Wind Chill Advisory 77, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
415 AM AST THU JAN 25 2007

.DISCUSSION...
MUCH OF THE UNCERTAINTY OF THE PAST 2 DAYS IS NOW IRONED OUT.
YESTERDAYS YAKUTAT LOW IS NOW HEADED NORTHEASTWARD...OUT OF THE
YUKON TERRITORY. CIRCULATION AROUND THIS SYSTEM INCREASED OVER THE
SOUTHEAST INTERIOR YESTERDAY WITH SOME STATIONS MEASURING WEST
WINDS UP TO 30 MPH. THESE WERE FINALLY LETTING UP AROUND MIDNIGHT
UP AT EAGLE SUMMIT. SNOWFALL AROUND THE OLD YAKUTAT LOW IS
GRADUALLY ENDING OVER THE NORTHEAST INTERIOR AND EASTERN ARCTIC OF
ALASKA.

GENERAL CLEARING HAS TAKEN PLACE OVER THE SOUTH INTERIOR. SO FAR
THE LEADERS IN THIS MORNINGS COLD POOL ARE MCGRATH AND RUSSIAN
MISSION WITH -37F. NOTE THAT THE RUSSIAN MISSION PICKED UP A
LITTLE NORTH BREEZE...WHICH SENT THE MERCURY UP TO -14F IN 2 SHORT
HOURS.

CONSIDERABLE STRATOCUMULUS LINGERS OVER THE NORTHERN INTERIOR BUT
THIS IS EXPECTED TO CLEAR TODAY AS SOUTHERLY FLOW ALOFT SETS IN.
THE MOSTLY MVFR CLOUDS OVER THE INLAND COASTAL PLAIN OF THE WEST
ARCTIC WILL TAKE MORE TIME TO CLEAR BECAUSE THE ONSET OF EASTERLY
CLEARING WINDS WILL NOT HAPPEN UNTIL LATE TONIGHT.

THE LARGE NORTH PACIFIC STORM NOW ABOUT 200 MILES SOUTH OF DUTCH
HARBOR IS HANDLED SIMILARLY ON THE FORECAST MODELS. IT SHOULD BE
WEAKENING NEAR DALL POINT SATURDAY EVENING. THE WARMING AHEAD OF
IT IS WELL ON COURSE. THE MEDIUM RANGE GFS MODEL LOOKS MORE
REASONABLE TODAY...THE HIGH ALOFT DUE TO BE OVER YAKUTAT ON
TUESDAY IS NOW FORECAST TO BE A MERE 570 DECAMETER CENTER AT 500
MB. THIS IS AT THE HIGH END OF POSSIBILITIES BUT THE SIMILARITY OF
THE EUROPEAN MODEL FORECAST LENDS CREDENCE TO IT.

THE STRENGTH OF WINDS AROUND THE NORTH PACIFIC STORM...NOW DUBBED
LOW NUMBER 1...APPEARS THAT IT WILL BE AT GALE STRENGTH BUT NOT
EXTREME. THIS IS TRUE OF THE WEST COAST MARINE FORECASTS AND THE
EXPECTED CHINOOK OVER THE ALASKA RANGE INTO THE SOUTH INTERIOR.
WINDS OUT ON THE YUKON DELTA THIS EVENING AND TONIGHT SHOULD BE
NORTHEAST 20 TO 30 MPH AND CONSIDERABLE BLOWING SNOW IS
EXPECTED...BUT NOT ENOUGH FOR A BLOWING SNOW ADVISORY WHICH HAS A
THRESHOLD VISIBILITY OF 1/2 MILE OR LESS.

THE SUCCESSORS TO LOW NUMBER 1 ARE STILL SUPPOSED TO BE TWO IN
NUMBER...BUT THE DETAILS ON THESE SYSTEMS ARE MURKY. THE GFS
FORECASTS LOW NUMBER 2 TO REACH DUTCH HARBOR AS A 975 MB CENTER ON
SATURDAY AFTERNOON. THE ACTUAL ORIGINS OF THIS EXPECTED SYSTEM ARE
NOT CREDIBLY APPARENT ON THE GOES SATELLITE IMAGERY...WHICH MEANS
THAT THE FORECAST IS SUSPECT. NUMERICAL MODELS STRUGGLE IN FAST
CHANGING SITUATIONS SUCH AS THIS...A RELATIVELY SMALL PERTURBATION
TO THE ANALYSIS CAN GROW INTO A SIGNIFICANT DISTURBANCE IN THE
FORECASTS. THE IMAGERY DOES SHOW SOME FORM OF A DEVELOPING LOW
NEAR 40N 175E...BUT THE SURFACE PRESSURE FIELD DOES NOT LOOK LIKE
IT IS IN SYNC WITH THIS YET.

LOW NUMBER 3 IN THIS SERIES IS FORECAST BY THE GFS TO BE A 956 MB
STORM JUST WEST OF NIKOLSKI ON MONDAY AFTERNOON. THE SOURCE REGION
FOR THIS FORECAST LOW IS NOT AT ALL CLEAR. TO ACCEPT THIS FORECAST
WOULD BE AN ACT OF GREAT FAITH. LOWS NUMBER 2 AND 3 WILL...IF THEY
MATERIALIZE...BRING LOTS OF WIND...PRECIPITATION AND WARMING TO
SOUTHWEST ALASKA...AND WARM SOUTH WINDS INTO MUCH OF THE INTERIOR.
INDEED...THIS OUTCOME MAY MATERIALIZE...BUT THE DETAILS AND
CAUSATIVE WEATHER SYSTEMS REMAIN TO BE SEEN.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NORTHERLY GALES BERING
STRAIT TO SAINT LAWRENCE ISLAND SATURDAY AND SATURDAY NIGHT.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
GALE WARNING FOR PKZ210.

BRISK WIND ADVISORY FOR PKZ200-PKZ210-PKZ220.
&&

TF JAN 07