816
FXAK69 PAFG 312300
AFDAFG
NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
300 PM AKDT MON MAR 31 2025
SYNOPSIS
A 978 MB ARCTIC LOW IS MOVING ACROSS THE HIGH ARCTIC WITH THE
ASSOCIATED FRONT TRACKING EAST ALONG THE E ARCTIC COAST. A VERY
STRONG SUBTROPICAL RIDGE IS CURRENTLY OVER THE BERING SEA WITH
HEIGHTS AROUND 580 DAM. SEVERAL WAVES OF SNOWFALL WILL MOVE ACROSS
THE MAINLAND, WITH MIXED PRECIPITATION FROM THE SEWARD PENINSULA
SOUTHWARD AND LIGHT SNOW NORTH OF THE SEWARD PEN. SNOWFALL ACROSS
THE EAST-CENTRAL INTERIOR WILL COME IN ROUNDS, WITH THE FIRST
ALREADY IN THE PAST. THE SECOND AND MOST IMPRESSIVE ROUND IS ALREADY
MOVING IN TONIGHT INTO TUESDAY AND A THIRD DISTURBANCE MOVES IN ON
WEDNESDAY. TEMPERATURES SLOWLY RISE AS WARM AIR ADVECTION
COUNTERACTS EVAPORATIVE COOLING, BUT OVERALL TEMPERATURES STAY NEAR
OR BELOW FREEZING UNTIL TUESDAY AFTERNOON. THEY MAY THEN STAY ABOVE
FREEZING THROUGH WEDNESDAY AFTERNOON BEFORE COOLING WEDNESDAY NIGHT
ACROSS MUCH OF THE S INTERIOR BELOW 1000 FEET. THIS MAY RESULT IN
INCREASINGLY SLUSHY CONDITIONS TUESDAY AFTERNOON OR PERHAPS A
DIURNAL FREEZE-THAW CYCLE THAT RESULTS IN TREACHEROUS TRAVEL
CONDITIONS.
KEY WEATHER MESSAGES
CENTRAL AND EASTERN INTERIOR...
- SNOW INTENSIFIES THIS AFTERNOON WITH MODERATE TO HEAVY, WET
SNOWFALL TONIGHT THROUGH MIDDAY TUESDAY. SIGNIFICANT TRAVEL IMPACTS
ARE EXPECTED FOR THE TUESDAY MORNING COMMUTE, ESPECIALLY FOR CHENA
HOT SPRINGS AND BETWEEN FAIRBANKS AND DELTA JUNCTION.
- BLUSTERY SOUTHWEST WINDS GUSTING UP TO 30 MPH IN THE VALLEYS AND
UP TO 40 MPH AT ALONG HIGHWAY SUMMITS RESULT IN BLOWING SNOW
POTENTIAL, INCLUDING EAGLE SUMMIT.
- ANOTHER WAVE OF LIGHTER SNOW IS EXPECTED TUE NIGHT AND WED, BUT
WARMER TEMPS IN THE MID- TO UPPER-30S WED AFTERNOON ALLOW FOR
RAIN/SNOW MIX POTENTIAL AT ELEVATIONS BELOW 600 FT.
- WINTER WEATHER ADVISORIES REMAIN IN EFFECT FOR MOST OF SOUTHERN
INTERIOR ALASKA (EXCEPT SE ALASKA) FOR ADDITIONAL MULTI-DAY SNOWFALL
AMOUNTS OF 5 TO 12 INCHES. GREATEST AMOUNTS ARE EXPECTED NEAR EILSON
AFB WITH LOCALLY HIGHER AMOUNTS POSSIBLE AT THE HIGHEST ELEVATIONS
OF THE UPPER CHENA BASIN AND NEAR EAGLE SUMMIT.
WEST COAST AND WESTERN INTERIOR...
- SATURATED ONSHORE WINDS CONTINUE TO SUPPORT MIXED PRECIPITATION
AND FOG ACROSS THE YK DELTA TO THE SEWARD PENINSULA THROUGH TUESDAY
NIGHT.
- ADDITIONAL MULTI-DAY SNOWFALL ACCUMULATIONS WILL MAINLY BE IN THE
1 TO 4 INCH RANGE FOR THE WEST COAST AND WESTERN INTERIOR, BUT
AMOUNTS IN THE 5 TO 10 INCH RANGE ARE EXPECTED AT HIGHER ELEVATIONS
OF THE SEWARD PENINSULA, THE WESTERN INTERIOR, AND NULATO HILLS
BEFORE SNOW TAPERS OFF WEDNESDAY.
- TWO PERIODS OF GUSTY ONSHORE WINDS ARE EXPECTED. THE FIRST IS THIS
EVENING WITH WINDS UP TO 30 MPH THEN STRONGER GALE FORCE WINDS
TUESDAY NIGHT AND WEDNESDAY MORNING THAT COULD PUSH WATER OVER ICE,
BUT BLOWING SNOW POTENTIAL IS LIMITED BY WARM TEMPERATURES.
NORTH SLOPE AND BROOKS RANGE...
- THE COMBINATION OF FALLING AND BLOWING SNOW THAT BROUGHT
SUSTAINED VISIBILITY RESTRICTIONS TO BARTER ISLAND THIS MORNING
SUBSIDED BY MIDDAY AND IMPROVEMENT PERSISTED INTO THIS
AFTERNOON.
