006
FXAK68 PAFC 270152
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
452 PM AKST MON JAN 26 2026
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 3:
TONIGHT THROUGH THURSDAY)...
KEY MESSAGES:
- WIDESPREAD SNOWFALL IS STILL EXPECTED ACROSS SOUTHCENTRAL
THROUGH TUESDAY.
- CONFIDENCE HAS INCREASES FOR HIGHER SNOWFALL AMOUNTS AND RATES
ACROSS MUCH OF THE KENAI PENINSULA, ANCHORAGE AND MAT-SU VALLEYS
TONIGHT THROUGH TUESDAY NIGHT.
- WINTER WEATHER ADVISORIES HAVE BEEN EXPANDED TO COVER NEARLY ALL
OF THE MAINLAND PORTIONS OF SOUTHCENTRAL THROUGH TUESDAY DUE TO
THE COMBINATION OF HEAVY SNOWFALL RATES AND AMOUNTS EXPECTED
THROUGH TUESDAY NIGHT.
A COMPLEX SNOW EVENT CONTINUES TO EVOLVE AND SHIFT ACROSS PARTS OF
SOUTHCENTRAL THIS AFTERNOON. AN ELONGATED UPPER LEVEL TROUGH AXIS
NOW EXTENDS ALL THE WAY FROM THE CENTRAL YUKON DOWN INTO PARTS OF
SOUTHWEST ALASKA. THIS FEATURE IS BECOMING INCREASINGLY STRETCHED
OUT AS IT INTERACTS WITH A POTENT POLAR LOW RETROGRADING WEST
ACROSS THE INTERIOR AND NORTH SLOPE. FARTHER SOUTH, AN INVERTED
SURFACE TROUGH NOW EXTENDS NORTH ACROSS MUCH OF THE GULF. A
CONTINUOUS FEED OF MOISTURE IS BEING PULLED NORTHEAST FROM THE
SURFACE TROUGH OVER THE GULF AS A BELT OF SOUTHWEST FLOW
CONTINUES TO MOVE OVER SOUTHCENTRAL ON THE SOUTHEAST SIDE OF THE
MAIN UPPER TROUGH. THERE IS ALSO NOW A FAIRLY STRONG TEMPERATURE
GRADIENT IN PLACE FROM SOUTH TO NORTH, WITH THE COLDEST AIR
FILTERING INTO THE COPPER BASIN AND SUSITNA VALLEY. THIS GRADIENT
COUPLED WITH THE SOUTHWESTERLY FLOW ALOFT IS CAUSING AIR ALOFT TO
GLIDE UPWARDS (ISENTROPIC LIFT) AS IT STREAMS NORTHEAST AND LIFTS
OVER THE TOP OF THE COLDER AIR MASS IN PLACE TO THE NORTH. IN
SHORT, THIS IS CAUSING THE WIDESPREAD SNOWFALL ACROSS MUCH OF
PRINCE WILLIAM SOUND AND THE COPPER RIVER BASIN REGIONS TODAY. A
NEARLY STATIONARY, SMALLER BAND HAS ALSO SET UP ACROSS PARTS OF
ANCHORAGE AND THE MAT VALLEY, WHERE UP TO A FEW NEW INCHES OF
SNOWFALL HAVE ALREADY BEEN OBSERVED TODAY.
LOOKING TO THE NEAR-TERM OUTLOOK, FORECAST CONFIDENCE FOR A MORE
NOTABLE SNOWFALL EVENT EXTENDING INTO TUESDAY HAS IMPROVED
MARKEDLY COMPARED TO YESTERDAY. FROM TONIGHT INTO TUESDAY, THE
UPPER LEVEL TROUGH IN PLACE NEAR THE ALASKA RANGE WILL BE SHEARED
APART BY THE POLAR LOW AS IT HEADS TOWARD THE BERING SEA.
