High Wind in Alaska, October 24, 2013

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
203 PM AKDT THU OCT 24 2013

.SYNOPSIS...
ALOFT...
A RIDGE OVER EASTERN ALASKA AND NW CANADA WITH A TROUGH OVER THE
BERING AND NW PACIFIC WILL BECOME EVEN MORE HIGH AMPLITUDE OVER
THE WEEKEND. THIS IS EXPECTED TO CAUSE A STRONG CHINOOK OVER THE
ALASKA RANGE SAT NIGHT AND SUN...AND MORE STRONG WINDS AND HEAVY
PRECIPITATION ALONG THE WEST COAST AND WESTERN INTERIOR.
THIS IS ALSO EXPECTED TO KEEP TEMPERATURES ABOVE NORMAL INTO EARLY
NEXT WEEK WITH UP TO 20F ABOVE NORMAL ON THE WEEKEND.

850 MB TEMPERATURES RANGE FROM 0C IN THE SW INTERIOR TO -14C ALONG
THE ARCTIC COAST. TEMPERATURES RISE TO 0C TO -2C ALONG WEST COAST
AND SOUTHERN INTERIOR BY FRI PM...AND RISE SEVERAL DEGREES C
REMAINDER OF NORTHERN ALASKA FRI AND REMAIN WARM INTO SAT.

SURFACE...
HIGH PRESSURE BUILDING NORTH OF THE ARCTIC COAST IS CAUSING WINDS
TO TURN NE ALONG THE COAST NOW THROUGH TONIGHT. THIS WILL CAUSE
LIGHT SNOW SHOWERS TO DEVELOP DUE TO THE LOW LEVEL INSTABILITY
FROM THE VERY COLD AIR OVER THE WARM WATER. THAT WILL CONTINUE
INTO FRI BUT EXPECT ACCUMULATIONS TO BE UNDER AN INCH DUE TO THE
SHALLOW NATURE OF THE SHOWERS.

A 960 MB LOW IN THE SE BERING SEA WILL MOVE TO JUST EAST OF ST
MATTHEW ISLAND AS A 982 MB LOW BY 4PM FRI...AND TO THE BERING
STRAIT AS A 1011 MB LOW BY 4PM SAT...AND TO JUST WEST OF POINT
HOPE AS A 1013 MB LOW BY 4AM SUN. AN OCCLUDED FRONT STRETCHING
FROM THE LOW TO THE KUSKOKWIM DELTA TO KODIAK WILL MOVE TO ST
MATTHEW ISLAND TO NORTON SOUND TO DENALI BY 4AM FRI...TO THE
BERING STRAIT TO ARCTIC VILLAGE TO YAKUTAT BY 4PM FRI AND
DISSIPATING OVER THE ARCTIC COAST FRI NIGHT.

NE STORM FORCE WINDS ARE NOW OCCURRING OVER THE NORTHERN
BERING SEA AHEAD OF THE FRONT WITH GALES ALONG THE FRONT INLAND.
EXPECT SE GALES IN THE POISON TAIL AREA E OF THE LOW CENTER WHEN
IT MOVES OVER THE NORTHERN BERING. THIS WILL ALSO CAUSE MODERATE
CHINOOK WINDS THROUGH THE ALASKA RANGE THROUGH TONIGHT.

EXPECT SNOW AHEAD OF THE FRONT WITH LOW VISIBILITY FOR A FEW HOURS
IN BLOWING SNOW...CHANGING TO OR MIXING WITH RAIN ALONG AND SOUTH OF THE
FRONT. DO NOT EXPECT MORE THAN SEVERAL INCHES OF SNOW DUE TO THE
RAIN. POSSIBLE EXCEPTION IS THE SEWARD PENINSULA WHERE UP SLOPE
SNOW COULD CAUSE 4 INCHES OF SNOW FRI-SAT INLAND ALONG SOUTH
FACING SLOPES.

A LOW DEVELOPING NEAR YAKUTAT FRI WILL MOVE TO THE SOUTHERN YUKON
TERRITORY SAT. THIS WILL SPREAD A FEW INCHES OF SNOW TO THE
EXTREME SE INTERIOR FRI NIGHT AND SAT

A THIRD LOW DEVELOPING IN THE NORTHWEST PACIFIC WILL SPREAD ITS
FRONT INTO THE SOUTHERN BERING SAT AND SAT NIGHT. THIS WILL CAUSE
MORE PRECIP SW ALASKA SAT NIGHT AND SUN AND CHINOOK WINDS OVER THE
ALASKA RANGE SAT NIGHT AND SUN.

&&

.DISCUSSION...
GFS INITIALIZES BETTER THAN NAM AT 500 MB AND SURFACE ON THE DEEP
LOW NEAR COLD BAY AT 4AM...BUT THEY COME INTO LINE BY 4PM THU WITH
SIMILAR SOLLUTIONS THROUGH 4PM FRI. AFTER THAT TIME THE GFS
WEAKENS THE LOW IN THE NORTHERN BERING MORE QUICKLY AND MOVES IT
FURTHER NORTH THAN THE GFS. THIS APPEARS TO BE AS A RESULT OF THE
SHORT WAVE RIDGE AHEAD OF THE NEXT LOW ALOFT. PREFER THE GFS AS
THAT SECOND LOW ALOFT SHOULD BE DEEPER AS THE GFS DEPICTS.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FOR AKZ223-AKZ225-AKZ226-AKZ227.

HIGH SURF ADVISORY FOR AKZ213.

HIGH WIND WARNING FOR AKZ213.

HEAVY FREEZING SPRAY WARNING FOR PKZ225-PKZ230-PKZ235.

SMALL CRAFT ADVISORY FOR PKZ215-PKZ220-PKZ225.

STORM WARNING FOR PKZ210.

GALE WARNING FOR PKZ200.
&&

JB OCT 13