THIS AREA IS
   LACKING...LATEST KATX DUAL-POL DATA EXHIBIT A CLEAR MELTING LAYER
   SIGNATURE EXTENDING TO APPROXIMATELY 8-9 THOUSAND FT ABOVE RADAR
   HEIGHT. WHILE PERIODS OF SNOW AND SLEET ARE POSSIBLE LATE THIS
   AFTERNOON AND EVENING...FORECAST SOUNDINGS INDICATE AS THIS WARMER
   LAYER ALOFT SLOWLY PROGRESSES EAST OF THE CASCADE
   RANGE...SUB-FREEZING AIR NEAR THE SFC WILL REMAIN IN PLACE. AS
   SUCH...THERMAL PROFILES WILL LIKELY SUPPORT FZRA THIS EVENING...WITH
   ICE ACCRETION RATES OF SEVERAL HUNDREDTHS OF AN INCH PER HOUR
   POSSIBLE.

   ..PICCA/EDWARDS.. 01/17/2015


   ATTN...WFO...OTX...PDT...SEW...

   LAT...LON   47382112 47882097 48552075 48712054 48702015 48601978
               47991964 47152027 47132059 47152078 47052102 47192117
               47382112 

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: January 18, 2015
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities