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FXAK68 PAFC 251302
AFDAFC
SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
502 AM AKDT THU JUN 25 2026
SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 THROUGH 3)
THE OVERALL FORECAST REMAINS LARGELY UNCHANGED, WITH AN UPPER
LEVEL LOW SLOW MEANDERING EASTWARD ACROSS THE GULF OF ALASKA. ITS
TROUGH EXTENDS INTO SOUTHCENTRAL, PUSHING A SERIES OF EASTERLY
SHORTWAVES ACROSS THE REGION. WARMER AIR PULLED IN FROM INTERIOR
CANADA WILL RAISE TEMPERATURES INTO THE LOW TO MID 70'S FOR
INLAND AREAS TODAY AND FRIDAY, WITH UPPER 60'S EXPECTED FOR MOST
COASTAL AREAS. COASTAL AREAS ALONG THE UPPER COOK INLET, INCLUDING
KENAI AND ANCHORAGE COULD SEE TEMPERATURES DIP INTO THE LOW 70'S
ON FRIDAY AS WARM AIR IS PULLED SOUTH ALONG THE WESTERN EDGE OF
THE TROUGH. CLEARING SKIES AND WARMER TEMPERATURES, COUPLED WITH
INCREASED INSTABILITY, WILL ALLOW FOR POTENTIAL CONVECTIVE
THUNDERSTORM DEVELOPMENT AND RAIN SHOWERS OVER THE TALKEETNA
MOUNTAINS, AS WELL AS PORTIONS OF THE ALASKA RANGE, NAMELY
MENTASTA PASS AND ISABEL PASS, WITH THUNDERSTORM CHANCES OF 10%
TO 20%. ANOTHER ROUND OF ISOLATED THUNDERSTORM POTENTIAL (10-20%
CHANCE) EXTEND INTO THE COPPER RIVER BASIN AND SUSITNA VALLEY ON
FRIDAY. CONVECTIVE POTENTIAL DECREASES OVER THE WEEKEND AS
WESTERLY WAVES FROM A LOW IN THE BERING BRING IN COOLER AIR.
KM
.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (DAYS
1 THROUGH 3: TODAY THROUGH SATURDAY)...
EXPECT GENERALLY UNSETTLED WEATHER, WITH BRISK WINDS, RAIN, AND
AREAS OF LOW CLOUDS AND FOG ACROSS THE BERING SEA, ALEUTIANS, AND
SOUTHWEST ALASKA COAST. MEANWHILE IN THE INTERIOR, AFTERNOON AND
EVENING THUNDERSTORMS WILL LIKELY CONTINUE THROUGH FRIDAY. THE
PRIMARY FORECAST CHALLENGES ARE: (A) PLACEMENT OF SHOWERS AND
THUNDERSTORMS IN THE SOUTHWEST INTERIOR, AND (B) TIMING,
PLACEMENT, AND INTENSITY OF FOG.
DIVING INTO THE DETAILS... THE UPPER LEVEL PATTERN FEATURES LOWS
IN THE BERING SEA AND GULF OF ALASKA, WHILE A RIDGE LINGERS OVER
THE Y-K DELTA. OVER THE NEXT FEW DAYS, THE BERING LOW WILL
GRADUALLY MOVE INTO SOUTHWEST ALASKA, BRINGING AN OVERALL
TRANSITION TOWARDS COOLER WEATHER AND AWAY FROM SUMMERTIME
CONVECTION. UNTIL THEN, PARTS OF SOUTHWEST ALASKA WILL LIKELY SEE
AFTERNOON AND EVENING THUNDERSTORMS THROUGH FRIDAY. FOR TODAY,
LIMITED INSTABILITY WILL LIKELY LEAD TO MUCH REDUCED THUNDERSTORM
ACTIVITY AS COMPARED TO YESTERDAY. ALTHOUGH THERE REMAINS SOME
UNCERTAINTY, GUIDANCE SEEMS TO BE COALESCING AROUND WET
THUNDERSTORMS IN KUSKOKWIM VALLEY LATE THIS AFTERNOON AND EVENING.
