High Wind in Alaska, October 28 to 29, 2002

NORTH ALASKA FORECAST DISCUSSION
400 AM AST MON OCT 28 2002

ITS A RATHER QUIET MORNING ACROSS MOST OF NORTHERN AK AS WEAK SURFACE
HIGH PRESSURE CENTERED OVER THE SOUTHEAST INTERIOR DOMINATES THE REGION.
THE LACK OF ANY STRONG SURFACE PRESSURE GRADIENTS HAS RESULTED IN
RELATIVELY LIGHT WINDS OVER MUCH OF THE FORECAST AREA. THE ONLY
SIGNIFICANT WEATHER PRODUCER OF CONCERN AT THE MOMENT IS A WEAK SURFACE
TROUGH WHICH EXTENDS SOUTHWEST FROM BANKS ISLAND TO THE CHUKCHI SEA.
SOME LIGHT SNOW AND FLURRIES ARE OCCURRING WITH THIS TROUGH ALONG THE
ARCTIC FRONTAL BOUNDARY. THE LULL IN THE WEATHER WILL BE SHORT LIVED
THOUGH AS A STRONG 960S MB LOW ENTERING THE GULF PUSHES A WEATHER FRONT
INTO SOUTHWEST AK MON AFTERNOON.

A HIGH PRESSURE RIDGE ALOFT REMAINS ACROSS MOST OF MAINLAND ALASKA THIS
MORNING. A WEAK VORTICITY MAXIMUM OVER THE BERING STRAIT IS PRODUCING
SOME HIGHER CLOUDS. THE BIG FEATURE IS THE LARGE UPPER LOW MOVING INTO
THE SOUTHWEST GULF. DEEPER MOISTURE AND DYNAMICS ASSOCIATED WITH THE
OCCLUDED FRONT ARE MOVING NORTH INTO SOUTHWEST ALASKA.

MODELS ARE IN GOOD AGREEMENT WITH THE TRACK AND STRENGTH OF THE GULF OF
AK LOW. THE CLOSED LOW AT 500 MB WILL MOVE NORTHWEST ACROSS THE ALASKA
PENINSULA MON NIGHT...AND EVENTUALLY WEAKEN TO A TROUGH OVER THE BERING
SEA TUE NIGHT. STRONG SOUTHERLY FLOW ALOFT WILL CONTINUE ACROSS THE
STATE AS HIGH PRESSURE ALOFT REMAINS ANCHORED OVER NORTHWEST CANADA.
WINDS WILL GRADUALLY INCREASE FROM SOUTH TO NORTH MON/MON NIGHT AS
SURFACE PRESSURE GRADIENT TIGHTENS ACROSS THE STATE. DUE TO
SIMILARITIES IN MODEL SOLUTIONS...PLAN TO STICK WITH ETA DUE TO
BETTER HANDLING OF TERRAIN.

NORTH SLOPE...THE WEAK SURFACE TROUGH ACROSS THE BEAUFORT SEA WILL
GRADUALLY WEAKEN AND DRIFT NE TODAY AND EXPECT LIGHT SNOW TO TAPER OFF
INTO TONIGHT. NORTHEAST WINDS WILL INCREASE TUE BRINGING AREAS OF
BLOWING SNOW. THE BEST DYNAMICS AND DEEPEST MOISTURE APPEAR TO BE
CONFINED TO THE WESTERN ARCTIC TUE. SO EXPECT SNOW TO SPREAD INTO THE
WESTERN AREAS TUE/TUE NIGHT. SET-UP IS FAVORABLE ENOUGH FOR A BLIZZARD
WATCH IN ZONE 201 FOR TUESDAY...ALTHOUGH TUESDAY NIGHT PRECIPITATION
MAY MIX WITH RAIN TO REDUCE THE BLIZZARD THREAT EARLY. ARCTIC
MARINERS...GALE WARNING WEST OF ICY CAPE FOR MON NIGHT AND EARLY TUE
MORNING WITH GRADUAL WIND REDUCTION BY MIDWEEK. SCAS HOISTED FOR ICY
CAPE TO CAPE HALKETT WITH HEAVY FREEZING SPRAY ALONG THE ENTIRE COAST.

WEST COAST...THE BIGGEST CONCERN WILL BE THE INCREASING N-NE WINDS
ACROSS THE REGION MON/MON NIGHT. ST LAWRENCE ISLAND AND CHUKCHI SEA
COAST COULD SEE WINDS UP TO WARNING LEVELS MON NIGHT. STRONG PUSH OF
WARMER AIR FROM THE SOUTH SHOULD KEEP PRECIPITATION IN THE LIQUID FORM
IN MOST AREAS. RAIN WILL SPREAD INTO YUKON DELTA LATER TODAY AND
CONTINUE NORTHWARD ALONG THE BERING STRAIT COAST MON NIGHT.
WIND ACTION TONIGHT WILL SET HIGH WIND WATCH FOR ZONE 213...AND
WIND ADVISORIES FOR NORTON SOUND AND THE YUKON DELTA TODAY...
AND TO CHUKCHI SEA COAST TONIGHT. MARINERS...GALE WARNINGS AT THE
MASTHEAD FOR ALL BUT KOTZEBUE SOUND...AND SCA PENNANT HOISTED HERE
FOR THIS ROUND.

INTERIOR...INCREASING SOUTH WINDS WILL BRING YET ANOTHER CHINOOK TO THE
AK RANGE. HIGH WIND WATCH FOR NORTH SLOPES OF THE RANGE STILL LOOK
REASONABLE. THE FLOW WILL REMAIN UNFAVORABLE FOR ANY
PRECIPITATION IN THE INTERIOR THE NEXT COUPLE OF DAYS.

MEDIUM RANGE...GRADUALLY SLACKENING SOUTHERLY FLOW ACROSS THE STATE
BY THE WEEKEND...AS BERING TROUGH RETROGRADES WESTWARD...AND CANADIAN
RIDGE RETREATS SOUTHWARD...AND POLAR VORTEX MOVES OVER NORTHERN HUDSON
BAY. PATTERN ENDS CHINOOK BY FRIDAY IN THE INTERIOR...CONTINUES TO
SMEAR WEST COAST WITH SHORTWAVE ENERGY AND PRECIPITATION...AND ALLOWS
GENERAL COOLING TREND THROUGH THE EARLY WEEKEND.

.AFG...WATCH/WARNING SUMMARY
PUBLIC...HIGH WIND WARNING: ZONES 225 AND 226
         BLIZZARD WATCH: ZONE 201
         HIGH WIND WATCH: ZONE 213
         WIND ADVISORY: ZONE 214
MARINE...GALE WARNING: AREAS 14, 9B, 9A, 10B, 11A-WEST
         HEAVY FREEZING SPRAY WARNING: AREAS 11A AND 11B
         SMALL CRAFT ADVISORY: 10A AND 11A-EAST

EWP OCT 02