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Winter Weather Forecast Discussion
 
(Latest Discussion - Issued 0747Z Apr 19, 2015)
 
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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
347 AM EDT SUN APR 19 2015

VALID 12Z SUN APR 19 2015 - 12Z WED APR 22 2015


...DAY 1 IN WY...

CONFLUENT LOW-MID LEVEL FLOW UNDERNEATH NORTHWEST FLOW ALOFT LEADS
TO AREAS OF ENHANCED LOW-MID LEVEL RELATIVE HUMIDITY.  BNDRY LAYER
MOISTURE CONVERGENCE COMBINES WITH LIGHT UPSLOPE FLOW TO LEAD TO
LIGHT SNOW IN THE RANGES OF NORTHWEST WY.  A FEW ADDITIONAL INCHES
ARE EXPECTED WITH WEAK ASCENT OVER A LIMITED DURATION KEEPING
EXPECTED AMOUNTS LOW.

...DAY 2 IN WESTERN MAINE...

THE MODELS SHOW STRONG LOW-MID LEVEL WARM AND MOISTURE ADVECTION
PROGRESSING ACROSS MAINE THIS PERIOD.  PRECIPITATION WILL BE
WIDESPREAD AND THE MODELS SHOW SUFFICIENT DEEP LAYER TEMPERATURES
BELOW FREEZING FOR PRECIP TO START AS SNOW.  THE STRONG WARM
ADVECTION LEADS TO PRECIP CHANGING TO MIXED TYPES AND THEN RAIN AS
THE SOUTHEAST FLOW CONTINUES.  THE RISK OF HEAVY SNOW IS LOW DUE
TO THE GOOD AGREEMENT ON THE WARMING TREND IN THE MODELS.

DAY 3...

THE PROBABILITY OF HEAVY SNOW IS LESS THAN 10 PERCENT.

THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT DAYS
1-3.

PETERSEN