US HAZARDS ASSESSMENT
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300
PM EST JANUARY 13 2009
SYNOPSIS: STRONG HIGH PRESSURE OUT OF
CANADA ALONG WITH A PLUMMETING JET STREAM WILL BRING ARCTIC COLD TO MUCH OF THE
CENTRAL AND EASTERN U.S. ESPECIALLY BITTER COLD AIR WILL DOMINATE THE MIDWEST,
SOUTH, AND EAST ON FRIDAY AND SATURDAY, PRODUCING SUBZERO WIND CHILLS FOR MAJOR
METROPOLITAN AREAS FROM CHICAGO TO NEW YORK AND BOSTON. A DUO OF ALBERTA
CLIPPER LOWS WILL RAPIDLY PROGRESS EASTWARD ACROSS THE MIDWEST AND MID-ATLANTIC
FROM SATURDAY TO TUESDAY, SPREADING SNOW OVER THE MIDWEST AND NORTHEAST. HIGH
PRESSURE WILL DOMINATE THE WEST, BRINGING TRANQUIL WEATHER TO MOST OF THE
REGION, WHILE DEEP LOW PRESSURE WILL AFFECT SOUTHERN ALASKA ON FRIDAY AND
SATURDAY.
HAZARDS - HEAVY RAIN AND SNOW FOR SOUTHERN ALASKA
JANUARY 16 - 17.
- HIGH WINDS FOR SOUTHERN ALASKA JANUARY 16 - 17.
- MUCH BELOW NORMAL TEMPERATURES OVER THE EASTERN HALF OF THE NATION JANUARY
16-21.
- SEVERE DROUGHT CONTINUES IN THE SOUTHERN APPALACHIANS, WISCONSIN, THE
SOUTHERN PLAINS, AND PARTS OF THE WEST.
DETAILED
SUMMARYFOR FRIDAY JANUARY 16 - SUNDAY JANUARY
18: STRONG HIGH PRESSURE OVER THE MISSOURI VALLEY ON FRIDAY WILL TRACK
EASTWARD TO THE EASTERN SEABOARD ON SATURDAY. THE ARCTIC AIR COUPLED WITH BRISK
NORTHWESTERLY WINDS WILL PRODUCE DANGEROUSLY LOW WIND CHILLS ACROSS THE MIDWEST
AND EAST. TEMPERATURES WILL DROP WELL BELOW ZERO IN CHICAGO BY FRIDAY MORNING,
AND READINGS WILL NOT GET OUT OF THE TEENS IN NEW YORK AND BOSTON ON FRIDAY. AN
ALBERTA CLIPPER LOW WILL SPREAD SNOW ACROSS THE MIDWEST ON SATURDAY AND OVER
THE NORTHEAST ON SUNDAY. FRIDAY AND SATURDAY MORNING SHOULD SEE FREEZING
TEMPERATURES AS FAR SOUTH AS THE FLORIDA PENINSULA, POTENTIALLY DAMAGING CROPS
AND CITRUS.
HIGH PRESSURE AT THE SURFACE AND ALOFT WILL MAINTAIN MOSTLY DRY AND MILD
CONDITIONS ACROSS THE WEST.
ACROSS SOUTHERN ALASKA, A STRONG INFLUX OF MOIST AIR FROM THE GULF OF
ALASKA WILL BRING HIGH WINDS AND HEAVY RAIN AND SNOW ON FRIDAY AND SATURDAY.
FOR MONDAY JANUARY 19 - FRIDAY
JANUARY 23: A LOW THAT EXITED THE MID-ATLANTIC ON SUNDAY WILL LIKELY
INTENSIFY OFF THE NEW ENGLAND COAST ON MONDAY. THE LATEST OPERATIONAL EUROPEAN
(ECMWF) MODEL DEVELOPS AN IMPRESSIVE NOR'EASTER WHILE THE GFS SHOWS A MUCH
WEAKER SYSTEM. REGARDLESS OF THE DETAILS, THE LOW WILL HELP TO USHER IN ANOTHER
SHOT OF COLD AIR FOR THE EAST. BOTH MODELS SHOW LOW PRESSURE OVER NEW ENGLAND
ON TUESDAY, LEADING TO STRONG WINDS AND COLD AIR FROM THE EASTERN GREAT LAKES
TO THE EAST COAST. THIS SHOULD LEAD TO LOW WIND CHILL READINGS OVER THE I-95
CORRIDOR FROM BOSTON TO DC.
THE GFS MODEL SHOWS THE MEAN TROUGH DIGGING SOUTHWESTWARD TOWARD THE WEST
BY FRIDAY, WITH A LOW PRESSURE SYSTEM DEVELOPING IN THE TENNESSEE VALLEY. MUCH
COLDER AIR DROPS SOUTHWARD BEHIND THIS STORM AND COVERS MUCH OF THE WEST. THE
ECMWF SHOWS THE LOW FARTHER NORTH BUT CONCURS WITH THE FRESH BOUT OF COLD AIR
DROPPING OUT OF CANADA.
ANOTHER LOW MAY BRING A BOUT OF STRONG WINDS AND HEAVY RAIN AND SNOW TO
ALASKA AT THE START OF THIS PERIOD.
FOR SATURDAY JANUARY 24 - TUESDAY
JANUARY 27: MODELS SUGGEST A COLD WEATHER PATTERN FOR MUCH OF THE NATION
DURING THIS PERIOD, AS A BROAD UPPER LEVEL TROUGH DOMINATES THE LOWER 48.
FORECASTER: DOUG LECOMTE
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