Gale Warning 125, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
241 PM AKST SUN DEC 20 2009

.SYNOPSIS...
ALOFT A STRONG RIDGE OF HIGH PRESSURE CONTINUES TO BUILD INTO
EASTERN MAINLAND ALASKA. IN WESTERN ALASKA A SERIES OF LOW
PRESSURE SYSTEMS CONTINUE TO MOVE NORTH TOWARDS ST. LAWRENCE ISLAND.
MODELS ARE IN DECENT AGREEMENT INITIALLY...BUT BY 30 HOURS THE NAM
HAS THE SURFACE LOW NEAR THE WEST COAST 20MB WEAKER THAN THE OTHER
MODELS. THROUGH 84 HOURS THE ECMF...THE GFS AND THE UKMET ARE IN
REASONABLY GOOD AGREEMENT ALTHOUGH THE GFS DOES WEAKEN THE LOW
MORE QUICKLY. THE NAM APPEARS TO BE A SIGNIFICANT OUTLIER SO WE
THREW THAT OUT. OVER THE INTERIOR THE MODELS ARE IN DECENT AGREEMENT
THROUGH 60 HOURS WHEN THE GFS CONTINUES TO TRY AND MOVE THE RIDGE
OUT MORE QUICKLY.

&&

.DISCUSSION...

ACROSS THE WEST COAST...THE FRONTAL SYSTEM FROM 962 MB LOW JUST
WEST OF ST PAUL ISLAND AT 18Z IS PRODUCING BLIZZARD OR NEAR
BLIZZARD CONDITIONS ON THE SEWARD PENINSULA. THESE ARE EXPECTED TO
EXPAND NORTHWARD THROUGH THE EVENING. ON THE YUKON DELTA
TEMPERATURES CONTINUE TO WARM SO THE BLIZZARD WARNINGS MAY NEED TO
BE TRANSITIONED TO WINTER STORM WARNINGS OR HIGH WIND
WARNINGS...BUT AT THIS POINT WE WILL KEEP THEM BLIZZARD WARNINGS.
SNOW HAS BEGUN TO PICK UP IN THE WESTERN INTERIOR AND NULATO
HILLS. KALTAG IS REPORTING AROUND 2 MILES VISIBILITY AND SNOW...SO
THE WINTER STORM WARNINGS FOR HEAVY SNOW IN THE NULATO HILLS STILL
LOOKS GOOD. ANOTHER LOW DEEPENING SOUTH OF COLD BAY WILL MOVE TO
ST MATTHEW ISLAND BY MONDAY MORNING BRINGING ANOTHER ROUND OF SNOW
AND BLOWING SNOW. ONE POTENTIAL PROBLEM COULD BE WARM
TEMPERATURES. TEMPERATURES WILL REMAIN IN THE UPPER 20S TO LOW 30S
SO THAT COULD LIMIT BLOWING SNOW AND POSSIBLY BRING IN SOME
FREEZING RAIN.

ACROSS THE INTERIOR...A STRONG INVERSION HAS DEVELOPED WITH THE
RIDGE ALOFT. TEMPERATURES IN THE HILLS AROUND FAIRBANKS ARE AROUND
15 TO 20 DEGREES ABOVE ZERO...WHILE THE AIRPORT IS REPORTING 19
BELOW. SOME HIGH CLOUDS ARE EXPECTED TO MOVE INTO THE CENTRAL
INTERIOR THIS EVENING...WHICH MAY WEAKEN THE INVERSION SLIGHTLY
BUT IT IS EXPECTED TO STRENGTHEN AGAIN AND LAST THROUGH WEDNESDAY.
TUESDAY NIGHT INTO WEDNESDAY THE GFS BRINGS A SHORTWAVE ACROSS THE
INTERIOR...THIS COULD BRING SOME FREEZING RAIN TO THE INTERIOR.
THIS FEATURE IS MUCH WEAKER ON THE ECMF. THE ECMF CONTINUES TO
HAVE THE RIDGE THROUGH SATURDAY WHILE THE GFS BRINGS A LOW IN ON
THURSDAY AND MUCH COOLER TEMPERATURES. THE ECMF LOOKS MORE
CREDIBLE AS IT SEEMS UNLIKELY THE RIDGE WILL BREAK DOWN SO
QUICKLY. WINDS CONTINUE TO STAY UP IN AND JUST NORTH OF THE ALASKA
RANGE WITH THE CHINOOK FLOW AND THE TANANA VALLEY JET. REPORTS OF
GUSTS TO 42 MPH HAVE BEEN REPORTED IN HEALY. ANTLER CREEK HAS NOT
BEEN REPORTING BUT A GOOD FIRST GUESS IS NEARLY DOUBLE WHAT HEALY
REPORTS. WINDS HAVE ALSO BEEN STRONG AT FAREWELL LAKE IN THE
ALASKA RANGE WITH GUSTS THIS MORNING TO 52 MPH. WIND ADVISORIES
WERE ISSUED IN BOTH 227 AND 225 TO COVER THESE. THIS WIND WILL
VARY IN STRENGTH BUT IS EXPECTED TO CONTINUE AS LONG AS THE RIDGE
STAYS IN PLACE.

ACROSS THE NORTH SLOPE...THERE ARE CURRENTLY CLEAR TO PARTLY
CLOUDY SKIES AND DRY CONDITIONS. WINDS HAVE BEGUN TO PICK UP IN
THE WESTERN ARCTIC AND BROOKS RANGE AS THE LOW PRESSURE MOVES INTO
THE BERING SEA. BLOWING SNOW IS EXPECTED TO REMAIN BELOW ADVISORY
LEVEL...BUT THIS SHOULD BE WATCHED. AS THE RIDGE BUILDS IN A
WARMER AIR MASS MOVES INTO THE AREA. THIS WILL KEEP TEMPERATURES
ABOVE NORMAL THROUGH WEDNESDAY. WINDS WILL STAY UP IN THE EASTERN
ARCTIC WITH THE LOWS IN THE BERING THROUGH TUESDAY.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FOR AKZ225-AKZ227.

WINTER STORM WARNING FOR AKZ212-AKZ215-AKZ216.

BLIZZARD WARNING FOR AKZ207-AKZ209-AKZ210-AKZ211-AKZ213-AKZ214.

WINTER WEATHER ADVISORY FOR AKZ208.

GALE WARNING FOR PKZ200-PKZ210-PKZ215-PKZ220.

BRISK WIND ADVISORY FOR PKZ225-PKZ230-PKZ235-PKZ240-PKZ245.
&&

MKK DEC 09