High Wind in Alaska, January 22 to 24, 2003

NORTH ALASKA FORECAST DISCUSSION
400 AM AST WED JAN 22 2003

1040-PLUS MB HIGH PRESSURE OVER THE EASTERN SIBERIAN SEA PAIRED UP WITH
GARGANTUAN 1056 MB HIGH SOUTHEAST OF VICTORIA ISLAND...AND RIDGE EXTENDS
SOUTHWARD FROM THIS FEATURE INTO EXTREME SOUTHEASTERN YUKON TERRITORY.
IN BETWEEN...A SERIES OF WEAK MERIDIONAL TROUGHS OVER ALASKA...ONE FROM
NUNIVAK ISLAND NORTHWARD TO WAINWRIGHT...AND THE OTHER FROM THE KENAI
PENINSULA TO EAGLE. BOTH TROUGHS EXTEND NORTHWARD TO WEAK 1031 MB LOW
300 NM DUE NORTH OF PRUDHOE BAY IN THE CENTRAL BEAUFORT SEA. WEAK
TROUGHS PROVIDING ENOUGH FORCING FOR SOME LIGHT SNOW AND VFR CEILINGS
ALONG THE ARCTIC/BEAUFORT COAST...AS THEY GET READY TO WELCOME BACK THE
SUN FROM ITS 2-MONTH HIATUS TODAY. STRATUS ATTACK CONTINUES ON THE
NORTHWEST COAST...AND HAVE SET DENSE FOG ADVISORIES FOR CHUKCHI SEA
POINTS, BERING STRAIT, KOTZEBUE SOUND AND KOBUK/NOATAK VALLEYS.

ALOFT...HIGH BUILDING NICELY OVER CHUKOTKA WITH RIDGE EXTENDING EASTWARD
TO ANOTHER HIGH CENTER OVER THE MACKENZIE DELTA. FILLING CLOSED LOW
SITTING OVER KODIAK ISLAND PROVIDING ONLY DIMPLE IN AN OTHERWISE VERY
LOW FLOW REGIME. WEAK DYNAMICS ADDING UPWARD TUG ON ATMOSPHERE ALONG THE
NORTH SLOPE...AS A VERY GENTLE SHORTWAVE RIDES SOUTHEASTWARD ON THE EAST
SIDE OF THE CHUKOTKA HIGH. AT 700 MB...ATMOSPHERE VERY DRY WITH DEWPOINT
DEPRESSIONS EXCEEDING 10 C. A FEW SCRAPS OF HIGHER CLOUD LINGER OVER THE
EAST CENTRAL INTERIOR FROM FAIRBANKS TO FORT YUKON...AND IFR CEILINGS IN
STRATUS UNDER DESCENDING AIR IN THE WESTERN INTERIOR AT POINTS LIKE
KALTAG AND AMBLER. AT 850 MB...STRONGEST EASTERLY FLOW GENERALLY SOUTH
OF A FORT YUKON-SEWARD PENINSULA LINE...AND THIS IS THE ZONE OF
STRONGEST COLD ADVECTION FROM CANADA. THIS EASTERLY FLOW HAS NOT
SUCCEEDED IN LINING UP WITH COLDEST CANADIAN AIRMASS FURTHER TO THE
NORTH...THUS TEMPERATURE ADVECTION WILL BE SOMEWHAT UNDERSTATED FOR THE
TIME BEING.

MODELS...TELLING A FAIRLY CONSISTENT STORY...MAINTAINING HIGH ALOFT OVER
EASTERN SIBERIA/WRANGEL ISLAND...AND ZONAL TROUGH ALOFT IN THE GULF OF
ALASKA SOUTH OF 50 N. ATMOSPHERE WILL BE HIGHLY BAROTROPIC FOR THE NEXT
FEW DAYS...WITH SURFACE FEATURES LINING UP DIRECTLY UNDERNEATH THEIR
SPONSORS ALOFT. WITH STRONGEST LOW LEVEL FLOW GENERALLY FROM A FORT
YUKON-SEWARD PENINSULA LINE SOUTHWARD...COLDEST AIR IN THE TERRITORY
WILL NOT BE ADVECTED WESTWARD TOO QUICKLY. DOMINANT MECHANISM FOR
COOLING WILL THEREFORE BE RADIATIVE LOSSES...AND OUR COLDER AIR MASS FOR
THE NEXT FEW DAYS WILL BE A HOMEGROWN EVENT RATHER THAN AN IMPORT.

NORTH SLOPE...CLEARING AND DRYING UNDERWAY FOR WEDNESDAY AFTERNOON AFTER
WEAK TROUGH SLIDES BY AND SURFACE HIGH PRESSURE OVER CHUKOTKA EXTENDS
ITS LONG ARM EASTWARD. AS HIGH BUILDS OVER NORTHERN ALASKA...AND LOWS
STAY SOUTH OF THE ALEUTIANS...SURFACE PRESSURE GRADIENT WILL REMAIN
TIGHTISH WEDNESDAY AND THURSDAY FOR SOME BREEZY EASTERLY/NORTHEASTERLY
WINDS. THIS BRINGS RISK OF ADVECTION FOGS AND FLURRIES UNDER TINY
EMBEDDED SHORTWAVES IN THE FLOW ALOFT...BUT NO DEEP TEMPERATURE PLUNGE
FOR THE NEXT SEVERAL DAYS. WITH SPEEDY WINDS, HOWEVER, WIND CHILLS WILL
DIP TOWARDS 50 BELOW -- ESPECIALLY ALONG THE BEAUFORT SEA COAST ON
THURSDAY NIGHT.  MARINERS...WINDS WILL FLIRT WITH BRISK WIND THRESHOLDS
FOR THE WESTERN ARCTIC COAST LATE WEDNESDAY...AND WILL BE BREEZY BUT
BELOW ADVISORY THRESHOLDS ELSEWHERE. APPRECIATE HELP FROM BRW AGAIN THIS
EVENING TO KEEP FORECASTS ON TRACK.

