972
FXAK68 PAFC 210050
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
350 PM AKST SAT DEC 20 2025
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA
(DAYS 1 THROUGH 3: TODAY THROUGH TUESDAY)...
..ACTIVE WARNINGS AND ADVISORIES
1) A HIGH WIND WARNING IS IN EFFECT FOR THE MATANUSKA VALLEY FROM
6PM THIS EVENING TO 12PM SUNDAY FOR NORTHEAST WINDS OF 30 TO 40
MPH WITH 60 TO 70 MPH WIND GUSTS.
2) A HIGH WIND WARNING IS IN EFFECT FOR VALDEZ FROM 6PM THIS
EVENING TO 12PM SUNDAY FOR NORTHEAST WINDS OF 25 TO 45 MPH WITH 60
TO 70 MPH GUSTS.
3) A HIGH WIND WARNING IS IN EFFECT FOR THOMPSON PASS FROM 6PM
THIS EVENING TO 6PM SUNDAY FOR NORTHEAST WINDS OF 40 TO 55 MPH
WITH GUSTS UP TO 80 MPH.
4) A WIND ADVISORY IS IN EFFECT FOR ANCHORAGE AND ALONG THE GLENN
HIGHWAY FROM 6PM THIS EVENING TO 12PM SUNDAY FOR NORTH WINDS OF
20 TO 30 MPH WITH GUSTS TO 40 TO 55 MPH.
***KEY MESSAGES***
-WINDS WILL INCREASE AGAIN THIS EVENING, ESPECIALLY THROUGH THE
MATANUSKA VALLEY, THOMPSON PASS, AND VALDEZ. GUSTY CONDITIONS
COULD ALSO EXPECTED TO EXTEND INTO NORTH/WEST ANCHORAGE THIS
EVENING INTO TONIGHT.
-VERY COLD TEMPERATURES WILL PERSIST THROUGH THE WEEKEND INTO
EARLY NEXT WEEK.
THE FORECAST LARGELY REMAINS ON TRACK. THE ONLY NOTABLE CHANGE IS
THAT GUSTY WINDS CAME INTO THE MATANUSKA VALLEY ABOUT 5 HOURS
AHEAD OF SCHEDULE.
GOING FORWARD THROUGH THE REST OF THE WEEKEND, THE MAIN STORY
WILL BE VERY STRONG NORTHERLY WINDS THIS AFTERNOON/EVENING. BY
THIS EVENING, A POTENT UPPER LEVEL SHORTWAVE TROUGH DRIVING SOUTH
FROM THE INTERIOR WILL MOVE OVER SOUTHCENTRAL, AND THEN CONTINUE
SOUTHWARD INTO THE GULF LATE TONIGHT. A SURGE OF RENEWED COLD AIR
ADVECTION AND STRONG NORTH TO NORTHEAST FLOW WILL MOVE IN TANDEM
WITH THIS TROUGH PASSAGE, KICK-STARTING ANOTHER BORA WIND EVENT.
FORTUNATELY, THIS WIND EVENT WILL BE MUCH SHORTER-LIVED THAN WHAT
WE'VE SEEN FROM THE PREVIOUS TWO BIGGER WIND STORMS THIS MONTH,
AND THE PEAK STRENGTH OF WINDS WILL ALSO NOT BE AS SEVERE.
THIS EVENING, WINDS WILL ALSO EXTEND SOUTH INTO NORTHERN AND
WESTERN PARTS OF ANCHORAGE. THE HIGHEST GUSTS ARE LIKELY IN THE
VICINITY OF PALMER, PERHAPS REACHING AS HIGH AS 75 MPH AT THE PEAK
DURING THE OVERNIGHT HOURS TONIGHT. GUSTS UP TO 55 MPH WILL BE
POSSIBLE ACROSS THE NORTHWEST PORTIONS OF THE ANCHORAGE AREA,
AGAIN PEAKING LATE TONIGHT. A WIND ADVISORY IS NOW IN EFFECT FOR
ANCHORAGE BEGINNING LATE THIS AFTERNOON, WHILE A HIGH WIND WARNING
REMAINS IN EFFECT FOR THE MAT VALLEY STARTING AT THE SAME TIME
LATE THIS AFTERNOON. WINDS WILL BEGIN TO DIMINISH SUNDAY MORNING,
BUT WILL REMAIN GUSTY OVER THE MAT VALLEY ALL THE WAY INTO SUNDAY
EVENING.
