Blizzard Watch 10, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
501 AM AKST SUN DEC 14 2008

.DISCUSSION...
AN ACTIVE AND ENERGETIC PATTERN ACROSS THE HIGH LATITUDES SHOWS NO
SIGNS OF DIMINISHING ANY TIME SOON.  THERE WILL CONTINUE TO BE A
VERY STRONG EAST ASIAN JET THAT WILL STEER NORTH PAC SYSTEMS UP
ACROSS EASTERN RUSSIA.  AS LONG AS THIS LOW REMAINS IN PLACE AND AN
UPPER RIDGE REMAINS THE DOMINATE FEATURE IN THE INTERIOR THIS WILL
KEEP THINGS ACTIVE ALONG THE WEST COAST WITH CONTINUED BOUTS OF
STRONG WIND AND PRECIPITATION AT TIMES.

INTERIOR...OVERALL THE MOST BENIGN WEATHER THE NEXT FEW DAYS WILL BE
ACROSS THE INTERIOR. A STRONG RIDGE BUILDING ACROSS THE INTERIOR
WILL BRING 500 MB HEIGHTS WELL INTO THE 560S (DAM)...WHICH IS UP IN
THE UPPER TWO PERCENTILE FOR MID-DECEMBER.  THIS IS BRINGING COPIOUS
AMOUNTS OF WARM AIR ALOFT AND STRONG SUBSIDENCE INVERSIONS TO THE
INTERIOR.  LIKELY TO SEE 50+ (F) DEGREE TEMP SPREADS DURING THE NEXT
36 HOURS FROM THE COLDER YUKON FLATS TO THE HIGHER ELEVATIONS.
THIS IS ALL EVIDENT AT 13Z WITH A TEMPERATURE OF -13F AT THE
DENALI VISITOR CENTER (ELEVATION 1800 FT ASL) WHILE IT IS A
RELATIVELY BALMY +36F EIELSON CENTER (ELEV 3730 FT ASL). THE 850
MB TEMP ON THE MORNING PAFA SOUNDING WAS ALREADY UP TO -3C AND
SHOULD BE ABOVE FREEZING BY THE 00Z SOUNDING LATER TODAY. A
STRONG SHORTWAVE TROUGH KNOCKS DOWN THE RIDGE MONDAY AND AT LEST
TEMPORARILY USHERS A COLDER AIRMASS BACK INTO THE INTERIOR. THE
BIGGEST AFFECT WILL BE TO BREAK THE INVERSION AND RETURN TEMPS ON
THE HILLS TO MORE SEASONABLE LEVELS. THE PUSH OF COLDER AIR WILL
ALSO LIKELY BE ACCOMPANIED BY A SHORT PERIOD OF SNOW MONDAY
AFTERNOON AND EVENING...BUT IT IS VERY PROGRESSIVE AND UNLIKELY
THAT ANY ONE SPOT PICKS UP MORE THAN AN INCH OR TWO OF SNOW. THERE
WILL ALSO BE SOME WIND AND BLOWING SNOW ON THE SUMMITS...WITH A
SHORT WINDOW WHERE THE WIND AND/OR BLOWING SNOW COULD BECOME AN
ISSUE MONDAY AFTERNOON OR EVENING.

NORTH SLOPE...THE HIGH WIND EVENT ALONG THE NORTHWEST COAST HAS BEEN
WINDING DOWN EARLY THIS MORNING AND THE HIGH WIND WARNING WAS
ALLOWED TO EXPIRE WITH THE MORNING PACKAGE AS WINDS ARE NOW WELL
BELOW WARNING CRITERIA.  THE NEXT SHORTWAVE MOVES OUT OF SIBERIA AND
INTO THE WESTERN CHUKCHI SEA TONIGHT.  THIS WILL SPREAD SNOW BACK
INTO THE WESTERN ARCTIC COAST TONIGHT ALONG WITH AN INCREASE IN
WIND.  THERE SHOULD BE ENOUGH WIND AND SNOW TO WARRANT A WINTER
WEATHER ADVISORY STARTING UP LATE TONIGHT.  AS THE SYSTEM SWINGS
EAST THERE IS THE POSSIBILITY OF BLIZZARD CONDITIONS MONDAY
AFTERNOON INTO MONDAY NIGHT ALONG MUCH OF THE ARCTIC COAST...WITH
CONDITIONS IMPROVING WEST OF BARROW MONDAY EVENING.  FOR NOW WILL
HOLD OFF ON A BLIZZARD WATCH BUT WILL BRIEF THE INCOMING SHIFT THAT
THIS IS SOMETHING THEY MAY WANT TO CONSIDER DOING DURING THE DAY.

WEST COAST...BY FAR THE MOST ACTIVE WEATHER DURING THE NEXT 24 TO 36
HOURS WILL BE ALONG THE WEST COAST. IT WOULD APPEAR THAT THIS GO
AROUND THAT THE WIND WILL NOT BE AS STRONG AS THE LAST COUPLE OF
HIGH WIND EVENTS...BUT THERE WILL BE PLENTY OF MOISTURE. GIVEN THE
RECENT HISTORY OF WIND EVENTS AND THE ACCOMPANYING BLOWING SNOW
OPTED TO GO WITH MAINLY WINTER WEATHER ADVISORIES (ZONES
207-208-210-211-213)...AND A BLIZZARD WATCH FOR ZONE 209.  WILL ALSO
HAVE A WINTER STORM WATCH FOR ZONE 208 WHERE IN EXCESS OF 6 INCHES
OF SNOW IS POSSIBLE.  THE SHORTWAVE WILL QUICKLY EXIT TO THE EAST ON
TUESDAY WITH CONDITIONS RAPIDLY IMPROVING AND WINDS DIMINISHING.

MID-RANGE REMAINS A FORECAST HEADACHE WITH TERRIBLE CONTINUITY ON
THE DETAILS. ONE THING THAT SEEMS REASONABLY CLEAR THOUGH IS THE
VERY COLD LOW OVER CENTRAL AND EASTERN SIBERIA APPEARS TO BE
ANCHORED IN PLACE FOR THE FORESEEABLE FUTURE...WITH A SERIES OF
SHORTWAVES RACING OFF OF ASIA AND INTO THE WESTERN BERING SEA. THIS
IS LIKELY TO PROVIDE KEEP A FAIRLY HIGH ENERGY AND PROGRESSIVE
PATTERN OVER NORTHERN ALASKA. THIS WOULD RESULT IN GENERALLY WARMER
THAN NORMAL TEMPS FOR MOST OF THE CWA. THE PROSPECT OF RETROGRADING
HIGH AMPLITUDE RIDGE WAS STILL SUPPORTED BY HPC ON SAT.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WATCH FOR AKZ209.

WINTER STORM WATCH FOR AKZ208.

WINTER WEATHER ADVISORY FOR AKZ201-AKZ207-AKZ210-AKZ211-AKZ213.

GALE WARNING FOR PKZ225-PKZ230.

BRISK WIND ADVISORY FOR PKZ200-PKZ210-PKZ215-PKZ220-PKZ225-
PKZ230-PKZ235-PKZ235-PKZ240-PKZ245.

&&

CB/RT DEC 08