Skip Navigation Links weather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center

 
 

 

Follow the Weather Prediction Center on Facebook Follow the Weather Prediction Center on Twitter
NCEP Quarterly Newsletter
WPC Home
Analyses and Forecasts
   National High & Low
   WPC Discussions
   Surface Analysis
   Days ½-2½ CONUS
   Days 3-7 CONUS
   Days 4-8 Alaska
   QPF
   PQPF
   Flood Outlook
   Winter Weather
   Storm Summaries
   Heat Index
   Tropical Products
   Daily Weather Map
   GIS Products
Current Watches/
Warnings

Satellite and Radar Imagery
  GOES-East Satellite
  GOES-West Satellite
  National Radar
Product Archive
WPC Verification
   QPF
   Medium Range
   Model Diagnostics
   Event Reviews
   Winter Weather
International Desks
Development and Training
   Development
WPC Overview
   About the WPC
   Staff
   WPC History
   Accomplishments
   Other Sites
   FAQs
Meteorological Calculators
Contact Us
   About Our Site
 
USA.gov is the U.S. Government's official web portal to all federal, state, and local government web resources and services.
 
Winter Weather Forecast Discussion
 
(Caution: Version displayed is not the latest version. - Issued 0825Z Feb 25, 2018)
 
Version Selection
Versions back from latest:  0   1   2   3   4   5   6   7   8   9   10   
 
Abbreviations and acronyms used in this product
 
Geographic Boundaries -  Map 1: Color  Black/White       Map 2: Color  Black/White


PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
325 AM EST SUN FEB 25 2018

VALID 12Z SUN FEB 25 2018 - 12Z WED FEB 28 2018


...WEST...

A RATHER ACTIVE UPPER-LEVEL JET AND SHORT WAVE TROUGH OVER THE
NERN PAC AND ALONG THE BRITISH COLUMBIA COAST WILL DIG DOWN THE
ENTIRE WEST COAST OVER THE NEXT THREE DAYS TO PRODUCE HEAVY SNOW
FROM THE PAC NW TO THE TERRAIN IN THE DESERT SW. A VERY ACTIVE AND
UNSETTLED SUN ACROSS THE ENTIRE NWRN QUAD OF THE COUNTRY WITH
CRASHING UPPER HEIGHTS, ACTIVE ONSHORE FLOW WITH FAVORABLE
THICKNESS DIFLUENCE IN THE NOSE OF THE 250MB JET AND A RATHER
DRAMATIC DROP IN SNOW LEVELS. EXPECT VERY HEAVY SNOWFALL FROM THE
COASTAL RANGES OF WA/OR INTO THE CASCADES AND ACROSS MUCH OF
NORTHERN CA, WHILE SPREADING INTO THE INTERIOR NW AND NORTHERN
INTER-MOUNTAIN WEST. ON MON, THE OPEN WAVE TROUGH DIGGING SOUTH
WILL GRADUALLY BEGIN TO CLOSE OF A MID TO UPPER LOW FROM NORTHERN
TO CENTRAL CA. THE SWRLY UPPER DIFLUENT FLOW ALOFT SHOULD YIELD
SNOW FROM THE SIERRA AND SOUTHERN CA MTNS ACROSS NV INTO THE
TETONS WITH THE GUIDANCE PINPOINTING SIGNIFICANT AMOUNTS OVER THE
CENTRAL SIERRA. THEN ON TUES, THE CLOSED 500MB LOW WILL SLIDE
ACROSS SOUTHERN CA INTO THE DESERT SW. A GRADUAL LOSS OF PAC
MOISTURE TRANSPORT IS EXPECTED THROUGH ENOUGH CONTENT SHOULD BE
AVAILABLE WITH THE ENHANCED LARGE SCALE LIFT FOR SNOW
ACCUMULATIONS FROM THE SOUTHERN SIERRA/SOUTHERN CA MTNS TO PARTS
OF THE FOUR CORNERS TERRAIN. 

...INTERIOR NEW YORK AND CENTRAL/NORTHERN NEW ENGLAND...

THE COMBINATION OF A SHALLOW COLD AIR MASS ATTEMPTING TO HOLD ON
AND THE ARRIVAL OF ANOMALOUS MOISTURE SURGE WILL YIELD FROZEN
PRECIP ACROSS MOST OF NORTHERN AND CENTRAL NEW ENGLAND ON SUN. THE
DEEPENING LOW PRESSURE SYSTEM NEAR THE UPPER GREAT LAKES IS
USHERING DOWNSTREAM A TROPICAL PLUME OF MOISTURE TOWARD THE NERN
QUAD OF THE COUNTRY, WHILE WEDGING SURFACE HIGH PRESSURE BEGINS TO
GIVE WAY. THIS MOISTURE WILL OVERRUN INTO THE REGION AND SHALLOW
COLD AIR MASS FOR ICING AND SNOW. ALSO, POSSIBLE DEVELOPMENT OF A
WEAK COASTAL WAVE MAY HELP ENHANCE QPF AMOUNTS OVER THE REGION,
WHICH MAY ADD TO POSSIBLE ACCUMULATIONS. THE GUIDANCE HAS A SOLID
HANDLING OF THIS SCENARIO, WHICH INCLUDES ICING FROM PARTS OF
UPSTATE NY INTO VT/NH AND WESTERN MA AND SNOWFALL ACROSS VT/NH
INTO ALL OF MAINE.

THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT DAYS
2 AND 3.

MUSHER