Wind Chill Warning 11, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
428 AM AST SAT MAR 11 2006

.DISCUSSION...

ALOFT...HIGH AMPLITUDE PATTERN CONTINUES TO DOMINATE THE WEATHER
OVER NORTHERN ALASKA THIS MORNING. THIS AMPLIFICATION HAS SLOWED
THE EASTWARD PROGRESSION OF SYSTEMS TO A NEAR HALT. LONGWAVE RIDGE
IS LOCATED ALONG A LINE FROM KODIAK ISLAND NORTHWEST TO TIN CITY
AND NORTHWEST FROM THERE INTO EASTERN SIBERIA. REX BLOCK PATTERN
OF HIGH OVER LOW IS LOCATED TO THE EAST OF THIS LONGWAVE RIDGE. TO
THE WEST A 510 DM LONGWAVE TROUGH IS LOCATED FROM THE WESTERN
ALEUTIAN ISLANDS NORTHWEST TO THE KAMCHATKA PENINSULA. THIS
PATTERN PUTS MOST OF OUR FORECAST AREA IN THE NORTHWEST FLOW TO
THE EAST OF THE RIDGE AXIS BUT SOUTHERLY FLOW IS BEGINNING TO
IMPINGE FROM THE WEST. THIS PATTERN WILL NOT CHANGE APPRECIABLY
INTO EARLY NEXT WEEK OVER THE FORECAST AREA.

SURFACE...972 MB LOW LOCATED ABOUT 300 MILES NORTH OF ADAK WITH A
1052 MB HIGH CENTERED NEAR CHANDALAR. THE GRADIENT BETWEEN THESE
SYSTEMS IS CAUSING EASTERLY WINDS TO STRENGTHEN THROUGHOUT WESTERN
ALASKA. THE BERING SEA LOW IS ABOUT AS STRONG AS IT IS GOING TO
BECOME AND WILL FILL AS THE 500 MB TROUGH OVERTAKES IT TODAY. THE
RIDGE WILL SLOWLY SLIDE EAST AND REMAIN OF SIMILAR STRENGTH.
PRECIPITATION IS CONFINED TO ZONES 213 AND 214 AND WILL HAVE A
VERY HARD TIME MAKING ANY MORE EASTWARD PROGRESS AS THE 500MB
RIDGE CONTINUES TO GROW AHEAD OF THE SURFACE LOW. WITH BOTH THE
HIGH AND LOW PRESSURE SYSTEMS NOT MOVING MUCH IN THE NEXT
DAY...EXPECT WEATHER CONDITIONS TO REMAIN SIMILAR THROUGHOUT THE
WEEKEND OVER THE ENTIRE FORECAST AREA WITH WINDS SLACKENING AND
VISIBILITY IMPROVING OVER THE WEST COAST AS THE BERING SEA LOW FILLS.

MODELS...MODELS QUITE SIMILAR WITH DEPICTION OF THE 500 MB RIDGE.
GFS LOOKS MORE REALISTIC WITH SHORTWAVE TROUGH OVER NORTHEASTERN
ALASKA. AT THE SURFACE THE ETA HAS A BETTER HANDLE ON THE DEPTH OF
THE BERING SEA LOW AS THE GFS IS TOO WEAK. THE ETA ALSO DOES A
BETTER JOB RESOLVING THE HIGH OVER INTERIOR ALASKA. IN TERMS OF
EVOLUTION...THE ETA WANTS TO EVACUATE THE BERING SEA LOW INTO
SIBERIA BY MONDAY MORNING WITH THE GFS LEAVING A PERSISTENT
DECAYING FEATURE IN THE BERING SEA. THE ETA SOLUTION APPEARS
SUSPECT AS THE LOW...WHILE NOT VERY STRONG... SHOULD BE STRONG
ENOUGH TO AVOID BEING SWEPT NORTHWARD SO EASILY. THEREFORE THIS
PACKAGE LEANS TOWARDS THE GFS SOLUTION.

NORTH SLOPE...FRIGID AIR REMAINS ENTRENCHED OVER THE ARCTIC COAST
WITH TEMPERATURES THIS MORNING SOME 20F COLDER THAN NORMAL AT
BARROW. A SMALL BIT OF GOOD NEWS ARE THE WINDS... WHICH HAVE
CALMED DOWN SOME AS THE RIDGE MOVES OVERHEAD. HOWEVER...RETURN
FLOW TO THE WEST OF THE RIDGE IS BRINGING SOUTHERLY WINDS TO ZONES
201 AND 202.. THAT WILL ONLY SPREAD EASTWARD WITH TIME BRINGING
THE THREAT FOR MORE DANGEROUS WIND CHILLS TO THE NORTH SLOPE.
ALTHOUGH THE BERING SEA LOW WILL BE UNABLE TO SPREAD ANY
PRECIPITATION INTO OUR NORTHERN ZONES... IT WILL BE ABLE TO SPREAD
SOME WARMER AIR INTO THE AREA BRINGING TEMPERATURES BACK TO MORE
SEASONABLE READINGS BY EARLY NEXT WEEK.

