Cold in Alaska, January 7 to 8, 2003

NORTH ALASKA FORECAST DISCUSSION
400 AM AST TUE JAN 7 2003

QUIET BEFORE THE STORM THIS MORNING. AT THE SURFACE, 974 MB LOW IN THE
EAST SIBERIAN ARCTIC CIRCULATING COLD AIR SOUTHWARD AND EASTWARD INTO
NORTHERN ALASKA...WEAK COLD FRONT PASSING THROUGH PRUDHOE BAY AND THE
EASTERN SLOPES OF THE BROOKS RANGE TOUCHING OFF LIGHT SNOW. BREAKAWAY
994 MB EAST OF THE MACKENZIE DELTA STEEPENING GRADIENT FOR SPEEDIER BUT
SUB-ADVISORY WESTERLIES AT BARTER ISLAND.  LEFTOVER 1004 MB LOW NEAR
LAKE CHANDALAR FOCUSING ADDITIONAL SNOW AND STEEPENING GRADIENT FOR SOME
GUSTY WINDS AND REDUCED WIND CHILLS OVER THE SOUTHERN SLOPES OF THE
EASTERN BROOKS RANGE. HIGH PRESSURE CENTERED IN THE WESTERN INTERIOR
NEAR KALTAG KEEPS THE REST OF THE FORECAST AREA IN GENERAL LOW FLOW.

NEXT PLAYER ON THE MAP IS A 959 MB LOW NEAR ADAK...WHICH WE WILL GET TO
KNOW WELL OVER THE NEXT FEW DAYS.

ALOFT...500 MB TROUGH WITH AXIS BARROW-MCGRATH NOW LIFTING NORTHWARD AND
EASTWARD. RIDGE ALOFT IS BUILDING WESTWARD FROM GULF OF ALASKA INTO
SOUTHERN BERING SEA...WITH DEEP CLOSED LOW OFF THE WESTERN ALEUTIAN TIP.
A SHORTWAVE WITH AXIS DENALI-VALDEZ WILL PUSH NORTHEASTWARD...WITH
POSSIBLE QUICKIE SHOT OF LIGHT SNOW FOR EASTERN 224/226 OVERNIGHT INTO
THE MORNING AS CYCLONIC VORTICITY ADVECTION MAXIMUM ROLLS OVER THE
ARCTIC FRONT. OTHERWISE...AIR MASS OVERHEAD IS GENERALLY DRY AND SKIES
MOSTLY CLEAR.

MODELS...ARE HOLDING THE MAIN STORY TOGETHER BUT SHOWING SOME
INCONSISTENCIES ON TIMING AND FEATURE PLACEMENT. MAIN STORY LIFTS TROUGH
ALOFT CLEAR OF THE STATE BY LATE TODAY WITH STRONG NORTHWEST-SOUTHEAST
RIDGE FROM BERING STRAIT TO THE SOUTHEAST PANHANDLE. ASSOCIATED
NEGATIVELY-TILTED TROUGH WRAPS AROUND A CLOSED LOW ALOFT SOUTHWEST OF
ADAK...AND THIS WILL MAINTAIN THE DYNAMIC ESCORT LOW FOR THE SURFACE LOW
CURRENTLY NEAR ADAK. AS THE RIDGE WILL BE SLOW TO RETREAT...MOVEMENT OF
THE ADAK LOW NORTHWARD INTO THE CENTRAL BERING IS FORECAST TO TIGHTEN
SURFACE PRESSURE GRADIENT RAPIDLY LATE TUESDAY BETWEEN BRISTOL BAY AND
NORTON SOUND...WITH THE TIGHT GRADIENT REACHING THE SOUTHERN CHUKCHI SEA
ON WEDNESDAY AND OVERSPREADING THE CHUKCHI SEA ON TUESDAY AS THE RIDGE
RELENTS. ETA IS MOST AGGRESSIVE WITH SYSTEM MOVEMENT...AVN HOLDING IT
BACK IN THE SOUTHERN BERING...AND NEITHER SOLUTION TRACKS PARTICULARLY
WELL WITH PREVIOUS RUNS. WELL BLEND THIS ROUND...AND EMPHASIZE FEATURES
THE MODELS HAVE IN COMMON: STRONG SOUTHERLY FLOW RE-ESTABLISHED OVER THE
STATE, WINDS FOLLOWED BY SNOW MOVING NORTHWARD UP THE WEST COAST, AND A
GENERAL WARMING TREND STATEWIDE FOR AN UNTIMELY END OF ICEBOX DELIGHTS.