OUT TOWARDS VALDEZ AND THOMPSON PASS, FIERCE WINDS ARE ALSO
EXPECTED TO BEGIN WITH THE SHORTWAVE PASSAGE LATER TODAY. WIND
GUSTS UP TO 75 MPH WILL BE POSSIBLE IN VALDEZ FROM THIS EVENING
INTO SUNDAY MORNING, WHILE EVEN STRONGER GUSTS UP TO 80 MPH ARE
EXPECTED UP IN THOMPSON PASS DURING THE SAME WINDOW. THE SYNOPTIC
SUPPORT FOR STRONGER WINDS LOOKS LIKELY TO PERSIST FOR LONGER
HERE, POSSIBLY EXTENDING THE THREAT FOR HIGH WINDS ALL THE WAY
INTO SUNDAY EVENING. A HIGH WIND WARNING FOR BOTH VALDEZ AND
THOMPSON PASS REMAINS IN EFFECT STARTING LATER THIS AFTERNOON.
BY MONDAY, WINDS OVERALL WILL SETTLE DOWN ONCE AGAIN AS FLOW
RELAXES SOME AND BECOMES MORE NORTHWESTERLY. SURFACE TEMPERATURES
WILL LIKELY DIP DOWN LOWER AS WINDS SUBSIDE ACROSS INTERIOR
VALLEYS, LIKELY GOING BACK BELOW ZERO IN THE USUALLY FAVORED SPOTS
ACROSS THE MAT-SU, ANCHORAGE AND KENAI PENINSULA. FRIGIDLY COLD
TEMPERATURES AS LOW AS THE -40S WILL ALSO SPREAD BACK IN ACROSS
PARTS OF THE COPPER BASIN EARLY NEXT WEEK.
-AS/AM
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS
(DAYS 1 THROUGH 3: TODAY THROUGH MONDAY)...
HIGH PRESSURE OVER MAINLAND ALASKA CONTINUES TO PROMOTE A CLEAR,
COLD, AND INACTIVE PATTERN THROUGH THIS EVENING. THIS PATTERN
WILL BE CHALLENGED HOWEVER BY A FRONT APPROACHING THE SOUTHWEST
COASTLINE TONIGHT. THIS FRONT, PRODUCED BY A LOW PRESSURE SYSTEM
DIVING OUT OF THE CHUKCHI SEA LATE THIS AFTERNOON, WILL REACH THE
SOUTHWEST COASTLINE BY EARLY SUNDAY MORNING. LIGHT SNOW RATES AND
TOTALS OF LESS THAN 2 INCHES ARE EXPECTED TO SPREAD ACROSS NUNIVAK
ISLAND AND THE WESTERN KUSKOKWIM DELTA BY SUNDAY AFTERNOON. ONLY
MINOR ACCUMULATION IS EXPECTED EAST OF THE KUSKO RIVER BEFORE THE
FRONT SHEARS APART. A COOLING TREND THROUGH SUNDAY AFTERNOON IS
EXPECTED. THIS SYSTEM WILL BE QUICKLY FOLLOWED UP BY A MORE POTENT
TROUGH, PUSHING INTO THE COAST BY EARLY MONDAY MORNING. THIS
SYSTEM WILL BE ORGANIZED ENOUGH TO PERSIST BEYOND THE COAST AND
PUSH SNOWFALL FURTHER INLAND. SNOWFALL LINGERING AROUND SOUTHWEST
WILL RESULT IN TOTAL SNOW ACCUMULATIONS OF 2-4 INCHES ACROSS
SOUTHWEST ALASKA THROUGH TUESDAY MORNING. INLAND AREAS NEAR ANIAK
AND SLEETMUTE TO SEE SLIGHTLY LESS ACCUMULATIONS.
