702
FXAK68 PAFC 151249
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
449 AM AKDT MON SEP 15 2025
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA
(DAYS 1 THROUGH 3: TODAY THROUGH WEDNESDAY NIGHT)...
THE LARGE LOW IS ENTERING THE SOUTHERN GULF OF ALASKA EARLY THIS
MORNING WITH THE OCCLUDED FRONT WRAPPED AROUND IT CREATING A FRONT
THAT IS JUST A LITTLE WAYS OFFSHORE OF THE COASTLINE FOR THE
ENTIRE GULF FROM KODIAK THROUGH SOUTHEAST ALASKA. THIS IS A
COMPLEX LOW AND THE MAIN CENTER CAN BE SEEN ON GOES-18 SATELLITE
IMAGERY ENTERING THE GULF, BUT ALSO NOTEWORTHY ON THE SATELLITE
ARE A COUPLE OF DISTINCT BENDS ALONG THE FRONT. THESE ARE AREAS
WHERE THERE ARE SECONDARY LOW CENTERS EMBEDDED ALONG THE FRONT AND
THERE ARE LIKELY LOCALIZED STRONGER WINDS AND HEAVIER RAIN NEAR
THESE AREAS. THE MAIN AREAS REFERENCED FROM EARLY MONDAY MORNING
IMAGERY ARE SOUTHEAST OF KODIAK AND SOUTH OF MIDDLETON ISLAND.
THE COMPLEX LOW CENTER WILL BEGIN TO SLOWLY FILL AND WEAKEN WHILE
THE FRONT CONTINUES TO LASH THE NORTH GULF COAST AND KODIAK
ISLAND WITH GUSTY EASTERLY TO NORTHEASTERLY WINDS ACCOMPANIED BY
MODERATE TO HEAVY RAIN AT TIMES. RAIN WILL CONTINUE ALONG THE
COAST THROUGH MUCH OF TUESDAY. KODIAK ISLAND SHOULD SEE ITS
STEADY RAIN TAPER TO SHOWERS LATE TUESDAY MORNING TO TUESDAY
AFTERNOON. AS WAS THE CASE LAST WEEK, THE HEAVIEST RAIN WILL FALL
IN WESTERN PRINCE WILLIAM SOUND WITH EAST-SOUTHEAST UPSLOPE
ENHANCEMENT. ANCHORAGE, THE WESTERN KENAI PENINSULA, AND THE MAT-
SU VALLEYS WILL REMAIN MOSTLY DRY TODAY DUE TO STRONG DOWNSLOPING
WITH EASTERLY FLOW ALOFT. NINILCHIK SOUTHWARD TO HOMER AND
SELDOVIA WILL HAVE A BETTER CHANCE FOR RAIN DUE TO BEING IN
BETTER POSITION FOR LIFT/FORCING FOR ASCENT AS WELL AS BEING
CLOSER TO THE FRONT. A FEW SHOWERS COULD MAKE IT ACROSS THE REST
OF THE WESTERN KENAI PENINSULA, ANCHORAGE, AND THE MATANUSKA
VALLEY TONIGHT INTO TUESDAY MORNING. ANY RAIN WILL NOT AMOUNT TO
MUCH OVER THOSE AREAS.
THE NEXT SYSTEM WILL THEN LIFT ACROSS THE EASTERN GULF TUESDAY
EVENING AND MAKE IT TO THE NORTHERN GULF SOMETIME ON WEDNESDAY.
THERE REMAINS A LOT OF UNCERTAINTY WITH THIS SYSTEM IN REGARDS TO
THE EXACT TRACK AND THE STRENGTH, BUT THE GFS, EC, AND CANADIAN
MODELS ALL ARE IN REASONABLY GOOD AGREEMENT WITH ITS DEVELOPMENT
AND THEN RAPID DISSIPATION WEDNESDAY OR WEDNESDAY NIGHT. THE NAM
IS SIGNIFICANTLY WEAKER AND SLOWER WITH THIS LOW'S STRENGTH AND
TIMING AND DOES NOT LOOK LIKELY TO VERIFY WELL. OVERALL THE GFS IS
PREFERRED AS IT DOES KEEP THE LOW TOGETHER UNTIL IT DISSIPATES IN
THE VICINITY OF THE COPPER RIVER DELTA ON WEDNESDAY NIGHT.
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (DAYS
1 THROUGH 3)...
THIS MORNING, SATELLITE IMAGERY REVEALS A ~984 MB LOW SITUATED
AROUND 350 MILES SOUTHEAST OF KODIAK IN THE GULF OF ALASKA. WITH A
TRANSIENT RIDGE MOVING ACROSS THE CENTRAL ALEUTIANS, A REINFORCED
NORTHERLY WIND BETWEEN THE TWO SYSTEMS HAS PICKED UP FOR THE
EASTERN MOST BERING SEA, BRISTOL BAY, THE EASTERN ALEUTIANS, AND
THE AK PEN, WITH WINDS GUSTING UP TO 25-30 KTS THROUGH FAVORED
BAYS AND PASSES. WINDS SOUTH OF THE AK PEN LOOK TO PEAK SOMETIME
THIS MORNING, WITH GALE FORCE WIND GUSTS BEING FELT OFFSHORE WEST
AND SOUTHWEST OF KODIAK ISLAND. APART FROM BREEZY CONDITIONS AND
MID LEVEL CLOUDS MOVING ACROSS SOUTHWEST ALASKA, EXPECT QUIET
WEATHER FOR THIS REGION FOR THE NEAR TO SHORT TERM.