MEANWHILE, AN OCCLUDED FRONT ASSOCIATED WITH A LOW DRIFTING OVER
THE NORTHEAST PACIFIC WILL BEND NORTHWEST ACROSS THE GULF AS A
WEAK SURFACE LOW FORMS ALONG THE BOUNDARY AND MOVES TOWARDS THE
SOUTHERN TIP OF THE KENAI PENINSULA. THIS WILL EFFECTIVELY SHIFT
THE MAIN BAND OF SNOW OVER PRINCE WILLIAM SOUND AND THE COPPER
BASIN WEST INTO THE KENAI PENINSULA, ANCHORAGE AND MAT-SU VALLEYS.
A BURST OF VERY INTENSE SNOWFALL RATES OF AN INCH PER HOUR OR
GREATER IS NOW EXPECTED FOR SEVERAL HOURS ON TUESDAY ACROSS MUCH
OF THE WESTERN HALF OF SOUTHCENTRAL. HEAVY SNOW WILL FIRST
PROGRESS ACROSS PARTS OF THE KENAI PENINSULA IN THE MORNING, THEN
SPREAD INTO ANCHORAGE AND THE MAT-SU REGIONS BY THE AFTERNOON.
FORECAST SNOWFALL TOTALS HAVE BEEN UPPED ONCE MORE ACROSS THIS
REGION THROUGH TUESDAY EVENING, WITH ADDITIONAL AMOUNTS THROUGH
TUESDAY NIGHT NOW RANGING FROM 4 TO 12 INCHES. HEAVIER AMOUNTS OF
UP TO 2 FEET IN TOTAL ARE ALSO EXPECTED FOR VALDEZ AND THOMPSON
PASS THROUGH LATE TUESDAY. STORM TOTAL AMOUNTS OF UP TO 18 INCHES
REMAIN ON TRACK FOR THE COPPER BASIN. SNOW WILL FINALLY COME TO AN
END FROM EAST TO WEST ON TUESDAY NIGHT.
FOR WEDNESDAY AND BEYOND, A WARMER AND STILL UNSETTLED PATTERN
WILL CONTINUE FOR MUCH OF SOUTHCENTRAL. A POTENT TROUGH WILL MOVE
ACROSS THE GULF FROM EAST TO WEST ON WEDNESDAY, SENDING A CORRIDOR
OF GALE FORCE WINDS ACROSS THE NORTHERN GULF AND ANOTHER ROUND OF
PRECIPITATION INTO PRINCE WILLIAM SOUND AND THE EASTERN KENAI
PENINSULA. THIS FEATURE WILL ALSO BRING A SURGE OF WARMER AIR IN
FROM THE SOUTHEAST, CHANGING SNOW OVER TO RAIN NEAR SEA LEVEL
ALONG THE GULF COAST. FARTHER INLAND, TEMPERATURES AT THE SURFACE
WILL REMAIN BELOW FREEZING AT GROUND LEVEL. WHILE LITTLE
PRECIPITATION IS EXPECTED TO MAKE IT PAST THE COASTAL MOUNTAINS,
ANYTHING THAT DOES SPILL OVER INTO THE MAT VALLEY, ANCHORAGE OR
WESTERN KENAI PENINSULA COULD FALL AS FREEZING RAIN OR SLEET DUE
TO THE WARM INTRUSION ALOFT. BY THURSDAY, A GALE FORCE LOW WILL
MOVE INTO THE GULF, EXTENDING A PERIOD OF GUSTY WINDS AND ROUGH
SEAS ALONG WITH PERIODS OF RAIN/SNOW ALONG THE GULF COAST.
-AS
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS
(DAYS 1 THROUGH 3: THIS AFTERNOON THROUGH THURSDAY EVENING)...
