Prognostic Meteorological Discussion
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000
FXUS01 KWBC 201935
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
335 PM EDT MON OCT 20 2014

VALID 00Z TUE OCT 21 2014 - 00Z THU OCT 23 2014

...HEAVY RAIN EXPECTED ACROSS THE NORTHWEST, NORTHEAST, AND
FLORIDA KEYS OVER THE NEXT FEW DAYS...

THE MOST ACTIVE REGION THIS PERIOD CONTINUES TO BE THE PACIFIC
NORTHWEST, WHERE AN ONSHORE FETCH CONTINUES RELATIVELY UNABATED
FOR THE NEXT FEW DAYS.  THUNDERSTORMS WITH HEAVY RAINFALL ARE
ANTICIPATED WITH EACH FRESH COLD FRONT PASSAGE, WITH TOTAL
ACCUMULATIONS OF 5-7" SLATED OVER THE NEXT FEW DAYS -- WITH
LOCALLY HEAVIER AMOUNTS -- PER WEATHER PREDICTION CENTER (WPC)
RAINFALL FORECASTS.  ACROSS THE HIGHER ELEVATIONS OF NORTH-CENTRAL
WASHINGTON, SOUTHWEST MONTANA, AND CENTRAL IDAHO, MEASURABLE
SNOWFALL IS EXPECTED ACROSS HIGHER ELEVATIONS, INCLUDING PORTIONS
OF THE CASCADES AND ANACONDA RANGES.

PORTIONS OF SOUTHERN NEW MEXICO AND WESTERN TEXAS CONTINUE TO BE
UNDER THE THREAT FOR SCATTERED THUNDERSTORMS EACH AFTERNOON AND
EVENING THROUGH WEDNESDAY AS AN UPPER LEVEL DISTURBANCE AND ITS
ASSOCIATED COLD POOL ALOFT COMBINE WITH DAYTIME HEATING TO
DESTABILIZE THE ATMOSPHERE AND LURE GULF OF MEXICO MOISTURE UP THE
RIO GRANDE.

THE NORTHEAST WILL BECOME A NEW FOCUS FOR SHOWERS AND
THUNDERSTORMS FROM TUESDAY INTO THURSDAY AS A COASTAL LOW MEANDERS
OFFSHORE THE NORTHERN MID-ATLANTIC STATES, COUPLING WITH A
STRENGTHENING UPPER LEVEL LOW MOVING IN FROM THE WEST-NORTHWEST AS
IT DEEPENS.  THUNDERSTORMS WITH MODERATE TO HEAVY RAINFALL ARE
EXPECTED DUE AN INCREASINGLY ONSHORE FLOW FROM THE ATLANTIC ACROSS
NEW ENGLAND AND THE NORTHERNMOST MID-ATLANTIC STATES, WITH A
GENERAL 1-2" OF RAIN -- WITH LOCALLY HIGHER AMOUNTS -- EXPECTED
OVER THE NEXT FEW DAYS.

INFLOW INTO THE VICINITY OF A WEAK STATIONARY FRONT TO THE EAST OF
A DEVELOPING MONSOON DEPRESSION BETWEEN THE BAY OF CAMPECHE AND
THE NORTHWEST CARIBBEAN SEA IS EXPECTED TO SPAWN THUNDERSTORMS
WITH HEAVY RAINFALL ACROSS THE FLORIDA KEYS -- 2-3" OF RAIN ARE
FORECAST BY WPC, WITH LOCALLY HIGHER AMOUNTS POSSIBLE.  THE
NATIONAL HURRICANE CENTER (NHC) INDICATES A LOW MOVING ACROSS THE
BAY OF CAMPECHE HAS A 50/50 CHANCE OF BECOMING A TROPICAL CYCLONE
BY MIDDAY WEDNESDAY -- SEE THE LATEST TROPICAL WEATHER OUTLOOKS
FROM NHC FOR MORE ON THIS SYSTEM`S POTENTIAL FOR TROPICAL CYCLONE
DEVELOPMENT.

ROTH

GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$




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