733
FXAK68 PAFC 241234
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
434 AM AKDT SAT OCT 24 2026
SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 3)
DISCUSSION:
THE UPPER-LEVEL RIDGE THAT WAS IN PLACE YESTERDAY IS NOW MOVING
OFF THE EAST IN RESPONSE TO AN UPPER-LEVEL SHORTWAVE ASSOCIATED
WITH A STRONG FRONTAL SYSTEM MOVING INTO SOUTHWEST ALASKA THIS
MORNING. CLOUDS HAVE NOW MOVED ACROSS MOST OF SOUTHCENTRAL THIS
MORNING, BUT NOT BEFORE OVERNIGHT LOW TEMPERATURES FELL INTO THE
MID 20S TO LOWER 30S FOR MOST LOCATIONS AND INTO THE TEENS AND
SINGLE DIGITS IN THE COPPER RIVER BASIN.
AS OF 4 AM, PRECIPITATION IS ALREADY BEGINNING TO FILL IN FROM
KODIAK ISLAND NORTH TO SELDOVIA AND NORTHWESTERN SUSITNA VALLEY.
ANOTHER AREA OF SHOWERS SOUTH OF PRINCE WILLIAM SOUND IS ALSO
BEING PULLED NORTHWARD IN THE DEVELOPING SOUTHERLY FLOW IN THE
WAKE OF THE RIDGE. ALONG THE COAST, GAP WINDS ARE KEEPING
TEMPERATURES ABOVE FREEZING, ALLOWING FOR THE INCOMING SHOWERS TO
FALL AS RAIN. FARTHER INLAND, ANY PRECIPITATION THAT DOES DEVELOP
THIS MORNING ACROSS THE SUSITNA VALLEY WILL LIKELY FALL AS SNOW
DUE TO THE COLDER TEMPERATURES. ONE CAVEAT TO ALL THIS IS
INCREASING WARM AIR ADVECTION IN THE LOWER LEVELS OF THE
ATMOSPHERE THIS MORNING WITH A FORECASTED WARM NOSE OF AIR BETWEEN
1,500 FT AND 3,000 FT PUSHING ABOVE FREEZING ALL THE WAY INTO THE
SOUTHERN AND CENTRAL SUSITNA VALLEY. GIVEN THIS, THERE IS A
15-25% CHANCE THAT A FEW AREAS THAT TYPICALLY DO NOT SEE WINDS AND
WARMING TEMPERATURES RIGHT AWAY WITH THESE SYSTEMS (E.G. WILLOW
TO TALKEETNA) COULD SEE A BRIEF PERIOD OF VERY LIGHT FREEZING
RAIN LATER THIS MORNING AS THE STEADIER PRECIPITATION MOVES IN
BEFORE TEMPERATURES WARM UP AND CHANGE ANY SNOW OR MIXED
PRECIPITATION TO ALL RAIN.
AS THE FRONT MOVES INTO SOUTHCENTRAL, SOUTHEASTERLY GAP WINDS
WILL KICK IN, WARMING TEMPERATURES ACROSS TURNAGAIN ARM AND PARTS
OF THE MAT VALLEY. PRECIPITATION HERE WILL LIKELY BE ALL RAIN
WITH THIS SYSTEM. FARTHER NORTH ACROSS THE NORTHERN SUSITNA AND
COPPER RIVER VALLEYS TEMPERATURES WILL LIKELY (70-80%) REMAIN
BETWEEN 29 AND 34 DEGREES, ALLOWING FOR A MOSTLY SNOW EVENT WITH
SEVERAL INCHES OF ACCUMULATION. WINTER WEATHER ADVISORIES ARE OUT
FOR THESE AREAS FOR 4" TO 12" OF SNOW THROUGH SUNDAY.
A SURFACE LOW WILL THEN DEVELOP ALONG THE STALLING FRONT
SOMEWHERE NEAR THE SOUTHERN TIP OF THE KENAI PENINSULA AS ANOTHER
POTENT SHORTWAVE MOVES ACROSS THE AKPEN AND INDUCES THE SURFACE
LOW DEVELOPMENT. THE UPPER-LEVEL WAVE THEN BECOMES NEGATIVELY
TILTED BY SUNDAY AFTERNOON AS THE SURFACE LOW STRENGTHENS. THIS
WILL HELP TO SHUT OFF THE GAP WINDS ALLOW FOR STEADIER
PRECIPITATION TO FILL IN ACROSS COOK INLET AND THE SOUTHERN MAT-
SU VALLEYS BEFORE THESE FEATURES QUICKLY MOVE EAST AND THE
PRECIPITATION SHUTS OFF FROM WEST TO EAST THROUGH SUNDAY NIGHT
INTO MONDAY MORNING.
