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NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
143 PM AKDT MON AUG 31 2015

.SYNOPSIS...
THE LONG WAVE PATTERN CONSISTS OF A TROUGH OVER THE EASTERN HALF
OF ALASKA AND A RIDGE OVER THE BERING SEA AND WEST COAST OF
ALASKA. THIS PATTERN IS BECOMING MORE PROGRESSIVE WITH THE RIDGE
BUILDING OVER MAINLAND ALASKA TUE THROUGH WED THEN PERSISTING INTO
THE WEEKEND. THIS WILL CAUSE A WARMING AND DRYING PATTERN OVER
EASTERN ALASKA FROM TUE THROUGH THU AND THEN REMAIN NEAR NORMAL
THROUGH THE WEEKEND. THE WEST COAST WILL SEE A RETURN TO WET
CONDITIONS WED AND THU WITH COOLING OVER THE WEEKEND.

A SHORT WAVE TROUGH FROM TOK TO ARCTIC VILLAGE WILL DISSIPATE OVER
THE EASTERN INTERIOR TONIGHT AND TUE. EXPECT SCATTERED RAIN AND
SNOW SHOWERS WITH THIS BECOMING ISOLATED TUE.

850 MB TEMPERATURES RANGE FROM +2C ALONG THE WEST COAST TO -6C
OVER THE CENTRAL NORTH SLOPE AND -4 OVER THE INTERIOR WITH
FREEZING LEVELS RANGING FROM 2000-3000 FEET EXCEPT FOR LESS THAN
1000 FT OVER THE NORTH SLOPE. ALL AREAS SEE A 2-4C RISE THROUGH
TUE...AND THEN RISE ANOTHER FEW DEGREES C WED WITH SURFACE
HIGH TEMPERATURES RISING AS WELL. FROST STILL LIKELY INTERIOR TONIGHT
AND TUE NIGHT AS SKIES CLEAR. 

SURFACE...
A 990 MB LOW 200 NM EAST OF INUVIK WILL MOVE EAST AND WEAKEN. AN
OCCLUDED FRONT WITH THIS LOW STRETCHING NORTH OVER THE BEAUFORT
SEA WILL MOVE SLOWLY EAST TUE AND WED. RAIN AND SNOW ASSOCIATED
WITH THIS FEATURE WILL FALL OVER THE NE SECTION OF ALASKA TONIGHT
THEN DIMINISHING TO SCATTERED SHOWERS TUE. EXPECT 2-4 INCHES OF
SNOW WITH THIS OVER NE ALASKA WITH THE HEAVIEST AMOUNTS IN THE
EASTERN BROOKS RANGE ABOVE 2000 FT. 

HIGH PRESSURE OVER THE WEST COAST AND WESTERN ARCTIC SLOPE OF
ALASKA WILL BUILD EAST OVER THE INTERIOR AND EASTERN ARCTIC SLOPE
TUE THEN MOVE EAST OVER NW CANADA WED AND THU. THIS IS CAUSING NW
WINDS 15G25 MPH UP THE TANANA AND OVER THE EASTERN BROOKS RANGE
PASS THROUGH THIS EVENING. THIS IS ALSO CAUSING WEST WINDS 30G40KT
OVER ZONE 204 WHICH WILL CONTINUE TONIGHT AND THEN DECREASING TUE.

A SURFACE LOW MOVING IN THE SOUTHERN BERING SEA TUE WILL MOVE TO
100 NM SOUTH OF GAMBELL BY 4PM WED AS A 1000 MB LOW AND TO 100 NM
NORTH OF GAMBELL AS A 1005 MB LOW BY 4PM THU. EXPECT WIDESPREAD RAIN
TO SPREAD NORTH ALONG THE WEST COAST WITH THIS SYSTEM WED AND THU
WITH A CHANCE OF RAIN IN THE WESTERN INTERIOR WED NIGHT AND THU.
WILL SEE EAST WINDS 30KT SPREADING NORTH OVER THE BERING SEA JUST
NORTH OF THE LOW. THIS SYSTEM COULD DEEPEN OVER THE CHUKCHI SEA
FRI AND SAT AND BRING A STRONG COLD FRONT EASTWARD ACROSS THE
ARCTIC COAST OVER THE WEEKEND...BUT THIS IS STILL VERY UNCERTAIN.

&&

.DISCUSSION...
MODELS INITIALIZE WELL AND SHOW SIMILAR SOLUTIONS THROUGH WED.
FROM WED THROUGH NEXT WEEK SEE SOME DIFFERENCE IN TIMING OF SHORT
WAVES/SURFACE LOWS...THOUGH THE LONG WAVE PATTERN IS GENERALLY
SIMILAR. PREFER THE GFS WHICH IS A BIT SLOWER AND DEEPER WITH THE
SURFACE LOW MOVING NORTH OVER THE BERING SEA WED AND THU AND OVER
THE CHUKCHI FRI.


COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
HIGH SURF ZONE 204 THROUGH TUE.
POSSIBLE HIGH SURF ALONG ARCTIC COAST SAT AND SUN BUT STILL MUCH
UNCERTAINTY ON THAT SYSTEM.

&&

.FIRE WEATHER...
SLIGHT DRYING AND WARMING TUE AND MORE SO WED.

&&

.HYDROLOGY...
HIGH WATER REMAINS ON THE LOWER CHENA BUT IS NOW FALLING AS THE
DAM IS NOW RELEASING WATER DOWNSTREAM. 
RIVERS FALLING MOST OTHER AREAS NOW AS WELL.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY FOR AKZ204.

SMALL CRAFT ADVISORY FOR PKZ210-PKZ240.

GALE WARNING FOR PKZ245.
&&

$$

JB AUG 15

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