Heavy Snow in Alaska, April 24 to 26, 2008

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
540 AM ADT FRI APR 25 2008

.DISCUSSION...
A 500 MB LOW NEAR CAPE LISBURNE THIS MORNING WILL CONTINUE TO
SLOWLY DIG INTO NORTHWEST ALASKA THROUGH TONIGHT. A TROUGH WILL
EXTEND SOUTH FROM THE CLOSED LOW TO NEAR BRISTOL BAY BY THIS
AFTERNOON. SOME OF THE ENERGY ASSOCIATED WITH THIS TROUGH WILL
DROP INTO THE GULF OF ALASKA AND INTERACT WITH A CLOSED LOW NEAR
40N 155W TO FORM A STRONG CLOSED LOW IN THE NORTHERN GULF BY
SUNDAY. TROUGHING WILL EXTEND NW FROM THIS CLOSED LOW ALONG THE
WEST COAST.

AT THE SURFACE...A 997 MB LOW PRESSURE JUST NORTH OF WRANGEL
ISLAND THIS MORNING WILL MEANDER AROUND AND CONTINUE TO SLOWLY
WEAKEN THROUGH TONIGHT AS IT BECOMES DISJOINTED FROM THE UPPER
LEVEL SUPPORT. THE COLD FRONT THAT HAS PUSHED EAST TO THE EASTERN
INTERIOR THIS MORNING IS IN THE PROCESS OF BECOMING NEARLY
STATIONARY AS THE SURFACE FRONT BECOMES PARALLEL TO THE UPPER
LEVEL FLOW.

INTERIOR...THE MOST SIGNIFICANT WEATHER DURING THE NEXT 24 TO 48
HOURS WILL BE ACROSS THE ALASKA RANGE. HEAVY SNOW IS EXPECTED ACROSS
THE WESTERN ALASKA RANGE TODAY AS MOISTURE CONTINUES TO OVERRUN THE
COLDER AIR BEHIND THE COLD FRONT.  SIGNIFICANT SNOWFALL STILL LOOKS
LIKELY ABOVE 3500 FT WEST OF THE PARKS HIGHWAY.  THE HEAVIER
SNOWFALL WILL LIKELY SPREAD EAST INTO THE WESTERN PARTS OF ZONE 226
(WEST OF ISABEL PASS TONIGHT AND SATURDAY). WILL EXPAND THE HEAVY
SNOW WARNING EAST INTO 226. ACROSS THE REMAINDER OF THE INTERIOR
THERE WILL BE AREAS OF RAIN AND SNOW TODAY THROUGH THE WEEKEND.
SOME STRONGER WIND IS ALSO POSSIBLE IN THE PASSES OF THE EASTERN
ALASKA RANGE. SO FAR THERE HAS NOT BEEN MUCH IN THE WAY OF WIND
AND WILL PUSH BACK THE START TIME OF THE ADVISORY TO NOON. THE
MODELS ARE STILL INDICATING ABOUT 40 KT WIND IN THE BOUNDARY LAYER
THROUGH 700 MB.

WEST COAST...COLDER THAN AVERAGE TEMPERATURES ARE EXPECTED THROUGH
THE WEEKEND AS THE AREA REMAINS UNDER THE INFLUENCE OF THE UPPER
TROUGH.  THE SIGNIFICANT MOISTURE REMAINS EAST OF THE UPPER TROUGH
AND ONLY ISOLATED TO SCATTERED SNOW SHOWERS ARE EXPECTED.

NORTH SLOPE...JUST BEHIND THE FRONTAL BOUNDARY THERE WILL BE AREAS
OF SNOW ALONG THE CENTRAL AND EASTERN BEAUFORT SEA COAST FROM ABOUT
NUIQSUT EAST AS WELL AS ACROSS PARTS OF THE EASTERN BROOKS RANGE.
A FEW INCHES OF SNOW IS LIKELY...WITH LOCALLY HIGHER TOTALS ACROSS
THE HIGHER ELEVATIONS IN THE BROOKS RANGE.

MID-RANGE...MUCH OF THE UPPER LEVEL ENERGY CURRENTLY ALONG THE NW
COAST WILL DIVE SOUTHEAST AND INTO THE GULF OF ALASKA. MODELS AND
ENSEMBLES SHOW CONSIDERABLE SPREAD BY EARLY NEXT WEEK...ESPECIALLY
ACROSS THE EASTERN BERING SEA. THUS FORECAST CONFIDENCE IS LOW TO
SAY THE LEAST. NO SIGNS OF ANY MAJOR WARM-UPS...AND WOULD EXPECT
TEMPERATURE TO HAVE NEAR TO A LITTLE BELOW AVERAGE...WITH THE
COLDEST TEMPERATURES LIKELY TO BE ACROSS WESTERN ALASKA.

&&

.FIRE WEATHER...COLDER AND UNSETTLED WEATHER WILL HELP TO MITIGATE
ANY FIRE WEATHER CONCERNS THROUGH THE WEEKEND.

&&

.HYDROLOGY...COLDER TEMPERATURES WILL SLOW THE SNOW-MELT ACROSS THE
INTERIOR THROUGH THE WEEKEND.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FOR AKZ226.

HEAVY SNOW WARNING FOR AKZ225-AKZ226.

BRISK WIND ADVISORY FOR PKZ245.
&&

CB APR 08