Blizzard in Alaska, March 9 to 10, 2015

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
536 AM AKDT MON MAR 9 2015

.DISCUSSION...
SHORT TERM...COLDER AND LESS ACTIVE WEATHER HAS ARRIVED IN
NORTHERN ALASKA THIS MORNING AS A LONGWAVE UPPER LEVEL TROUGH
SETTLES IN OVER THE STATE. THE FLOW ALOFT AND AT THE SURFACE WILL
CONTINUE TO WEAKEN INTO TONIGHT OVER NEARLY ALL OF THE FORECAST
AREA. THE ONLY EXCEPTION WILL BE THE EASTERN ARCTIC COAST WHERE A
STRENGTHENING SURFACE RIDGE ON THE NORTH SLOPE OF ALASKA WILL
PRODUCE GALE FORCE WESTERLY WINDS THROUGH TONIGHT WITH LOW
VISIBILITY IN BLOWING SNOW.

SNOW SHOWER ACTIVITY ACROSS MUCH OF THE INTERIOR WILL GRADUALLY
TAPER OFF AS LIGHT AND DRIER NORTHWESTERLY FLOW ALOFT DEVELOPS
OVER THE NEXT 24 HOURS. COOLING ALOFT IS ALSO PRODUCING SOME LIGHT
FLURRIES AS THE AIRMASS SQUEEZES OUT ANY EXISTING MOISTURE.
SNOWFALL AMOUNTS WILL BE VERY LIGHT...EXCEPT A FEW INCHES ARE
POSSIBLE TODAY IN THE EASTERN ALASKA RANGE A SMALL DISTURBANCE
MOVES NORTH FROM THE GULF OF ALASKA AND INTO THE YUKON TERRITORY.
DAYTIME TEMPERATURES WILL BE IN THE SINGLE DIGITS ABOVE AND BELOW
ZERO SOUTH OF THE BROOKS RANGE AND DROP WELL BELOW ZERO TONIGHT.
THE NORTH SLOPE WILL REMAIN BELOW ZERO AND FLIRT WITH WIND CHILLS
TO 50 BELOW FROM DEADHORSE EASTWARD.

.TUESDAY THROUGH WEDNESDAY...A BROAD 500 HPA TROUGH WILL PERSIST
OVER NORTHERN ALASKA THROUGH THE PERIOD. THE TROUGH WILL EXTEND FROM
THE HIGH ARCTIC TO MAINLAND AK INITIALLY AND THEN DIG SOUTH THROUGH
THE PERIOD AS A SHORTWAVE TROUGH MOVES FROM OVER WRANGEL ISLAND TUE
MORNING TO BRISTOL BAY LATE WED. THIS OPEN WAVE WILL HELP KEEP THE
COLD AIR ENTRENCHED THROUGH THE REST OF THE WORK WEEK WHILE
REINFORCING AND STRENGTHENING THE LONG WAVE TROUGH OVER MAINLAND AK.

THE COLD AIR IS FIRMLY IN PLACE ALOFT BY THE BEGINNING OF THE
PERIOD. 850 TEMPERATURES ARE A STEADY 20-25 C BELOW ZERO. OVER
FAIRBANKS...WE WILL HAVE TEMPERATURES 23-25 BELOW ZERO ALOFT AT 850
HPA...APPROACHING -2 STD DEV BASED OFF UA CLIMO...SO QUITE A COLD
AIR MASS ALOFT FOR THIS TIME OF YEAR. HIGHS AND LOW TEMPERATURES
WILL BE WELL BELOW THEIR SEASONAL NORMAL VALUES ACROSS THE WEST
COAST AND ALASKA INTERIOR.

AT THE SURFACE...A BROAD ELONGATED HIGH PRESSURE SYSTEM WILL PREVAIL
IN THE PERIOD. THE ELONGATED HIGH INITIALLY WILL STRETCH FROM THE
BERING SEA...TO OVER MAINLAND ALASKA...AND INTO THE YUKON TERRITORY.
HOWEVER...A COMBINATION OF LOW PRESSURE SYSTEMS APPROACHING AK WILL
WEAKEN THE HIGH OVER THE COURSE OF THE PERIOD. NAMELY...A SYSTEM
WILL BE STRENGTHENING AND MOVING NORTH IN THE NORTHERN PACIFIC
TOWARDS SOUTHEAST AND SOUTH CENTRAL AK WED...WHILE ANOTHER WILL BE
MOVING GRADUALLY EAST BUT STILL WEST OF THE KAMCHATKA PENINSULA.

THE COMBINATION OF THE COLD AIR MASS WITH A BENIGN LARGE SCALE
PATTERN WILL BE CONDUCIVE FOR QUIET AND DRY WEATHER WITH BELOW
NORMAL TEMPERATURES TUE THROUGH WED. WINDS WILL BE FAIRLY LIGHT
ACROSS MUCH OF THE AREA OF RESPONSIBILITY...EXCEPT FOR THE EASTERN
ARCTIC COAST WHERE MODERATE WEST WINDS WILL BE PRESENT BEFORE
DIMINISHING BY LATE TUE. WIND CHILLS APPROACHING 50 BELOW LOCALLY
ARE ANTICIPATED IN SOME PORTIONS OF THE CENTRAL AND EASTERN ARCTIC
COAST...MAINLY EAST OF NUIQSUT LATE MON OVERNIGHT AND TUE MORNING.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FOR AKZ204.

BRISK WIND ADVISORY FOR PKZ210-PKZ220-PKZ240-PKZ245.
&&

EWP/ET MAR 15