Gale Warning 78, NWS Fairbanks, AK

NORTH ALASKA FORECAST DISCUSSION
230 PM ADT TUE SEP 27 2005

.DISCUSSION...
ANALYSIS...300MB HEIGHT PATTERN FEATURES A RIDGE FROM
BRITISH COLUMBIA UP TO ALASKAS INTERIOR. BROAD AND DIFFUSE AREA
OF LOW HEIGHTS COVERS THE BERING SEA...AND A 140KT CORE ZONAL JET
EXTENDS ALONG 45N FROM NORTHWEST PACIFIC ALL THE WAY TO EASTERN
GULF OF ALASKA WHERE IT RUNS INTO THE RIDGE MENTIONED ABOVE.
THE MOST PROMINENT BAROCLINIC FEATURE IS VERTICALLY STACKED
968MB LOW SOUTHWEST OF KODIAK IN THE CORNER BETWEEN THE
ZONAL JET AND THE RIDGE AT 300MB. GOES IR IMAGERY SHOWS ARC OF
MID AND HIGH LEVEL CLOUDS MOVING INTO FORECAST AREA AHEAD OF
OCCLUDED FRONT WHICH IS STILL OVER GULF OF ALASKA.
THE ARCTIC BOUNDARY EXTENDS ROUGHLY FROM CAPE LISBURNE TO FORT
YUKON AND THEN EAST INTO CANADA. ARCTIC VILLAGE IS WELL IN THE
ARCTIC AIR...AND HAD A HIGH TEMPERATURE OF 28F MONDAY.  12Z RAOBS
SHOWED 850MB TEMPERATURES OF -13C AT INUVIK AND 0C AT FAIRBANKS.
THE CLIMATOLOGICALLY REQUIRED SURFACE HIGH PRESSURE NORTH OF THE
ARCTIC COAST IS IN PLACE AND PROVIDING MODERATE EAST WINDS AND
MARINE LAYER STRATUS TO NORTH SLOPE ZONES. BOTH BARROW AND INUVIK
12Z RAOBS SHOWED DRY CONDITIONS THROUGH THE TROPOSPHERE ABOVE
THE MARINE LAYER INVERSION.

SYNOPTIC FORECAST...MODELS AGREE THAT 300MB RIDGE AXIS NOW OVER
BRITISH COLUMBIA AND MAINLAND ALASKA WILL DRIFT EAST AND INTO
THE INTERIOR OF CANADA OVER NEXT 24 HOURS. RESULT IS ZONAL JET
FLOW ALONG ABOUT 50N ACROSS ENTIRE NORTH PACIFIC WHICH LEAVES THE
FORECAST AREA UNDER A WEAK BAG OF LOW 500MB HEIGHTS...HEIGHTS
WHICH ARE A GOOD 20DM BELOW NORMAL FOR THIS TIME OF YEAR. 968 MB
LOW NOW SW OF KODIAK WILL DRIFT INTO NORTHERN GULF OF ALASKA AND
SLOWLY FILL OVER NEXT SEVERAL DAYS. SURFACE HIGH NORTH OF THE
ARCTIC COAST WILL STAY PUT FOR THE FORESEEABLE FUTURE.

NORTH SLOPE...MAIN ISSUE WILL BE WINDS ON SOUTH SIDE OF THE
SURFACE HIGH. GALE FORCE OR SMALL CRAFT ADVISORY CRITERIA WINDS
WILL BE A CONCERN THROUGH THE WEEK...BUT THERE IS NO MECHANISM TO
DROP MEANINGFUL AMOUNTS OF SNOW AND PRODUCE BLIZZARD CONDITIONS.
ANY SNOW WILL JUST BE FLURRIES FALLING FROM THE MARINE LAYER
STRATUS WHICH WILL NOT ADD UP TO ANYTHING.

WEST COAST...MAIN ISSUE WILL BE N OR NE WINDS ON BACK SIDE OF THE
LOW SW OF KODIAK...BUT NOTHING TOO STRONG BY WEST COAST STANDARDS
AND CERTAINLY MUCH WEAKER THAN LAST WEEKS STORM. CHANCE OF RAIN
OR MAYBE SNOW WITH ASSOCIATED OCCLUSION WHICH WILL MOVE INTO THE
AREA WED AND THEN STALL AND DISSOLVE IN PLACE THROUGH THE END OF
THE WEEK. PRECIPITATION AMOUNTS SHOULD BE LIGHT AS THERE IS NO
WAY TO BRING SIGNIFICANT MOISTURE IN FROM THE BERING SEA.

INTERIOR...GUSTY NORTHEASTERLY WINDS OVER THE USUAL SUMMITS
TONIGHT. THEN WIND SPEEDS BEGIN A LONG SLOW DECLINE WED AS THE
KODIAK LOW WEAKENS. A LITTLE RAIN OR SNOW POSSIBLE WITH PASSAGE
OF OCCLUDED FRONT BUT NO SIGNIFICANT ACCUMULATIONS. ARCTIC AIR
WILL REMAIN IN PLACE OVER NORTHERN INTERIOR...AND MORE MODERATE
TEMPERATURES WILL MOVE INTO SOUTHERN INTERIOR WITH THE OCCLUSION.
RESULT WILL BE MAINTENANCE OF A FAIRLY SHARP 850MB TEMPERATURE
GRADIENT ACROSS THE INTERIOR.

.AFG WATCH/WARNING/ADVISORIES...
PUBLIC...WIND ADVISORIES AKZ216...219...220...221.
MARINE...SMALL CRAFT ADVISORY PKZ200...235.
         GALE WARNING PKZ210...225...230...240...245.

ES SEP 05