Cold in Alaska, March 12 to 13, 2015

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
402 PM AKDT THU MAR 12 2015

.DISCUSSION...
ALOFT AT 500 HPA...TROUGH OF LOW PRESSURE REMAINS OVER MAINLAND
ALASKA...WITH 500 DM LOW CENTERED NEAR TALKEETNA. LARGER OMEGA
BLOCKING PATTERN REMAINS UNCHANGED OVER THE PAST 24 HOURS WITH
TROUGH AXIS EXTENDING SOUTHWARD TOWARD HAWAII WITH RIDGE AXIS
CENTERED JUST WEST OF THE INTERNATIONAL DEADLINE AND THE WESTERN
CONUS. AT THE SURFACE...1030 MB HIGH REMAINS OVER EASTERN SIBERIA
WITH THE RIDGE EXTENDING EASTWARD INTO WESTERN AND NORTHERN
ALASKA. AN INVERTED TROUGH RUNS THROUGH THE SOUTHERN
INTERIOR...WITH ITS AXIS NOW STRETCHING FROM LAKE MINCHUMINA
STRETCHING SOUTHEASTWARD TO VALDEZ. THIS TROUGH IS AN EXTENSION
OF BROAD LOW PRESSURE OVER THE GULF...WITH A 988 MB LOW CENTER
LOCATED ABOUT 50 MILES SOUTHWEST OF YAKUTAT.

MODELS REMAIN IN FAIR TO GOOD AGREEMENT THROUGH THIS WEEKEND ON
THE LARGER SCALE FEATURES WITH A SHORT WAVE WILL TO ROUND THE
BASE OF THE LARGER LOW FRIDAY...LIFTING NORTHWARD AND CROSSING
INTO THE YUKON FRIDAY NIGHT. THE LOW WILL SLOWLY DRIFT
NORTHEASTWARD THROUGH THE WEEKEND WITH LINGERING TROUGHING
STRETCHING FROM NORTHEAST TO SOUTHWEST OVER THE EASTERN HALF OF
THE STATE BY EARLY SUNDAY MORNING. RIDGING WILL THEN SHIFT
WESTWARD OVER SOUTHEAST ALASKA FOR THE EARLY PARTS OF NEXT WEEK.
NAEFS STANDARDIZED ANOMALIES STILL DEPICTING H5 HEIGHTS AROUND 2.5
STANDARD DEVIATIONS BELOW NORMAL WITH H85 TEMPS UP TO 4 STANDARD
DEVIATIONS BELOW NORMAL FOR THE UPCOMING WEEKEND. AT THE
SURFACE...LOW PRESSURE OVER THE NORTHEASTERN GULF WILL MOVE MOVE
INLAND OVER THE WRANGEL MOUNTAINS THIS EVENING...WITH THE LOW
BROADENING AND WEAKENING AS IT DRIFTS INTO THE YUKON BY SATURDAY
EVENING. LARGER HIGH PRESSURE WILL REASSERT ITSELF OVER THE STATE
FOR THE UPCOMING WEEKEND...AS LOW PRESSURE SLIDES TO THE SOUTH OF
THE ALEUTIAN CHAIN...TO BE CENTERED AROUND 170 MILES SOUTH OF
SAND POINT BY SUNDAY AFTERNOON.

NORTH SLOPE...LITTLE IN THE WAY OF CONCERNS FOR THIS REGION...WITH
BROAD HIGH PRESSURE EXPECTED TO LINGER THROUGH AT LEAST THIS
WEEKEND. IT WILL REMAIN COLD AS H85 TEMPS REMAIN IN THE -20 TO
-30C RANGE...HOWEVER WINDS LOOK TO REMAIN LIGHT FOR AT LEAST THE
SHORTER TERM AND NOT EXPECTING MUCH IN TERMS OF WIND CHILL
CONCERNS FOR MOST LOCATIONS. THE EXCEPTION WILL BE OVER THE
EASTERN ARCTIC COAST WHERE 1019 MB HIGH PRESSURE WILL SLIDE ACROSS
THE ARCTIC PLAIN...AS BROAD LOW PRESSURE MOVES UP THE YUKON.
ENOUGH GRADIENT WILL EXIST HERE TO CREATE WIND CHILL CONCERNS
FRIDAY NIGHT INTO SATURDAY. OTHERWISE...WILL SEE SURFACE
TEMPERATURES RANGING BETWEEN 30 TO 45 BELOW AT NIGHT. THE WAVE OF
LOW PRESSURE ENTERING THE YUKON MAY JUST GRAZE EASTERN
ALASKA...BRINGING A CHANCE OF LIGHT SNOW OR FLURRIES TO THE
EASTERN ARCTIC COAST AND EASTERN BROOKS RANGE FROM LATE TONIGHT
THROUGH SATURDAY.

