SHORT RANGE FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
253 AM EST WED JAN 14 2009
 
VALID 12Z WED JAN 14 2009 - 00Z FRI JAN 16 2009
 
BITTERLY COLD AIR WILL CONTINUE TO FILTER INTO THE CONUS FROM THE
ROCKIES TO THE MID-ATLANTIC...WITH THE MOST BRUTALLY COLD AIR
EXTENDING FROM THE NORTHERN PLAINS TO ILLINOIS AND INDIANA.  AS A
SURFACE HIGH OVER THE CANADIAN PRAIRIE SINKS SOUTHEASTWARD AND
BUILDS...A TIGHT PRESSURE GRADIENT WILL SET UP EAST OF THE
NORTHERN AND CENTRAL ROCKIES...RESULTING IN STIFF WINDS AND
EXACERBATING THE INTENSITY OF THE COLD.  OTHER PARTS OF THE GREAT
PLAINS CAN EXPECT LESS IN THE WAY OF A WIND CHILL
COMPONENT...HOWEVER...RADIATIONAL COOLING WILL COME INTO PLAY.
EITHER WAY...MORE DANGEROUSLY COLD TEMPERATURES ARE EXPECTED THIS
FORECAST PERIOD.  

THE LONGWAVE PATTERN FEATURES A FORMIDABLE UPPER LEVEL RIDGE...
WITH THE AXIS CENTERED OFF THE PACIFIC COAST FROM BRITISH COLUMBIA
TO CALIFORNIA...ALONG WITH BROAD UPPER LEVEL TROUGHING OVER THE
CENTRAL AND EASTERN UNITED STATES. THIS GENERAL PATTERN WILL
PERSIST THE NEXT COUPLE OF DAYS. THE NET RESULT WILL BE COLD AIR
EAST OF THE CONTINENTAL DIVIDE AND...RELATIVELY WARM AND DRY AIR
OVER MUCH OF THE WEST. CURRENTLY...THERE IS A BATCH OF UNSETTLED
WEATHER MOVING THROUGH THE MIDWEST THAT WILL BRING LIGHT SNOWS TO
THE OHIO VALLEY...PARTS OF THE NORTHERN MID-ATLANTIC AND COASTAL
NEW ENGLAND. ADDITIONALLY...BANDS OF SNOW WILL DEVELOP IN THE LEES
OF THE GREAT LAKES...ALTHOUGH THE ORIENTATION OF THE CONVECTIVE
BANDS WILL CHANGE AS THE FETCH CHANGES. OTHERWISE...FROM A QPF
PERSPECTIVE...THIS WILL BE A RELATIVELY DRY PERIOD.

SZATANEK



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