WEST COAST...COLD AIR IS COMBINING WITH INCREASING WINDS TO BRING
DANGEROUS WIND CHILLS TO AREAS ALONG THE WEST COAST. THESE WIND
CHILL CONCERNS WILL BE RELATIVELY SHORT LIVED...HOWEVER... AS THE
BERING SEA LOW PUSHES WARMER AIR INTO THE REGION FROM THE SOUTH.
PAGM HAD BLIZZARD CONDITIONS YESTERDAY AFTERNOON AND IT APPEARS
THAT THE BLIZZARD CONDITIONS WILL RETURN VERY SHORTLY AS THE NEXT
BATCH OF SNOWFALL WILL MOVE INTO THE REGION SHORTLY AFTER 12 UTC
ALONG WITH WINDS THAT ARE NOW GUSTING OVER 50 MPH. PRECIPITATION WILL
HAVE LITTLE LUCK MAKING IT ONTO THE MAINLAND EXCEPT DOWN IN ZONE
214. CAPE ROMANZOF IS DISPLAYING JUST HOW MUCH WIND CAN COME FROM
A LARGE-SCALE PRESSURE GRADIENT OF 80 MB AS WINDS HAVE GUSTED
OVER 70 MPH ON NUMEROUS OCCASIONS. CONDITIONS THROUGHOUT OUR WEST
COAST ZONES WILL BEGIN TO IMPROVE TONIGHT AND TOMORROW AS THE
BERING SEA LOW WEAKENS AND WARMER AIR OVERSPREADS THE AREA.

INTERIOR...ANOTHER CLEAR AND COLD NIGHT THROUGHOUT THE INTERIOR AS
HIGH PRESSURE SETTLES IN FROM THE NORTH. THE PROXIMITY OF THE HIGH
HAS KEPT WINDS VERY LIGHT SO WIND CHILLS ARE NOT A PROBLEM THIS
MORNING. COLDEST 850 MB AIR IS LOCATED ALONG THE ALCAN BORDER
BENEATH A SHORTWAVE AT 500 MB. AS THIS FEATURE AND THE RIDGE TO
THE WEST SLOWLY MOVE EAST...WARMER AIR WILL GRADUALLY INFILTRATE
OUR INTERIOR ZONES. HOWEVER... THIS WARMING WILL BE SLOW TO
OCCUR... LIKELY SLOWER THAN WHAT THE MODELS ARE INDICATING.
WITH INTERIOR ALASKA LOCATED DIRECTLY UNDER THE RIDGE...
RADIATIONAL COOLING WILL BE MAXIMIZED EACH NIGHT ALLOWING
TEMPERATURES TO DROP WELL BELOW ZERO INTO EARLY NEXT WEEK.
DAYTIME HIGHS SHOULD WARM ABOUT 5F EACH DAY BRINGING MORE
SEASONAL TEMPERATURES BY MONDAY AND BEYOND.

EXTENDED...LONG RANGE MODEL SOLUTIONS ARE NOT IN GOOD AGREEMENT
WITH THE BASIC PATTERN AFTER EARLY THIS WEEK. ALL OF THE MODELS
SUGGEST THAT RIDGING WILL BE VERY HARD TO DISPLACE FROM ALASKA AND
THIS IS REASONABLE GIVEN THE THE AMOUNT OF BLOCKING IN THE CURRENT
PATTERN. THE EXACT RIDGE LOCATION AND STRENGTH..HOWEVER..IS VERY
DIFFERENT BETWEEN THE MODELS. THEREFORE WHILE IT APPEARS THAT
QUIET WEATHER SHOULD BE EXPECTED BY MIDWEEK OVER ALL OF THE
FORECAST AREA THE FORECAST BECOMES MUCH LESS CERTAIN AS WE MOVE
TOWARDS NEXT WEEKEND.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FOR AKZ201-AKZ207-AKZ209.

BLIZZARD WARNING FOR AKZ213.

GALE WARNING FOR PKZ200-PKZ210.

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

JMA MAR 06