A TRANSIENT RIDGE MOVES QUICKLY THROUGH THE REGION ON MONDAY
BEFORE THE NEXT WAVE APPROACHES FROM THE WEST WITH ANOTHER ROUND
OF SNOW FOR THE NORTHERN HALF OF BOTH THE SUSITNA AND COPPER
RIVER VALLEYS FOR MONDAY.
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (DAYS
1 THROUGH 3)...
KEY MESSAGES:
* SCATTERED SHOWERS PERSIST TODAY OVER SOUTHWEST AND THE NORTHERN
ALASKA PENINSULA AS A FRONT CONTINUES TO MOVE THROUGH.
* SHOWERS AND SOUTHWESTERLY GALE-FORCE SUSTAINED WINDS (WITH
HIGHER GUSTS) MOVE THROUGH THE BERING ON SUNDAY AND REACHES THE
SOUTHWEST COAST BY SUNDAY EVENING. MINOR COASTAL FLOODING IS
POSSIBLE FOR THE KUSKOKWIM DELTA (KIPNUK, TOKSOOK BAY,
KWIGILLINGOK, AND KONGIGANAK) SUNDAY EVENING.
* ACTIVE PATTERN OVER THE BERING CONTINUES AS ANOTHER LOW CROSSES
OVER THE WESTERN ALEUTIAN CHAIN MONDAY MORNING.
DISCUSSION:
SATELLITE IMAGERY THIS MORNING SHOWS A STRONG BUT WEAKENING FRONT
ACROSS SOUTHWEST ALASKA INTO THE ALASKA PENINSULA. ALONG THE
FRONT, SHOWERS AND SOUTHERLY SMALL CRAFT TO GALE-FORCE WINDS ARE
SEEN (ESPECIALLY AT HIGHER ELEVATIONS AND IN AND AROUND BRISTOL
BAY). IMMEDIATELY WEST OF THE FRONT, CONDITIONS HAVE CLEARED FOR
MUCH OF THE EASTERN ALEUTIANS, SOUTHERN ALASKA PENINSULA AND
PLACES NORTHWARD UP TO THE WESTERN PORTIONS OF THE SOUTHWEST
COAST. EVEN FURTHER WEST, AN OCCLUDING LOW IS CURRENTLY LOCATED IN
THE NORTHWESTERN BERING. SHOWERS AND SMALL-CRAFT TO BORDERLINE
GALE-FORCE SUSTAINED WINDS ARE SEEN AROUND THE LOW THROUGH MUCH
OF THE BERING AND IN THE WESTERN ALEUTIANS.
BOTH THE FRONT AND THE LOW WILL CONTINUE TO MOVE AWAY FROM THE
REGION THROUGH THE DAY. THE FRONT CONTINUES EASTWARD AND SLOWLY
WEAKENS AS IT PUSHES INTO HIGHER PRESSURE. SHOWERS AND SOME GUSTY
WINDS WILL PERSIST THROUGH SUNDAY MORNING FOR THE NORTHERN ALASKA
PENINSULA, EASTERN BRISTOL BAY, AND UP INTO THE KUSKOKWIM VALLEY.
SOME UPPER LEVEL SHORTWAVES MOVE THROUGH SOUTHWEST ALASKA THROUGH
TOMORROW, WHICH WILL HELP PUSH THE FRONT EAST. THE LARGEST OF
THESE SHORTWAVES MOVES THROUGH SUNDAY MORNING, WHICH WILL FULLY
PUSH THE FRONT INTO SOUTHCENTRAL. MOST SHOWERS OVER INTERIOR
PORTIONS OF SOUTHWEST ALASKA LOOK TO TAPER OFF BY SUNDAY MORNING,
WITH HIGHEST CHANCES OF PRECIPITATION LINGERING ALONG THE ALASKA
RANGE. AS THE LOW CONTINUES TO OCCLUDE AND MOVE NORTHWARD, SHOWERS
AND SOUTHWESTERLY SMALL CRAFT WINDS WILL PERSIST THROUGH THE
BERING. SOME SHOWERS MAY MOVE THROUGH THE KUSKOKWIM DELTA THIS
EVENING AND PERSIST OVER THE KILBUCK MOUNTAINS THROUGH TOMORROW.
