Gale Warning 111, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
259 PM AST WED DEC 7 2005

.DISCUSSION...

ALOFT...AN AMPLIFIED PATTERN AT 500 MB CONTINUES ACROSS ALASKA AND
THE NORTHERN PACIFIC THIS AFTERNOON. A 497 DM LOW ANCHORS A TROUGH
THAT STRETCHES FROM WRANGEL ISLAND SOUTH TO THE CENTRAL ALEUTIANS.
A RIDGE BUILDING NORTH THROUGH THE EASTERN PACIFIC OCEAN HAS NOSED
INTO THE WESTERN YUKON ALONG THE ALASKA-CANADA BORDER.

MODELS BUILD THE RIDGE NORTHEAST INTO THE PACIFIC NORTHWEST WHICH
WILL HELP SHIFT THE 500 MB FLOW TO THE SOUTHWEST OVER THE NEXT 48
HOURS.

A 576 DM HIGH BUILDS OVER THE PACIFIC NORTHWEST BY THE WEEKEND
WHICH WILL BLOCK THE TROUGH FROM MAKING AN APPRECIABLE MOVE TO THE
EAST THROUGH THE CURRENT FORECAST PERIOD.

SURFACE...THE MAIN EVENT THIS AFTERNOON IS A 942 MB LOW OVER THE
CENTRAL ALEUTIANS AND HIGH PRESSURE OVER THE PACIFIC NORTHWEST.
A MODERATE CHINOOK HAS DEVELOPED BETWEEN THESE TWO FEATURES WITH
WITH SOUTH WINDS REACHING WARNING CRITERIA IN THE ALASKA RANGE.
NOT TO BE OUTDONE...WINDS OVER SAINT LAWRENCE ISLAND HAVE BEEN IN
THE 50 TO 55 KT RANGE. THIS HAS RESULTED FROM THE PRESSURE
GRADIENT BETWEEN THE ALEUTIAN LOW AND A 1050 MB HIGH IN SIBERIA.
THE HIGH WIND WARNING HAS BEEN REPLACED WITH A BLIZZARD WARNING AS
SNOW AND BLOWING SNOW WILL REDUCE VISIBILITIES TO NEAR ZERO AT TIMES.

SOUTH WINDS WILL BRING UPSLOPE SNOWS TO THE BROOKS RANGE. AMOUNTS
OVER THE 24 HOUR PERIOD WILL REACH WARNING CRITERIA OVER ALL ZONES
ON THE SOUTH SLOPES OF THE BROOKS RANGE.

THE ARCTIC FRONT HAS BEEN FORCED NORTH AND RESIDES FROM THE YUKON
DELTA ACROSS THE ALASKA RANGE. THIS HAS ALLOWED SNOW TO MOVE FROM
NORTH TO SOUTH OVER MOST AREAS WEST OF THE ALASKA RANGE. FREEZING
DRIZZLE HAS MIXED IN WITH THE SNOW NEAR KOTZEBUE SOUND AND POINTS
EAST AS THE WARM AIR OVERRIDES THE COLD DOME IN PLACE.

THE LOW WILL MOVE INTO BRISTOL BAY AND WEAKEN TO 960 MB BY
THURSDAY EVENING. THIS WILL CONTINUE A LIGHT SOUTH FLOW ACROSS THE
ALASKA RANGE BUT THE CHINOOK CONDITIONS WILL WEAKEN.
HOWEVER...LIGHT SNOW WILL CONTINUE THROUGH THE WEEK ACROSS THE
WEST COAST. WINDS WILL DIMINISH BY LATE THURSDAY OVER THE SAINT
LAWRENCE ISLAND AS THE LOW WEAKENS.

WEAK RIDGING OVER THE CENTRAL ARCTIC OCEAN COMBINED WITH THE
ALEUTIAN LOW WILL KEEP EAST WINDS BLOWING ACROSS THE ARCTIC COAST
THROUGH THE NEXT 48 HOURS. BLOWING SNOW ADVISORIES WILL EXTEND
INTO THURSDAY WHEN WINDS WILL DIMINISH FROM 20 TO 30 KTS TO 10 TO
20 KTS.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
HEAVY SNOW WARNING FOR AKZ206.

BLIZZARD WARNING FOR AKZ213.

HIGH WIND WARNING FOR AKZ225-AKZ226.

SNOW ADVISORY FOR AKZ218.

WIND ADVISORY FOR AKZ223.

WINTER WEATHER ADVISORY FOR AKZ215-AKZ216-AKZ217.

WINTER STORM WARNING FOR AKZ207-AKZ208-AKZ209-AKZ210-AKZ211-
AKZ212-AKZ219.

BLOWING SNOW ADVISORY FOR AKZ201-AKZ202-AKZ203-AKZ204-AKZ205-
AKZ214-AKZ220-AKZ221-AKZ222-AKZ224.

GALE WARNING FOR PKZ210.

BRISK WIND ADVISORY FOR PKZ200-PKZ210-PKZ215-PKZ220-PKZ225-
PKZ230.
&&

AT DEC 05