FARTHER WEST, THE EASTERN MOST PORTION OF THE CLOUD SHIELD OF A
HIGH-END GALE FORCE LOW IS MOVING ACROSS THE WESTERN ALEUTIANS AND
POINTS EASTWARD TO AMCHITKA AND ADAK. BY MIDDAY TODAY, ITS FRONT
WITH STORM FORCE GUSTS AND A MODERATE SWATH OF RAINFALL PUSHES
ACROSS THE WESTERN ALEUTIANS. THE FRONT QUICKLY PROGRESSES FARTHER
EASTWARD LATE MONDAY WITH ITS ATTENDANT LOW STILL SPINNING JUST
NORTH OF THE WESTERN ALEUTIANS. AS THE FRONT SKIRTS FARTHER TO THE
EAST, GUIDANCE SHOWS THAT IT BEGINS TO WEAKEN TUESDAY MORNING AS
SURFACE TROUGHING BECOMES MORE ELONGATED AS UPPER LEVEL DYNAMIC
FORCING DECREASES. AS THE LOW BEGINS TO LIFT AND RETROGRADE
SLIGHTLY TO THE WEST HEADING INTO MIDDAY TUESDAY, MODELS DEPICT A
STING JET FORMING IN THE WAKE OF THE MAIN TROUGH AXIS, WHICH COULD
BRING ANOTHER SHORT LIVED PERIOD OF GALE FORCE WINDS TO THE
WESTERN ALEUTIANS.
FURTHER INTO THE SHORT TERM, THE UPPER LEVELS SHOW THE LARGE
UPPER LOW/TROUGH ACROSS THE WESTERN BERING ASSOCIATED WITH THE
SURFACE LOW DIGS AND PUSHES SOUTHWARD ACROSS THE WESTERN ALEUTIANS
AND INTO THE NORTH PACIFIC. DOWNSTREAM OVER THE CENTRAL
ALEUTIANS, A MOIST SOUTHWEST FLOW WILL BRING RAIN CHANCES INTO THE
PICTURE WEDNESDAY AFTERNOON. RAIN CHANCES WILL CONTINUE HEADING
INTO THE END OF THE WEEK AS A COMPACT LOW EMERGES FROM THE NORTH
PACIFIC AND ALIGNS ITSELF WITH UPPER LEVEL DIVERGENCE FROM THE
DIGGING TROUGH AND SUBSEQUENTLY DEEPENS. THE BERING LOW EVOLVES
MORE INTO A COMPLEX LOW AT THIS TIME AS THE COMPACT LOW MOVES
TOWARD THE AK PEN, KEEPING THE REGION UNSETTLED THROUGH THE REST
OF THE SHORT TERM.
-AM
.LONG TERM FORECAST (DAYS 4 THROUGH 7: THURSDAY THROUGH
SUNDAY)...
GENERALLY STORMY WEATHER CONTINUES IN THE EXTENDED FORECAST AS A
BROAD UPPER LEVEL LOW SLOWLY MOVES OVER THE BERING SEA AND ALASKA.
SHORTWAVE TROUGHS MOVING ALONG AND PHASING WITH THE UPPER LOW
WILL LEAD TO THE DEVELOPMENT OF ATTENDANT SURFACE LOWS, THOUGH
WHERE THESE FEATURES WILL FORM REMAINS UNCERTAIN THIS FAR IN
ADVANCE. FOR NOW, THE STORM TRACK LOOKS TO CURVE ALONG THE
ALEUTIAN ISLANDS AND UP INTO THE GULF OF ALASKA. THE STRONGEST
SIGNAL IS FOR A SURFACE LOW TO MOVE INTO THE GULF LATE NEXT WEEK,
BRINGING STRONGER WINDS AND HEAVIER RAIN ALONG THE NORTH GULF
COAST. STILL, OVERALL CONFIDENCE IS LOW. CONFIDENCE IS HIGHER
REGARDING A GENERAL TREND FOR CONTINUED RAIN ALONG THE NORTH GULF
COAST, EVEN IF DETAILS LIKE SURFACE LOW TRACK REMAIN UNCERTAIN,
DUE TO CONTINUED ONSHORE FLOW. IN ADDITION, SOUTHWESTERLY UPPER
LEVEL FLOW WILL BRING THE POTENTIAL FOR RAIN TO MOVE UP COOK
INLET AND INTO THE MAT-SU VALLEYS.
-KC
AVIATION
PANC...THE THREAT FOR AREAS OF FOG AND LOW STRATUS WILL PERSIST
FOR A FEW MORE HOURS THIS MORNING. PERIODS OF IFR CONDITIONS OR
LOWER WILL BE POSSIBLE AT TIMES IF FOG REACHES THE TERMINAL,
THOUGH ANY FOG IS LIKELY TO CLEAR OUT A FEW HOURS AFTER SUNRISE
ONCE AGAIN TODAY. OTHERWISE, VFR CONDITIONS AND NORTHERLY 5 TO 10
KT WINDS WILL PERSIST THROUGH TONIGHT. RAIN SHOWERS WILL LIKELY
MOVE BACK OVER THE TERMINAL EARLY TUESDAY MORNING, WITH SOME
SLIGHT LOWERING OF CEILINGS POSSIBLE AS RAIN ARRIVES.
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