FOCUS SHIFTS WESTWARD LATER THIS WEEKEND AND INTO THE WORKWEEK AS
A SERIES OF LOWS LOOK TO TRACK THROUGH THE BERING. THE FIRST OF
THESE DEVELOPS OFF THE KAMCHATKA PENINSULA TODAY AND MOVES INTO
THE WESTERN BERING BY TOMORROW MORNING. THIS LOW CONTINUES
NORTHEAST TO THE SEWARD PENINSULA BY MONDAY MORNING BEFORE RAPIDLY
DISSIPATING. SOUTH OF THE LOW, RAIN AND SOUTHWESTERLY GALE-FORCE
WINDS ARE EXPECTED THROUGHOUT THE BERING, WITH SHOWERS AND STRONG
WINDS REACHING THE KUSKOKWIM COAST BY SUNDAY EVENING. WIND GUSTS
UP TO 55 MPH ARE POSSIBLE FROM THE KUSKOKWIM COAST UP TO BETHEL
SUNDAY EVENING INTO MONDAY MORNING. CONSIDERING THE STRENGTH AND
ORIENTATION OF THE WINDS, ANOTHER ROUND OF COASTAL FLOODING IS
POSSIBLE FOR THE KUSKOKWIM COAST SUNDAY EVENING. HIGHEST
CONFIDENCE IS FOR WATER LEVELS TO REACH UP TO 1 TO 3 ABOVE THE
NORMAL HIGH TIDE LINE. THE LOW DISSIPATES MONDAY MORNING NORTH OF
THE SEWARD PENINSULA. WITH THE WEAKENING PRESSURE GRADIENT, WINDS
SUBSIDE, BRINGING A BRIEF REPRIEVE FROM COASTAL FLOOD POTENTIAL ON
MONDAY. WIDESPREAD PRECIPITATION ACROSS SOUTHWEST ALASKA SUNDAY
NIGHT INTO MONDAY BECOMES MORE SCATTERED THROUGHOUT MONDAY MORNING
THEN TAPERS OFF MONDAY AFTERNOON. HIGHEST CHANCES FOR
PRECIPITATION TO PERSIST THROUGH MONDAY EVENING WILL BE ALONG THE
ALASKA RANGE.
THE NEXT LOW MOVES NORTH FROM THE PACIFIC AND CROSSES THE WESTERN
ALEUTIANS MONDAY MORNING, BRINGING MORE SHOWERS AND GALE TO
STORM- FORCE WINDS TO THE WESTERN BERING. THIS LOW LOOKS TO BE A
BIT STRONGER AND TRACKS FURTHER WEST COMPARED TO SUNDAY'S LOW.
BY MONDAY AFTERNOON, THE LOW BEGINS TO PUSH A FRONT EASTWARD
THROUGH THE ALEUTIANS AND BERING. SOUTHERLY GALE- FORCE WINDS AND
SHOWERS WILL BE SEEN ALONG THIS FRONT. THERE IS SOME MODEL SPREAD
WITH FRONTAL PROGRESSION GIVEN HIGH PRESSURE BUILDING TO THE
EAST. HIGHEST CONFIDENCE IN THE POSITION OF THE FRONT BY TUESDAY
MORNING IS ON A LINE BETWEEN ADAK AND NIKOLSKI UP TO BETWEEN SAINT
MATTHEW ISLAND AND NUNIVAK ISLAND. THOUGH THE HIGHEST WATER
LEVELS IN THE SHORT TERM FOR THE KUSKOKWIM COAST ARE EXPECTED ON
SUNDAY NIGHT, PROLONGED SOUTHERLY, SMALL-CRAFT FORCE WINDS AND
INCREASING HEIGHTS WITH THE TIDE CYCLE WILL MAINTAIN AT LEAST A
10% CHANCE FOR MINOR COASTAL FLOODING AT HIGH TIDE CYCLES THROUGH
AT LEAST TUESDAY.
- PA
.LONG TERM FORECAST (DAYS 4 THROUGH 7: TUESDAY THROUGH
FRIDAY)...
DISCUSSION:
THE LONG TERM FORECAST REMAINS FOCUSED ON A TRANSITION TO A MORE
UNSETTLED WEATHER PATTERN ACROSS MUCH OF ALASKA AS UPPER-LEVEL
RIDGING OVER THE GULF GRADUALLY BREAKS DOWN AND A SERIES OF TROUGH
MOVE ACROSS THE BERING SEA AND INTO MAINLAND ALASKA. MODEL
GUIDANCE REMAINS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL PATTERN
THROUGH MIDWEEK, ALTHOUGH DIFFERENCES BEGIN TO EMERGE REGARDING
THE STRENGTH AND PLACEMENT OF INDIVIDUAL UPPER-LEVEL LOWS LATER
IN THE PERIOD.
