Wind Chill Advisory 46, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
212 PM AKDT FRI MAR 13 2009

DISCUSSION...

FORECAST MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM AND IN
GENERAL CONSENSUS THAT THE UNSEASONABLY COOL PATTERN WILL PERSIST
DEEP INTO NEXT WEEK AS THE MAIN UPPER LEVEL TROUGH REMAINS
ENTRENCHED OVER THE STATE.

A WEAK UPPER LEVEL TROUGH DRAPED ACROSS THE STATE IS KEEPING THE
MAIN JET STREAM OVER THE NORTH PACIFIC TODAY. THE OVERALL UPPER
LEVEL SYNOPTIC PATTERN WILL GRADUALLY BECOME MORE AMPLIFIED THIS
WEEKEND AS A VERY COLD UPPER LEVEL LOW OVER NORTHERN CANADA MOVES
ACROSS THE BORDER AND DIGS SHARPLY SOUTHWARD ACROSS THE STATE.
MEANWHILE OVER THE BERING SEA...A STRONG BLOCKING RIDGE WILL BUILD
NORTHWARD AND PREVENT ANY SIGNIFICANT WEATHER SYSTEMS FROM MOVING
INTO MAINLAND ALASKA INTO NEXT WEEK.

INTERIOR: TEMPERATURES ALOFT WILL SLOWLY FALL OVER THE NEXT FEW
DAYS WITH ALL MODELS INDICATING 850 MB READINGS PLUMMETING DOWN
INTO THE -30C OR COLDER RANGE OVER MOST OF NORTHERN ALASKA BY
SUNDAY. A MODERATE PRESSURE GRADIENT WILL PERSIST OVER MUCH OF THE
FORECAST AREA...AND THEN STRENGTHEN SOME THIS WEEKEND AS A 1040 MB
SURFACE HIGH MOVES INTO THE CHUKCHI SEA AND LOW PRESSURE REMAINS
LOCKED IN PLACE IN THE GULF OF ALASKA. THIS COMBINATION IS GOING
TO RESULT IN A FLURRY OF WIND CHILL ADVISORIES AND IN SOME CASES
WARNINGS AS CHILL READINGS FALL INTO THE 40 TO 60 BELOW RANGE.
SOME CALM AND SHELTERED VALLEY LOCATIONS WILL LIKELY SEE OVERNIGHT
AMBIENT TEMPERATURES DROP TO 40 BELOW OR COLDER. WINDS WILL LIKELY
REACH ADVISORY LEVEL OVER HIGHER TERRAIN AND IN CHANNELED AREAS
THIS WEEKEND AS WELL.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FOR AKZ201-AKZ217-AKZ218-AKZ219-AKZ220-
AKZ221.

BRISK WIND ADVISORY FOR PKZ210-PKZ220-PKZ225-PKZ230.
&&

MAR 09