A BRIEF ~12 HOUR PERIOD OF STRONG WEST WINDS GUSTING UP TO 40-50 MPH
IS EXPECTED BETWEEN 3PM TUE AND 3AM WED, BUT THE LACK OF FALLING
SNOW SHOULD LIMIT VISIBILITY RESTRICTIONS.
FORECAST ANALYSIS AND DISCUSSION
SOUTHWEST WINDS BETWEEN A 978MB SURFACE ARCTIC LOW AND A 1037 MB
RIDGE OVER THE CENTRAL ALEUTIANS IS ADVECTING A PLUME OF
UNSEASONABLE MOISTURE INTO THE INTERIOR. THIS MOISTURE PLUME PUSHED
INLAND BEHIND THE SYSTEMS WARM FRONT THAT CROSSED MOST OF THE
INTERIOR LAST NIGHT. MULTIPLE DISTURBANCES EMBEDDED WITHIN THIS
SOUTHWESTERLY MOISTURE PLUME BRING SEVERAL ROUNDS OF SNOW TO
NORTHERN ALASKA THROUGH MIDWEEK. NAEFS GUIDANCE INDICATES A 24-HOUR
PERIOD (18Z MON-18Z TUE) WITH INTEGRATED VAPOR TRANSPORT VALUES
EXCEEDING 8 STANDARD DEVIATIONS ABOVE THE 1979-2009 CFSR CLIMATOLOGY
FOR THIS TIME OF YEAR. THIS UNSEASONABLY MOIST AIR MASS IS FUELING A
PROLONGED PERIOD OF ACTIVE WEATHER THAT IS REMINISCENT OF STORMINESS
LAST OCTOBER 20-21. HOWEVER, THE PRIMARY DIFFERENCE IS IT'S OCCURING
NEAR THE ANNUAL MAXIMUM SNOW COVER/SEA ICE EXTENT IMPLYING PRIMARILY
FROZEN/FREEZING PRECIPITATION. THE POSSIBLE EXCEPTION IS AT LOWER
ELEVATIONS DURING PEAK AFTERNOON HEATING SINCE WE ALREADY HAVE 5
MORE HOURS OF DAYLIGHT THAN IN OCTOBER, EXCEPT WHERE STEADY
PRECIPITATION SUSTAINS EVAPORATIVE COOLING. FREEZING FOG, MIST, AND
DRIZZLE WAS COMMON ALONG THE WEST COAST THIS MORNING, BUT SNOW MIXED
IN ACROSS AND NORTH OF THE SEWARD PENINSULA THIS AFTERNOON AS DEEPER
MOISTURE AND STEADY PRECIPITATION WITH THE PRIMARY DISTURBANCE MOVED
INLAND AND SHOULD BRING THE HEAVIEST INTERIOR SNOWFALL TONIGHT.
EXTENDED FORECAST DAYS 4-7
THE EXTENDED PERIOD BEGINS WITH A HIGHLY AMPLIFIED PATTERN ACROSS
NORTHEAST PACIFIC OCEAN. INTENSE RIDGING CURRENTLY ACROSS THE
ALEUTIANS SHIFTS EAST ACROSS WESTERN CANADA AHEAD OF A DEEP
SUBTROPICAL LOW. THIS CLOSED LOW IS CURRENTLY NEAR THE DATELINE AT
~30N LIFTS NORTH TOWARD THE ALASKA PENINSULA ON SATURDAY. ALREADY
HIGH PRECIPITABLE WATER VALUES ACROSS THE INTERIOR WILL BE BOLSTERED
BY AN ATMOSPHERIC RIVER. AT THIS TIME THE BEST CHANCES FOR
PRECIPITATION BETWEEN FRIDAY AND SATURDAY NIGHT IS ASSOCIATED WITH A
FRONTAL BOUNDARY POSITIONED ACROSS THE WEST COAST AND WESTERN
INTERIOR. A DISTURBANCE EMBEDDED WITHIN THE ATMOSPHERIC RIVER MAY
BRING ADDITIONAL SNOW CHANCES ACROSS THE NORTHERN INTERIOR AND
THE ARCTIC WITH WARMER AND DRIER CHINOOK FLOW PREVAILING ACROSS
THE SOUTHEASTERN INTERIOR.
COASTAL HAZARD POTENTIAL DAYS 3 AND 4...
NEAR GALE-FORCE WEST-SOUTHWESTERLY WINDS ACROSS THE NORTON SOUND
MAY PUSH WATER THROUGH CRACKS IN ICE. FLOODED SHOREFAST ICE IS
THEREFORE POSSIBLE ACROSS THE EASTERN NORTON SOUND TUESDAY NIGHT
INTO WEDNESDAY.
AFG WATCHES/WARNINGS/ADVISORIES
AK...WINTER WEATHER ADVISORY FOR AKZ834.
WINTER WEATHER ADVISORY FOR AKZ838>845.
WINTER WEATHER ADVISORY FOR AKZ847.
PK...BRISK WIND ADVISORY FOR PKZ801>805-852.
BRISK WIND ADVISORY FOR PKZ806.
BRISK WIND ADVISORY FOR PKZ812>814-858>860.
BRISK WIND ADVISORY FOR PKZ815.
BRISK WIND ADVISORY FOR PKZ816-817-851.
BRISK WIND ADVISORY FOR PKZ850-853.
BRISK WIND ADVISORY FOR PKZ854.
BRISK WIND ADVISORY FOR PKZ861.
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