Blizzard in Alaska, November 4, 2010

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
502 AM AKDT THU NOV 4 2010

.DISCUSSION...
MODELS IN FAIRLY GOOD AGREEMENT THROUGH ABOUT 48 HOURS BUT AFTER
THAT THE MODELS DIVERGE GREATLY. THE FIRST WAVE OF MOISTURE HAS
MOVED NORTH TO SOMEWHERE NEAR THE SOUTH SLOPES OF THE BROOKS RANGE
AND WEST TO NEAR GALENA. THIS HAS PRODUCED SPORADIC SNOWFALL OVER
NORTHERN ALASKA. THE CENTRAL TANANA VALLEY FROM FAIRBANKS SOUTH
SAW ZERO SNOWFALL FROM THIS WAVE. THE MAIN FRONT LOOKS TO BE ABOUT
AS GENEROUS TO THE INTERIOR AS THE FIRST WAVE WAS.

THE GRADIENT HAS TIGHTENED NICELY ON THE ARCTIC SLOPE WITH THE
EASTERN ARCTIC GUSTING TO NEAR 45 MPH CURRENTLY BUT VISIBILITIES
HAVE YET TO DROP EVEN NEAR BLIZZARD CONDITIONS AS OF YET AND
LIKELY WILL NOT UNTIL THE FIRST WAVE IS ABLE TO MOVE UP TO THE
ARCTIC COAST AND PRODUCE SOME SNOWFALL ALONG WITH THE STRONG WINDS
TO GET THE VISIBILITY DOWN TO BLIZZARD CRITERIA. THE WINDS SHOULD
START WINDING DOWN A BIT LATER TONIGHT. THE WESTERN ARCTIC NEEDS
TO BRACE THEMSELVES FOR THE INCREASED WIND THAT IS ABOUT TO BEGIN
ON THE WESTERN ARCTIC COAST LATER TODAY. THESE NORTHERLY WINDS
ARE GOING TO CAUSE HIGH SURF IN THE AREA AROUND POINT HOPE AND
MUCH EROSION TO THE BEACH HAS ALREADY TAKING PLACE.

THE ONLY CONCERN FOR THE WEST COAST IS THE FACT THAT NORTHERLY
WINDS WILL AGAIN START BACK UP TO SAY NORTHERLY AT ABOUT 30 TO 35
KT THROUGH THE BERING STRAIT TONIGHT AND FRIDAY. T

HE MODELS ARE IN
GOOD AGREEMENT AT THE START OF THE MEDIUM RANGE SAT NIGHT THAT AN
UPPER TROUGH WILL BE FOUND ALONG 160W AND WILL EXTEND SOUTHEAST
INTO THE NORTHERN GULF OF AK. THE MODEL SPREAD INCREASES
SIGNIFICANTLY EARLY NEXT WEEK WITH THE GFS AND IT'S ENSEMBLE MEAN
OUT OF PHASE BY TUESDAY AS THE GFS MOVES SOME LOW HEIGHT RIDGING
ACROSS THE MAINLAND AND THE ENSEMBLE MEAN HAS SOME BROAD
TROUGHING. ACROSS THE CENTRAL BERING SEA THE GFS HAS A TROUGH
WHERE THE ENSEMBLE MEAN HAS A RIDGE. THE ECMWF IS MORE IN LINE
WITH THE GFS ENSEMBLE MEAN THROUGH MONDAY...BUT THEN BECOMES OUT
OF PHASE BY TUESDAY. OVERALL FORECASTER CONFIDENCE DIMINISHES WITH
TIME AS DO THE NCEP RMOPS WHICH QUICKLY DROP TO BELOW AVERAGE
RELATIVE MEASURES OF PREDICTABILITY BY EARLY NEXT WEEK. IT LOOKS
LIKE MOST OF THE STORMINESS REMAINS ACROSS THE WESTERN AND CENTRAL
BERING SEA AND ALEUTIANS AND INTO THE GULF OF AK WITH NO MAJOR
STORM SYSTEMS EXPECTED TO IMPACT NORTHERN AK. TEMPERATURES WILL
TREND A BIT COLDER OVER THE WEEKEND INTO THE MIDDLE OF NEXT
WEEK...BUT NO MAJOR INTRUSIONS OF COLD AIR ARE FORESEEN THROUGH
DAY 7.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY FOR AKZ207.

BLIZZARD WARNING FOR AKZ204.

WINTER WEATHER ADVISORY FOR AKZ203.

HEAVY FREEZING SPRAY WARNING FOR PKZ220-PKZ225-PKZ230.

GALE WARNING FOR PKZ220-PKZ225-PKZ240-PKZ245.

SMALL CRAFT ADVISORY FOR PKZ200-PKZ210-PKZ220-PKZ230-PKZ235.
&&

CF NOV 10