Wind Chill Advisory 72, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
118 PM AST SUN JAN 7 2007

.DISCUSSION...
COLD CLOSED LOW ALOFT NOW APPROACHING ANCHORAGE WILL MOVE SOUTHEASTWARD
TO NEAR KETCHIKAN BY TUE AFTERNOON AS MAJOR PATTERN CHANGE TAKING
PLACE OVER THE THE REGION. BY FRIDAY HIGH NORTH PACIFIC RIDGE WILL
BE ESTABLISHED.

DEEP LOW PRESENTLY SOUTHWEST OF KAMCHATKA WILL LUMBER INTO THE
SOUTHWESTERN BERING SEA BY TUE MORNING. ASSOCIATED OCCLUSION WILL
BREAK AWAY FROM THE PARENT LOW AND MOVE INTO THE NORTHERN BERING
SEA ON TUE...THEN PROGRESSING EASTWARD WED WHILE DISSIPATING.
ADDITIONAL SFC LOW DEVELOPING OVER THE EASTERN BERING SEA BUT
TIMING/STRENGTH NOT POSSIBLE THIS FAR OUT. NOTE THAT DEEP CLOSED
LOW OVER THE WESTERN CANADIAN ARCTIC NOW BEING HANDLED MORE
CONSISTENTLY BY MODELS AND IMPACT OVER NORTHERN ALASKA WILL BE
MINIMAL WITH POSSIBLE EXCEPTION OF EASTERN ARCTIC COAST. BUILDING
SFC HIGH OVER INTERIOR WILL BE AT 1040 MB MONDAY EVENING AND 1044 MB
OVER THE SOUTHERN YUKON TUE AFTERNOON.

MODELS ALL AGREE ON THE GENERAL EVOLUTION BUT DIFFER QUITE A BIT
ON THE DETAILS...MOST OF WHICH IS NOT RESOLVABLE AT THIS

FOR THE NORTH SLOPE...RELATIVELY QUIET THRU TUE..WHEN WINDS WILL
START TO PICK UP THRU BROOKS RANGE PASSES AND FAR WESTERN ZONE
201.

FOR THE WEST COAST...IN THE SHORT TERM...WEAK TROF ALOFT NOW
APPROACHING ST LAWRENCE ISLAND NOT EXPECTED TO MAKE MUCH FURTHER
PROGRESS EASTWARD BEFORE DISSIPATING. FOR THE UPCOMING CHANGE...WE
WILL ISSUE BLIZ WATCHES FOR ZONES WERE SNOW WILL START ON
TUE...AND ANTICIPATE MOST OTHER COASTAL ZONES WILL REQUIRE WATCHES
FOR TUE NIGHT. WITH STRONG WARM ADVECTION WINDS WILL NOT BE AS
STRONG AS GRADIENT WOULD SUPPORT. ON THE OTHER HAND...THE WESTWARD
DRAINING VALLEYS...UNALAKLEET AND KOTZEBUE IN PARTICULAR...HAVE A
GOOD SUPPLY OF COLD AIR INLAND AND SO WILL HAVE (THE USUAL) SUPER-
GRADIENT WINDS.

FOR THE INTERIOR...MODELS CONTINUE TO HAVE TERRIBLE TIME HANDLING
CLOUDS/SNOW WITH THE COLD CORE LOW. HOWEVER...LOW EXITING MODEL
PERFORMANCE SHOULD IMPROVE STARTING MON. FOR NOW...WINDS HAVE
DIMINISHED THROUGH ALASKA RANGE PASSES...SO WIND CHILL ADVISORY
WILL END AS SCHEDULED. FAST MOVING LOW NOW NEAR YAKUTAT WILL KEEP
WINDS GOING UP THE TANANA VALLEY...SO THE WIND CHILL ADVISORY FOR
DOT LAKE AREA CONTINUES. COLDEST TEMPS IN CENTRAL AND EASTERN VALLEYS
WILL BE TUE AS RIDGE BUILDS ALOFT...DISSIPATING REMAINING CLOUDS.
LOWS OF 40 TO 50 BELOW SHOULD BE COMMON AND PER COOP MOS...MID 50S
BELOW IN THE USUAL COLD SPOTS NOT UNREASONABLE GIVEN COLD AMS.
SOME UNCERTAINTY ABOUT HOW MUCH SNOW WITH THE PATTERN CHANGE...MID
NIGHT ESPECIALLY FOR THE CENTRAL INTERIOR...BUT MODELS ARE
TRENDING TOWARD A SHARPER RIDGE...WHICH WILL BE MORE OF A CHINOOK
PATTERN. HOWEVER...NO MODEL HAS A DEEP CHINOOK...SO THERE IS
POTENTIAL FOR A COUPLE EPISODES OF SNOW.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WATCH FOR AKZ213-AKZ214.

WIND CHILL ADVISORY FOR AKZ223.

GALE WARNING FOR PKZ210.
&&

RT JAN 07