TEMPERATURES WILL CONTINUE TO BE COLD, WITH THE COLDEST AIR
SETTLED OVER THE LOWER KUSKOKWIM VALLEY WHERE OVERNIGHT LOW
TEMPERATURES WILL CONTINUE TO BE NEAR AND BELOW 20 DEGREES BELOW
ZERO. THE MAJORITY OF THE ALEUTIAN CHAIN WILL REMAIN UNAFFECTED BY
THE PASSAGE OF THESE TROUGHS, WITH THE RIDGE AXIS CONTINUING TO
PROMOTE INACTIVE WEATHER WITH SOUTHERLY WINDS FOR THE WESTERN
ALEUTIANS, AND NORTHWESTERLY WINDS FOR THE EASTERN ALEUTIANS
THROUGH TUESDAY.
-CL
.LONG TERM FORECAST (DAYS 4 THROUGH 7: WEDNESDAY THROUGH
SATURDAY)...
A STRONG UPPER LEVEL RIDGE WILL SLOWLY DRIFT EAST TO KEEP MUCH OF
THE AKPEN AND SOUTHERN ALASKA MAINLY CLEAR, COLD, AND DRY THROUGH
WEDNESDAY INTO THURSDAY. BY THURSDAY NIGHT INTO FRIDAY, A POTENT
SHORTWAVE FLATTENS THE RIDGE AS IT DRIVES SOUTH OUT OF THE ARCTIC
AND ACROSS THE INTERIOR BEFORE DEEPENING INTO A CLOSED LOW OVER
SOUTHERN ALASKA AND THE NORTHERN GULF BY THE WEEKEND. THIS TROUGH
WILL BRING INCREASED CHANCES FOR SNOW ACROSS SOUTHWEST ALASKA, THE
COPPER RIVER BASIN, AND MAINLY ALONG THE NORTHERN/INTERIOR SIDE
OF TERRAIN ACROSS SOUTHCENTRAL FOR MID TO LATE NEXT WEEK. AS THIS
SYSTEM PROGRESSES SOUTH INTO THE GULF, IT BRINGS A RENEWED THREAT
FOR STRONG NORTHERLY WINDS LATE NEXT WEEK ACROSS TYPICAL
LOCATIONS, INCLUDING THE MATANUSKA VALLEY, VALDEZ AREA/THOMPSON
PASS, AND ALONG THE SOUTHERN AKPEN AND GULF COAST. TEMPERATURES
REMAIN BELOW AVERAGE ACROSS SOUTHCENTRAL ALASKA, WITH THE COLDEST
AREA BEING THE COPPER RIVER BASIN, WHERE AMBIENT TEMPERATURES WILL
HOVER IN THE RANGE OF 20 TO 40 BELOW ZERO. SOUTHWEST ALASKA WILL
TREND WARMER THROUGH MIDWEEK AS RELATIVELY WARM, MOIST AIR RIDES
UP AND OVER THE RIDGE, WHILE THE WESTERN BERING AND ALEUTIAN CHAIN
REMAINS FAIRLY SHOWERY AND BREEZY AS THE RIDGE NUDGES EAST.
FOLLOWING THE PASSAGE OF THE TROUGH LATE NEXT WEEK, NORTHERLY FLOW
AND MUCH COLDER TEMPERATURES ARE REESTABLISHED ACROSS SOUTHWEST
ALASKA WHILE A STRONGER RIDGE BUILDS BACK ACROSS THE BERING SEA BY
NEXT WEEKEND.
AVIATION
PANC...VFR CONDITIONS EXPECTED TO PERSIST THROUGH THE PERIOD.
NORTHERLY WINDS WILL BEGIN TO INCREASE SAT AFTERNOON WITH
STRONGEST WIND GUSTS UP TO 45 KNOTS EXPECTED FROM ABOUT 06Z
THROUGH THE EARLY MORNING HOURS ON SUNDAY. BY 18Z SUNDAY WINDS
SHOULD BEGIN TO DECLINE.
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