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Winter Weather Forecast Discussion
 
(Caution: Version displayed is not the latest version. - Issued 2013Z Apr 17, 2018)
 
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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
413 PM EDT TUE APR 17 2018

VALID 00Z WED APR 18 2018 - 00Z SAT APR 21 2018


DAYS 1-3...

...GREAT BASIN/FOUR CORNERS AND CENTRAL TO SOUTHERN ROCKIES...

SNOW WILL RETURN TO PARTS OF THE WESTERN TERRAIN ON THURS AND FRI,
WITH THE RETURN OF A POTENT SHORT WAVE TROUGH ARRIVING FROM THE
PAC. THE GLOBAL MODELS AND ENSEMBLES CAPTURE THIS FEATURE ARRIVING
INTO CENTRAL CA TOWARD THE DESERT SOUTHWEST. EXPECT A FEW INCHES
OF ELEVATED SNOWFALL A FOR THE CENTRAL TO SOUTHERN SIERRA INTO NV.
THEN ON THURS, A LARGE CLOSED 500 MB CIRCULATION WILL SPREAD
DOWNSTREAM THROUGH TH FOUR CORNERS REGION WILL YIELD SOME
DYNAMICALLY DRIVEN AND UPSLOPE SNOWFALL FROM THE SOUTHERN WASATCH
INTO THE CO ROCKIES, ESPECIALLY FOR THE SAN JUANS INTO THE SANGRE
DE CHRISTO RANGE. WPC STAYED CLOSER TO THE SLOWER ECMWF THAN THE
FASTER GFS.


...NORTHERN/CENTRAL PLAINS AND UPPER/MID MS VALLEY INTO GREAT
LAKES AND NEW ENGLAND...

A DYNAMIC SHORT WAVE TROUGH, PUSHING THROUGH WY/CO THIS AFTERNOON,
WILL EJECT OUT ACROSS THE UPPER PLAINS AND PROCEED DOWNSTREAM
THROUGH THE UPPER/MID MS VALLEY TO LAKE MICHIGAN ON WED. A CLOSED
MID TO UPPER LOW ACCOMPANYING THIS COMPACT SYSTEM WILL YIELD A
SWATH OF HEAVY SNOWFALL FROM NERN NE THROUGH NORTHERN IA INTO
SOUTHERN WI. MUCH OF THIS SNOW WILL BE RATHER INTENSE WITH HIGH
RATES, AS STRONG DYNAMIC COOLING TAKES PLACE WITHIN THE NWRN
PORTION OF THE LOW PRESSURE SYSTEM. THE GUIDANCE CAPTURES THIS
OVERALL SCENARIO WITH MINOR DETAIL SPREAD WITH THE HEAVIEST
SNOWFALL TOTALS ACROSS EXTREME NERN NE THROUGH NORTHERN IA.

THEN ON THURS AND FRI, THE MAIN SHORT WAVE TROUGH WILL BEGIN TO
INTERACT WITH A DIGGING NORTHERN STREAM JET. THE PARENT LOW
STREAKING ACROSS THE GREAT LAKES WILL WEAKEN, WHILE A TRIPLE POINT
JUST OFFSHORE OF SOUTHERN NEW ENGLAND DEEPENS AND LIFTS INTO THE
CANADIAN MARITIMES. THIS SHOULD YIELD OVERALL LIGHTER SNOWFALL
AMOUNTS ACROSS PARTS OF THE GREAT LAKES AND NEW ENGLAND.  

THE PROBABILITY OF FREEZING RAIN GREATER THAN 0.25 INCHES IS LESS
THAN 10 PERCENT DAYS 1-3.

MUSHER