A COLD UPPER-LEVEL LOW CONTINUES TO ADVANCE ACROSS SOUTHWEST
ALASKA THE REST OF TODAY THROUGH WEDNESDAY. THIS FEATURE WILL
BRING A BLAST OF ARCTIC AIR OVER THE SOUTHWESTERN MAINLAND THROUGH
WEDNESDAY INTO THURSDAY MORNING. WITH THIS, A COLD WEATHER
ADVISORY REMAINS IN EFFECT FROM 3 AM AKST TUESDAY MORNING THROUGH
9 AM AKST THURSDAY FOR INTERIOR KUSKOKWIM DELTA AND LOWER
KUSKOKWIM VALLEY. WIND CHILLS COULD REACH AS LOW AS 40 DEGREES
BELOW ZERO FOR THE AFOREMENTIONED AREAS. ELSEWHERE ACROSS
SOUTHWESTERN ALASKA, AS THE UPPER-LOW DISCUSSED ABOVE MOVES
WESTWARD OVER THE KUSKOKWIM DELTA COAST WEDNESDAY, SOUTHWESTERLY
FLOW WILL BE INTRODUCED ACROSS MUCH OF THE AREA. A BAND OF
PRECIPITATION IN THE FORM OF SNOW IS LIKELY TO DEVELOP ALONG THE
WESTERN ALASKA RANGE AND MOVE WESTWARD TO THE KUSKOKWIM VALLEY
THROUGH WEDNESDAY AFTERNOON AS IT WEAKENS. A COUPLE INCHES OF
LIGHT SNOW IS PROBABLE WITH THIS FEATURE FROM SLEETMUTE TO KING
SALMON WESTWARD TO THE WESTERN ALASKA RANGE THROUGH WEDNESDAY
AFTERNOON. LIGHT SNOW MAY EVEN MAKE IT AS FAR WEST AS ANIAK TO NEW
STUYAHOK WEDNESDAY NIGHT, BUT ACCUMULATIONS WILL BE VERY LITTLE.
OUT WEST, A NORTH PACIFIC LOW SENDS ITS FRONT INTO THE WESTERN
ALEUTIANS THROUGH THE REST OF TODAY INTO TONIGHT. THE RESULT WILL
BE GUSTY EASTERLY WINDS AND RAIN INTO SHEMYA THROUGH TUESDAY
AFTERNOON. COLD AIR WORKS IN STARTING THEN AS PRECIPITATION
CHANGES FROM RAIN TO RAIN/SNOW MIX AND EVEN ALL SNOW LATE TUESDAY
AFTERNOON INTO TUESDAY EVENING BEFORE PRECIPITATION ASSOCIATED
WITH THE FRONT TAPERS OFF. HOWEVER, SNOW WILL BE SHOWERY AS COLD
AIR WORKS IN ALOFT FROM THE NORTH TUESDAY AFTERNOON THROUGH MOST
OF THURSDAY. THERE COULD BE INSTANCES OF BLOWING SNOW WITH SOME
REDUCED VISIBILITY AS SHOWERS PASS OVERHEAD ALONG THE WESTERN AND
CENTRAL ALEUTIAN CHAIN WEDNESDAY INTO THURSDAY. HOWEVER, THE
PRIBILOF ISLANDS, ESPECIALLY SAINT PAUL ISLAND, HAVE THE BEST
CHANCE FOR SEEING REDUCED VISIBILITY IN ASSOCIATION WITH THE COLD
AIR ADVECTION FROM THE NORTH AND MORE PERSISTENT SNOW SHOWERS
DEVELOPING OFF THE ICE EDGE TO THE NORTHEAST OF THE ISLAND. THE
TIME WINDOW WHERE THE PRIBILOFS COULD SEE LOW VISIBILITY, POSSIBLY
DOWN TO A MILE OR LESS AT TIMES, IS TUESDAY NIGHT THROUGH
WEDNESDAY MORNING WHEN THE NORTHERLY WINDS AND MOISTURE ARE MOST
SYNCED UP WITH EACH OTHER. THE OTHER THING TO NOTE WITH THIS COLD
AIRMASS MOVING OVER THE BERING WILL BE HEAVY TO EXTREME FREEZING
SPRAY ACROSS THE EASTERN AND NORTH-CENTRAL BERING SEA TONIGHT
THROUGH WEDNESDAY MORNING. SNOW SHOWER ACTIVITY WILL CONTINUE
ACROSS THE BERING SEA, ALEUTIAN CHAIN, AND SOUTHERN ALASKA
PENINSULA WEDNESDAY AND THURSDAY AS ADDITIONAL SHORTWAVES ROTATE
AROUND THE BROAD UPPER LOW IN THE BERING.
