Prognostic Meteorological Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4
000
FXUS01 KWBC 200841
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
341 AM EST THU NOV 20 2014

VALID 12Z THU NOV 20 2014 - 12Z SAT NOV 22 2014

...ARCTIC AIR WILL HOLD A GRIP ON THE CENTRAL AND EASTERN
U.S...BUT TEMPERATURES SHOULD BEGIN TO MODERATE HEADING INTO THE
WEEKEND...

...HEAVY SNOW BANDS WILL CONTINUE TO SET UP DOWNWIND OF THE LOWER
GREAT LAKES...

...ACCUMULATING SNOWS EXPECTED IN THE CASCADES LATE THIS WEEK...

...PRECIPITATION WILL MAKE A RETURN TO TEXAS AND THE LOWER
MISSISSIPPI VALLEY...

ARCTIC AIR WILL CONTINUE TO HOLD A GRIP ON THE CENTRAL AND EASTERN
U.S....BUT THE BELOW NORMAL TEMPERATURES FROM THE GREAT PLAINS TO
THE ATLANTIC COAST SHOULD BEGIN TO MODERATE HEADING INTO THE
WEEKEND.  WITHIN THE FRIGID AIRMASS...STRONG WINDS IN THE WAKE OF
A CLIPPER SYSTEM LIFTING INTO CANADA SHOULD RAMP UP LAKE EFFECT
SNOWS ON THURSDAY...WITH THE HEAVIEST SNOW BANDS EXPECTED TO SET
UP DOWNWIND OF THE LOWER GREAT LAKES.  SNOW SHOWERS ACROSS THE
GREAT LAKES SHOULD BEGIN TO DIMINISH ON FRIDAY AS A STRONG SURFACE
HIGH SLIDES EASTWARD AND CENTERS ITSELF OVER THE OHIO VALLEY.

A SERIES OF PACIFIC SYSTEMS WILL BRING UNSETTLED WEATHER INTO THE
WESTERN U.S. LATE THIS WEEK.  THE FIRST SYSTEM MOVING ONSHORE WILL
CAUSE MODERATE RAINS AND MOUNTAIN SNOWS ACROSS NORTHERN CALIFORNIA
ON THURSDAY BEFORE WEAKENING WHILE DROPPING TOWARDS THE SOUTHWEST
ON FRIDAY.  A SECOND...MORE ROBUST...PACIFIC SYSTEM APPROACHING
THE COAST WILL SPREAD PRECIPITATION INTO THE NORTHWEST BY EARLY
FRIDAY.  PACIFIC MOISTURE STREAMING INLAND...COMBINED WITH
OROGRAPHIC EFFECTS...SHOULD CAUSE HEAVY RAINS ALONG THE WASHINGTON
AND OREGON COASTS AND ACCUMULATING SNOWS IN THE HIGHER ELEVATIONS
OF THE CASCADES AND NORTHERN ROCKIES.

ACROSS THE SOUTHERN TIER OF THE NATION...MOISTURE SURGING
NORTHWARD OUT OF THE WESTERN GULF WILL FUEL INCREASING AMOUNTS OF
SHOWER AND THUNDERSTORM ACTIVITY ACROSS TEXAS AND THE LOWER
MISSISSIPPI VALLEY ON THURSDAY AND FRIDAY.  SOME STORMS COULD BE
STRONG TO SEVERE...AND AS THE MOISTURE AND PRECIPITATION SPREAD
NORTHWARD OVER A DENSE ARCTIC AIRMASS...FREEZING RAIN WILL BE
POSSIBLE FOR PORTIONS OF THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI
VALLEY.


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




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.