NORTH SLOPE...TROUGH ALOFT LIFTING OUT AND RIDGE ALOFT BUILDING IN WILL
CLEAR SKIES FOR THE SHORT TERM. AS RIDGE PROGRESSES EASTWARD...RETURN
FLOW WILL PRODUCE A WARMING TREND...AND TIGHTER SURFACE PRESSURE
GRADIENTS WILL BRING UP WIND SPEEDS WEDNESDAY OVER WESTERN ARCTIC
COAST...AND THESE INCREASED WINDS WILL SHOW UP ON THE BEAUFORT COAST BY
THURSDAY MORNING. NO SIGNIFICANT SNOW WITH THIS OVER THE NEXT COUPLE OF
DAYS. WILL LEAVE WIND CHILL ADVISORIES IN PLACE FOR BEAUFORT SEA
COAST...AS TEMPERATURES IN THE 30S BELOW AND WINDS AT THE 15 MPH
ADVISORY THRESHOLD WILL PRODUCE AUTOMATIC ADVISORY LEVEL WIND CHILLS.

WEST COAST...BLIZZARD WATCH FOR CAPE ROMANZOF A GOOD CALL FOR NOW...AND
WILL EXTEND WATCHES UP THE COAST FOR ZONES 212 AND 213 FOR HIGH WINDS
THIS ROUND. CONVINCING ISSUE WILL BE COLD AIR DRAINAGE THROUGH NULATO
HILLS PASSES PROVIDING EXTRA WIND FOR 212...AND 213 IN TIGHTEST GRADIENT
DURING THE DAY ON WEDNESDAY. WILL START WITH HIGH WIND WATCHES...AND
INCLUDE TOUGH LANGUAGE ADDRESSING WIND CHILLS AND BLOWING SNOW AS WIND
SPEEDS PICK UP...WITH POSSIBILITY OF SNOWFALL DURING THE DAY ON
WEDNESDAY. WILL EVALUATE POSSIBLE BLIZZARD FOR 212/213 IN ADDITION TO
HIGH WIND CLOSER TO THE EVENT...BUT WILL ISSUE BLIZZARD WATCH FOR 211 TO
COVER GOLOVIN FOR SNOW AND WIND LATE WED AFTERNOON. FOR
MARINERS...STARTING GALES IN AREA 14 THIS MORNING AND TO AREAS 9A/9B BY
WEDNESDAY.

INTERIOR...ONE MORE COLD DAY TODAY...AND THEN MODERATING TREND ON
WEDNESDAY AS SOUTHERLY FLOW ALOFT BECOMES ESTABLISHED IN EARNEST. WILL
SET WEDNESDAY HIGH WIND WATCH FOR DELTANA FOR STRONG DRAINAGE AUGMENTED
DOWN-VALLEY WINDS. ALTHOUGH TEMPERATURES ALOFT WILL MODERATE
RAPIDLY...COLD VALLEY TEMPERATURES WILL COWER UNDER THE INVERSION UNTIL
MOMENTUM CAN SCOUR THEM OUT. FOR THE WESTERN INTERIOR...SOME LIGHT SNOW
WORKING UP THE NULATO HILLS FOR LATE WEDNESDAY/EARLY THURSDAY.

MEDIUM RANGE...MODELS STAYING REASONABLY CLOSE TOGETHER HOLDING RIDGE
ALOFT IN WESTERN CANADA...CLOSING OFF LOW ALOFT IN NORTHERN GULF OF
ALASKA WITH TROUGH EXTENDING NORTHWESTWARD TO CLOSED LOW ALOFT OVER
MAGADAN. PATTERN KEEPS FORECAST AREA UNDER GENERAL SOUTHERLY FLOW
THROUGH THE WEEKEND...FOR CLEARER SKIES IN THE EASTERN INTERIOR...SOME
CLOUDINESS IN THE WESTERN INTERIOR...OFFSHORE WINDS FOR THE NORTH
SLOPE...AND THE BERING STORM FILLING IN PLACE SLACKENING GRADIENTS AND
EASING WIND SPEEDS .

.AFG...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WATCH: ZONE 214 (TUE NIGHT) 211 (WED NIGHT)
         HIGH WIND WATCH: ZONE 212/213/223 (WED)
MARINE...GALE WARNING: AREAS 14/9B
         HEAVY FREEZING SPRAY: AREAS 14/9B
         BRISK WIND ADVISORY: AREA 9A

TS JAN 03