328
FXAK69 PAFG 011439
AFDAFG
NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
639 AM AKDT TUE APR 1 2025
SYNOPSIS
A WEAKENING 980 MB LOW IS TRACKING EAST ACROSS THE HIGH ARCTIC WITH
THE ASSOCIATED FRONT DRAPED FROM NORTHWEST TO SOUTHEAST ACROSS
INTERIOR ALASKA. A VERY ANOMALOUS SUBTROPICAL RIDGE IS SHIFTING
SOUTH ALONG THE DATELINE WITH HEIGHTS AROUND 580 DAM. THE MOST
INTENSE WAVE OF SNOWFALL IS ALREADY MOVING ACROSS THE INTERIOR AND
WILL DIMINISH TODAY. A SECOND AND WEAKER WAVE IS EXPECTED TONIGHT
INTO WEDNESDAY MORNING. MIXED PRECIPITATION CONTINUES FROM THE
SEWARD PENINSULA, BUT THIS IS EXPECTED TO GRADUALLY DIMINISH TODAY
AND TRANSITION TO SNOW SHOWERS AND BLUSTERY SOUTHWEST WINDS ON
WEDNESDAY. TEMPERATURES SLOWLY RISE AS WARM AIR ADVECTION
COUNTERACTS EVAPORATIVE COOLING, BUT OVERALL TEMPERATURES STAY NEAR
OR BELOW FREEZING UNTIL THIS AFTERNOON. THEY MAY THEN STAY ABOVE
FREEZING THROUGH WEDNESDAY AFTERNOON BEFORE COOLING WEDNESDAY NIGHT
ACROSS MUCH OF THE SOUTHERN INTERIOR BELOW 1000 FEET. THIS MAY
RESULT IN SLUSHY CONDITIONS THIS AFTERNOON WITH MUCH WARMER
CONDITIONS LATE THIS WEEK AND THROUGH THE WEEKEND THAT MAY RESULT IN
A DIURNAL FREEZE-THAW CYCLE AND TREACHEROUS CONDITIONS.
KEY WEATHER MESSAGES
CENTRAL AND EASTERN INTERIOR...
- SNOW DIMINISHES THIS AFTERNOON, BUT ANOTHER ROUND OF LIGHTER SNOW
IS EXPECTED LATE TONIGHT WITH ADDITIONAL TRAVEL IMPACTS FOR THE
WEDNESDAY MORNING COMMUTE.
- BLUSTERY SOUTHWEST WINDS GUSTING UP TO 30 MPH IN THE VALLEYS AND
UP TO 40 MPH DEVELOP ALONG HIGHWAY SUMMITS TODAY RESULTING IN
BLOWING SNOW POTENTIAL, INCLUDING EAGLE SUMMIT.
- ANOTHER WAVE OF LIGHTER SNOW IS EXPECTED TONIGHT INTO WED, BUT
WARMER TEMPS APPROACHING 40F WED AFTERNOON ALLOWS FOR RAIN/SNOW MIX
OR PLAIN RAIN AT ELEVATIONS BELOW 800 FT.
- WINTER WEATHER ADVISORIES REMAIN IN EFFECT FOR MOST OF SOUTHERN
INTERIOR ALASKA (EXCEPT SE ALASKA) FOR ADDITIONAL SNOWFALL AMOUNTS
OF 3 TO 6 INCHES WITH LOCALLY HIGHER AMOUNTS UP TO 10 INCHES
POSSIBLE AT THE HIGHEST ELEVATIONS, INCLUDING THE UPPER CHENA BASIN
AND EAGLE SUMMIT.
WEST COAST AND WESTERN INTERIOR...
- SATURATED ONSHORE WINDS CONTINUE TO SUPPORT A LIGHT WINTRY MIX OF
SNOW, MIST, AND FOG ACROSS THE YK DELTA TO THE SEWARD PENINSULA
THROUGH TONIGHT.
- ADDITIONAL SNOWFALL WILL MAINLY BE IN THE 1 TO 3 INCH RANGE FOR
THE WEST COAST AND WESTERN INTERIOR, BUT LOCALLY HIGHER AMOUNTS UP
TO 5 INCHES ARE POSSIBLE AT HIGHER ELEVATIONS OF THE NULATO HILLS
BEFORE SNOW TAPERS OFF WEDNESDAY.
- SOUTHWESTERLY GALE FORCE WINDS ARE POSSIBLE TONIGHT AND WEDNESDAY
MORNING THAT COULD PUSH WATER OVER ICE, BUT BLOWING SNOW POTENTIAL
IS LIMITED BY WARM TEMPERATURES.
NORTH SLOPE AND BROOKS RANGE...
- A BRIEF ~12 HOUR PERIOD OF STRONG WEST WINDS GUSTING UP TO 40-50
MPH IS EXPECTED BETWEEN 3PM TODAY AND 3AM WED, BUT THE LACK OF
FALLING SNOW SHOULD LIMIT VISBILITY RESTRICTIONS.
FORECAST ANALYSIS AND DISCUSSION
SOUTHWEST WINDS BETWEEN A 980MB ARCTIC LOW AND A 1032 MB RIDGE OVER
THE CENTRAL ALEUTIANS IS ADVECTING A PLUME OF UNSEASONABLE MOISTURE
INTO THE INTERIOR. THE STRONGEST DISTURBANCE EMBEDDED WITHIN THIS
SOUTHWESTERLY MOISTURE PLUME IS BRINGING MODERATE TO HEAVY SNOW TO
THE EAST CENTRAL INTERIOR THIS MORNING AND A SEPARATE DISTURBANCE
BRINGS ANOTHER ROUND OF LIGHTER SNOW TONIGHT INTO WEDNESDAY.
CONTINUED WARM AIR ADVECTION AND SUBSTANTIAL DIURNAL INFLUENCES
SHOULD ALLOW PRECIPITATION TO MIX WITH OR CHANGE TO RAIN BOTH THIS
AFTERNOON AND WEDNESDAY AFTERNOON, ESPECIALLY AS PRECIPITATION
INTENSITY AND ASSOCIATED EVAPORATIVE COOLING WANES. A WINTRY MIX OF
SNOW, MIST, AND FOG CONTINUES ADJACENT TO THE NORTON SOUND THIS
MORNING, BUT SNOW HAS BEEN THE DOMINANT P-TYPE ACROSS THE INTERIOR
THOUGH SOME RAIN WAS REPORTED BETWEEN MCGRATH AND LAKE MINCHUMINA
BEFORE THEY ALSO SWITCHED TO SNOW.
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.
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.
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 PKZ812>814-858>861.
BRISK WIND ADVISORY FOR PKZ815.
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