WEST COAST AND WESTERN INTERIOR...ISSUED A WIND CHILL ADVISORY FOR
ZONE 210 FROM THIS AFTERNOON THROUGH FRIDAY MORNING...AS SMALLER
SCALE LOW OVER KOTZEBUE SOUND HELPING TO CREATE ENOUGH OF A
GRADIENT TO SUPPORT 15 TO 25 MPH WINDS OVER THE NORTHERN SEWARD
PENINSULA WITH COLD ANTECEDENT AIR MASS. HIGH PRESSURE OVER
EASTERN SIBERIA WILL SLIDE EAST AND BROADEN/WEAKEN
TONIGHT...HELPING TO GRADUALLY DECREASE WINDS HERE LATE TONIGHT
INTO EARLY FRIDAY...DIMINISHING THE WIND CHILL THREAT.
OTHERWISE...CONTINUED QUIET CONDITIONS FOR THE REMAINDER OF THE
REGION AS HIGH PRESSURE ASSERTS ITSELF OVER THE WESTERN PART OF
THE STATE THIS WEEKEND. TEMPERATURES LOOK TO REMAIN COLD WITH
LOWS BETWEEN 25 TO 35 BELOW AT NIGHT WITH DIURNAL TEMPERATURE
SWINGS OF 20 TO 30 DEGREES DURING THE DAY. WILL HAVE TO WATCH
ANOTHER POTENTIAL WIND CHILL THREAT AS OVER SOUTHWEST ALASKA
SUNDAY INTO MONDAY...AS PRESSURE GRADIENT INCREASES HERE DUE TO
LOW PRESSURE SLIDING JUST SOUTH OF THE ALEUTIAN CHAIN AND COLD
AIR MASS STILL REMAINING IN PLACE. TEMPERATURES LOOK TO BEGIN TO
MODERATE EARLY NEXT WEEK AS SOUTH TO SOUTHEAST FLOW ALOFT BEGINS.

CENTRAL AND EASTERN INTERIOR...SUMMITS AND CHANNELED AREAS AROUND
THE YUKON FLATS AND EASTERN FOOTHILLS OF THE BROOKS RANGE WILL
CONTINUE TO SEE NORTHEAST WINDS BETWEEN 20 TO 35 MPH THIS
EVENING...DIMINISHING SLIGHTLY OVERNIGHT AS DIURNAL MIXING
CEASES. HELD OFF ON ANY HEADLINES FOR THIS REGION...AS
TEMPERATURES THERE LAST NIGHT ONLY COOLED ENOUGH TO SUPPORT
MARGINAL ADVISORY CONDITIONS. FOR THE REMAINING INTERIOR...WILL
SEE SOME PATCHY FOG TONIGHT AGAIN AS SUFFICIENT MOISTURE REMAINS
JUST OFF THE SURFACE. THIS MOISTURE COUPLED WITH A WEAK SURFACE
TROUGH OVER THE SOUTHERN INTERIOR ALSO HELPING TO TRIGGER SOME
SNOW SHOWERS AND FLURRIES OVER THE ALASKAN RANGE AND LOWER TANANA
VALLEY. EXPECTING COLD CONDITIONS TO PERSIST THROUGH THIS
WEEKEND...MODERATING FOR NEXT WEEK WITH LOWS FOR MANY LOCATIONS
BETWEEN 25 TO 40 BELOW WITH 20 TO 30 DEGREE SWINGS DURING THE DAY.
THE AFOREMENTIONED WAVE OF LOW PRESSURE PASSING TO THE SOUTH AND
EAST OF THE FORECAST AREA WILL BRING A CHANCE OF LIGHT SNOW TO THE
INTERIOR FROM LATE TONIGHT INTO FRIDAY NIGHT...MAINLY FROM A LINE
FROM BEAVER TO FAIRBANKS AND POINTS EAST. NOT EXPECTING MUCH FROM
THIS...PERHAPS UP TO AN INCH OR TWO OVER THE FORTYMILE
COUNTRY...UPPER TANANA VALLEY AND EASTERN ALASKA RANGE. THE BEST
LIFTING SUPPORT AND MOISTURE LOOKS TO REMAIN EAST OF THE BOARDER
ATTM.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FOR AKZ210.

BRISK WIND ADVISORY FOR PKZ210.
&&

NTS MAR 15