LONG TERM FORECAST (DAYS 4 THROUGH 7: FRIDAY THROUGH MONDAY)
THE LONG TERM FORECAST FOR BOTH SOUTHCENTRAL AND SOUTHWEST ALASKA IS
CHARACTERIZED BY AN ACTIVE PATTERN. MANY UPPER LEVEL FEATURES
WILL MAKE THEIR WAY INTO ALASKA FROM THE NORTH PACIFIC, WHICH WILL
BRING A MIX OF WEATHER FROM SNOW, RAIN, AND WINDS.
FOR SOUTHCENTRAL, THESE UPPER LEVEL FEATURES WILL STREAM INTO THE
GULF OF ALASKA THROUGH THE WEEKEND. THE GULF COAST IS LIKELY TO
SEE PERIODS OF PRECIPITATION AS THESE FEATURES PUSH INLAND. DUE TO
A WARMER AIR MASS FROM SOUTHERLY FLOW, RAIN OR A RAIN/SNOW MIX IS
THE LIKELY PRECIPITATION TYPE FOR THESE WAVES. ANY PRECIPITATION
THAT MAKES IT FURTHER INLAND WILL LIKELY BE SNOW. A LARGER LOW
LOOKS TO MOVE INTO THE GULF OF ALASKA ON SUNDAY, LIKELY BRINGING
GUSTY WINDS AND PRECIPITATION TO THE GULF COAST AND KODIAK ISLAND.
SOUTHWEST ALASKA WILL BE A LITTLE DIFFERENT. COLD AIR ADVECTION
DUE TO NORTHEASTERLY FLOW WILL CONTINUE THROUGH THE WEEKEND,
INTERACTING WITH WEAK FEATURES TO PRODUCE AREAS OF SNOWFALL IN THE
BERING AND THE SOUTHWEST MAINLAND THROUGH THE WEEKEND.FOR SNOW
SHOWERS IN THE BERING AND MORE CONSTANT SNOW IN THE EASTERN
ALEUTIANS. UNCERTAINTY WITH THE PATTERN ARISES ON MONDAY WITH THE
LARGE LOW IN THE GULF OF ALASKA POTENTIALLY SENDING SHORTWAVES TO
WESTERN ALASKA AND ADVECTING WARMER AIR. THIS COULD CAUSE A MIX OF
RAIN AND SNOW FOR THE ALEUTIANS BY MONDAY.
-JAR
AVIATION
PANC...PERIODS OF LIGHT SNOW, MVFR CIGS, AND LIGHT NORTHERLY WINDS
WILL PERSIST INTO THE EVENING HOURS. THERE MAY ALSO BE PERIODS OF
VERY LIGHT FREEZING DRIZZLE TONIGHT IF THE SNOW TAPERS OFF
COMPLETELY; HOWEVER, THIS SCENARIO IS LOW CONFIDENCE.
STEADIER SNOW WILL RETURN BY EARLY TUESDAY MORNING WITH CIGS/VSBY
DROPPING BACK TO IFR. THERE MAY BE A BRIEF LULL IN THE HEAVIER
SNOW LATE TUESDAY MORNING, ALLOWING FOR MVFR VIS/CIGS FOR A TIME.
HEAVIER SNOW, HOWEVER, IS EXPECTED TO RETURN BY MID-TO-LATE
TUESDAY AFTERNOON WITH VIS/CIGS LOWERING BACK TO IFR OR LIFR.
-TM
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