WEST COAST...STRATUS AND WINDS ARE THE HEADLINES...AS DESCENDING AIR ON
EAST SIDE OF CHUKOTKA HIGH AND PRESSURE GRADIENT BETWEEN THIS HIGH AND
LOWS SOUTH OF THE ALEUTIAN CHAIN WORK IN TANDEM. CAN SEE CONTINUING
STRATUS/DENSE FOG PROBLEMS FOR THE NORTHERN BERING SEA/CHUKCHI SEA/KOBUK
VALLEY IN THE HEART OF DESCENDING AIR. WIND SPEEDS WILL HAVE AN
UP-AND-DOWN PATTERN FOR THE NEXT COUPLE OF DAYS...SPEEDING UP AND
SLOWING DOWN ON ROUGHLY 24 HOUR PERIODS AS HIGH BUILDS...AND LOWS
MAINTAIN THEIR STRENGTH...IN A BAROTROPIC ATMOSPHERE. THIS WILL BE MOST
NOTICEABLE FOR NORTON SOUND POINTS SOUTHWARD...AND HAVE LESS EFFECT TO
THE NORTH. AM EXPECTING ADVISORY LEVEL WINDS AT THE MOST...AND THESE
ONLY AT THE USUAL WINDY PLACES. MARINERS...HAVING MOST OF THE WEATHER
EXCITEMENT THIS ROUND...BUT WILL SPOIL THIS BY STRIKING GALE WARNINGS
FOR AREAS 14/9B AND HOISTING SMALL CRAFT/BRISK WIND PENNANTS
INSTEAD...WHICH WILL PROBABLY FLY FOR A COUPLE OF DAYS BEFORE SPEEDS
TAPER OFF. EXPECT ROUGH SEAS IN WESTERN AREA 14 WILL REMAIN ABOVE SMALL
CRAFT ADVISORY THRESHOLDS GOING INTO THE WEEKEND. -- THANKS OTZ -- FOR
YOUR FORECAST ASSIST THIS MORNING.

INTERIOR...WINDS OVER THE HILLTOPS...AND LOCAL BOUTS OF STRATUS AND FOG
WILL BE THE CHIEF ISSUES THIS ROUND...AS NO PRECIPITATION IS EXPECTED,
AND TEMPERATURES WILL RADIATIVELY COOL TO SEASONAL NORMS FOR
MID-JANUARY. PRESENT INTERIOR CLOUD COVER STILL PROBLEMATICAL...AS
SUBSIDENCE ALOFT NOT HAVING MUCH EFFECT. YUKON TERRITORY DID CLEAR
TUESDAY NIGHT SETTING THE TREND. WILL THEREFORE PUSH SERIOUS CLEARING
OUT TO WEDNESDAY EVENING  FOR INTERIOR ZONES. BREEZY EASTERLY WINDS MAY
HIT ADVISORY CRITERIA FOR HILLTOPS BORDERING THE YUKON/KOYUKUK VALLEYS
-- AND IN THE TANANA VALLEY -- STARTING TONIGHT AND CONTINUING THROUGH
THURSDAY...WITH BLOWING AND DRIFTING SNOW. LOW-LEVEL STRATUS FORMATION A
TOUGH CALL...BUT IN THIS PATTERN WOULD BE EAST OF A DELTA
JUNCTION-ARCTIC VILLAGE LINE UNDER DESCENDING AIR. COLD AIR IN CANADA
RELUCTANT TO CROSS BORDER WESTWARD WITHOUT SOME ADVECTIVE HELP...AND
WILL EXPECT COLDEST TEMPERATURES FOR THE NEXT COUPLE OF DAYS AT POINTS
ALONG THE CANADIAN BORDER FROM EAGLE NORTHWARD.

MEDIUM RANGE...EMCWF/UKMET NOW BUYING INTO YESTERDAYS AVN/MRF
SOLUTION...WHILE AVN/MRF TODAY TELL YET ANOTHER STORY. SHAKY RUN-TO-RUN
CONTINUITY BUILDING LITTLE CONFIDENCE IN MEDIUM RANGE FORECASTS...AND
LITTLE CHANGE TO EXTENDEDS ANTICIPATED FOR THIS ROUND. ALL SOLUTIONS
MAINTAINING SOME SEMBLANCE OF CLOSED HIGH ALOFT OVER CHUKOTKA...AND
BROAD CLOSED LOW IN THE SOUTHERN BERING SEA/NORTH PACIFIC STRADDLNG THE
ALEUTIANS BY EARLY IN THE WORK WEEK...WITH POLAR VORTEX WINDING UP
NORTHWEST OF HUDSONS BAY. THIS STABLE REX-BLOCK PATTERN WILL DO ITS
BAROTROPIC DEED: LITTLE CHANGE TO CURRENT WEATHER...MAINTAIN A DRY
PATTERN...AND LEAVE EASTERLY/NORTHEASTERLY WIND SPEEDS ACROSS THE
SOUTHERN INTERIOR AND WEST COAST AS THE MAIN FORECAST ISSUE THROUGH THE
WEEKEND...ALONG WITH RADIATIVE COOLING OF THE AIR MASS IN PLACE.

.AFG...WATCH/WARNING SUMMARY
PUBLIC...DENSE FOG ADVISORY: ZONES 207/208/209/210/213/217
MARINE...GALE WARNING: AREA 14
         HEAVY FREEZING SPRAY WARNING: AREA 9B
         SMALL CRAFT/BRISK WIND ADVISORY: AREA 9B

TS JAN 03