HEADING INTO TUESDAY, HIGH PRESSURE OVER THE GULF WILL CONTINUE
TO PROVIDE SOME INFLUENCE OVER SOUTHCENTRAL ALASKA, KEEPING
CONDITIONS RELATIVELY QUIET COMPARED TO AREAS FARTHER WEST.
MEANWHILE, A SERIES OF SHORTWAVES WILL CONTINUE MOVING ACROSS THE
BERING SEA AND SOUTHWEST ALASKA AS A BROADER UPPER-LEVEL TROUGH
APPROACHES FROM THE WEST. PERIODS OF PRECIPITATION AND GUSTY
WINDS WILL REMAIN POSSIBLE ACROSS THE ALEUTIANS, BERING SEA, AND
SOUTHWEST ALASKA AS THESE DISTURBANCES MOVE THROUGH THE REGION.
BY WEDNESDAY INTO THURSDAY, THE UPPER-LEVEL RIDGE OVER THE GULF
WILL CONTINUE TO WEAKEN AS TROUGHING BECOMES MORE ESTABLISHED
ACROSS WESTERN ALASKA. A MORE ORGANIZED UPPER-LEVEL LOW IS
EXPECTED TO DEVELOP AND MOVE INTO MAINLAND ALASKA, BRINGING
COLDER AIR AND INCREASING CHANCES FOR PRECIPITATION. RAIN WILL
LIKELY REMAIN THE PRIMARY PRECIPITATION TYPE ALONG PORTIONS OF THE
SOUTHWEST ALASKA COAST, WHILE COLDER TEMPERATURES INLAND MAY
SUPPORT A MIX OF RAIN AND SNOW OR ALL SNOW, PARTICULARLY ACROSS
THE KUSKOKWIM AND HIGHER ELEVATIONS. SOUTHCENTRAL ALASKA MAY ALSO
BEGIN TO SEE INCREASING PRECIPITATION CHANCES AS THE UPPER-LEVEL
PATTERN SHIFTS EASTWARD.
HEADING INTO FRIDAY AND SATURDAY, BROAD UPPER-LEVEL TROUGHING
LOOKS TO REMAIN IN PLACE ACROSS MUCH OF ALASKA, WITH ADDITIONAL
SHORTWAVES ROTATING THROUGH THE REGION. THIS WILL HELP MAINTAIN AN
UNSETTLED PATTERN, WITH PERIODS OF PRECIPITATION POSSIBLE ACROSS
SOUTHWEST AND SOUTHCENTRAL ALASKA, AS WELL AS THE BERING SEA AND
ALEUTIANS. COLDER AIR ASSOCIATED WITH THE TROUGH COULD ALLOW FOR
ADDITIONAL SNOW CHANCES ACROSS INLAND LOCATIONS, ALTHOUGH
PRECIPITATION TYPE WILL DEPEND ON THE PLACEMENT OF INDIVIDUAL
DISTURBANCES AND AVAILABLE COLD AIR.
WHILE MODEL GUIDANCE SHOWS AGREEMENT IN THE OVERALL TRANSITION
TOWARD A MORE AMPLIFIED TROUGHING PATTERN, UNCERTAINTY INCREASES
TOWARD THE END OF THE WEEK REGARDING THE TIMING, STRENGTH, AND
PLACEMENT OF INDIVIDUAL SYSTEMS. THESE DIFFERENCES WILL PLAY AN
IMPORTANT ROLE IN DETERMINING WHERE THE GREATEST PRECIPITATION AND
STRONGEST WINDS DEVELOP.
LM
AVIATION
PANC...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD,
THOUGH THERE IS A CHANCE FOR LOW VFR OR MVFR CEILINGS BY LATE IN
THE PERIOD AS RAIN MOVES TOWARD THE TERMINAL. CEILINGS WILL
CONTINUE TO LOWER THROUGH THE WITH SCATTERED SHOWERS MOVING IN BY
SATURDAY AFTERNOON. WINDS THIS MORNING WILL BE LIGHT AND VARIABLE;
HOWEVER, THE TURNAGAIN ARM WIND WILL INCREASE THIS MORNING. IF IT
BENDS INTO THE TERMINAL, MOST LIKELY BY 21Z, IT WILL RESULT IN
WIND GUSTS OF 15-25 KT AT TIMES.
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