BY TOMORROW, GUIDANCE IS TRENDING TOWARDS MUCH MORE INTENSE
THUNDERSTORM ACTIVITY. IN ADDITION TO HIGHER INSTABILITY, AN
EASTERLY WAVE WILL LIKELY BRING WIDESPREAD RAIN SHOWERS (WITH THE
POTENTIAL FOR SCATTERED THUNDERSTORMS) ACROSS MUCH OF THE
INTERIOR.
-KC
LONG TERM FORECAST (DAYS 4 THROUGH 7: SUNDAY THROUGH WEDNESDAY)
AN UNSETTLED WEATHER PATTERN WILL PERSIST ACROSS MUCH OF SOUTHERN
ALASKA THROUGH THE EXTENDED FORECAST PERIOD AS A SERIES OF WEAK
DISTURBANCES MOVE NORTHWARD FROM THE GULF OF ALASKA WHILE BROAD
LOW PRESSURE REMAINS ESTABLISHED OVER THE BERING SEA. THIS PATTERN
WILL SUPPORT PERIODS OF SHOWERS ACROSS MUCH OF SOUTHCENTRAL ALASKA
BEGINNING SUNDAY AND CONTINUING INTO EARLY NEXT WEEK.
ON SUNDAY, INCREASING MOISTURE AND SEVERAL WEAK UPPER-LEVEL
SHORTWAVES LIFTING NORTH ACROSS THE GULF WILL PROMOTE SCATTERED TO
NUMEROUS SHOWERS ACROSS THE SOUTHCENTRAL INTERIOR, INCLUDING THE
COPPER RIVER BASIN AND SUSITNA VALLEY. MODEST DAYTIME HEATING MAY
ALLOW FOR ISOLATED THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON
AND EVENING HOURS, PARTICULARLY ACROSS THE COPPER RIVER BASIN AND
PORTIONS OF THE SUSITNA VALLEY WHERE INSTABILITY APPEARS MOST
FAVORABLE. ELSEWHERE ACROSS SOUTHCENTRAL, CLOUD COVER AND COOLER
MARINE INFLUENCES SHOULD HELP LIMIT THUNDERSTORM DEVELOPMENT.
BY MONDAY, ENERGY ASSOCIATED WITH THE BERING SEA LOW BEGINS
SHIFTING EASTWARD INTO MAINLAND ALASKA. AS A RESULT, SHOWER
ACTIVITY IS EXPECTED TO BECOME MORE WIDESPREAD ACROSS
SOUTHCENTRAL, WITH PERIODS OF RAIN DEVELOPING ACROSS PORTIONS OF
THE KENAI PENINSULA, SUSITNA VALLEY, COPPER RIVER BASIN, AND
SURROUNDING HIGHER TERRAIN. WHILE RAINFALL AMOUNTS GENERALLY LOOK
LIGHT TO MODERATE, LOCALLY HEAVIER SHOWERS WILL REMAIN POSSIBLE
BENEATH STRONGER CONVECTIVE CELLS.
SHOWERY AND UNSETTLED CONDITIONS ARE EXPECTED TO CONTINUE THROUGH
TUESDAY AS THE UPPER-LEVEL PATTERN REMAINS PROGRESSIVE AND WEAK
DISTURBANCES CONTINUE MOVING THROUGH THE REGION. TEMPERATURES
SHOULD REMAIN NEAR SEASONAL NORMALS, THOUGH PERSISTENT CLOUD
COVER AND PRECIPITATION MAY KEEP DAYTIME HIGHS SLIGHTLY COOLER IN
AREAS THAT EXPERIENCE MORE FREQUENT RAINFALL. ISOLATED
THUNDERSTORMS MAY REMAIN POSSIBLE ACROSS THE EASTERN INTERIOR
PORTIONS OF SOUTHCENTRAL, ESPECIALLY NEAR THE COPPER RIVER BASIN
DURING THE AFTERNOON AND EVENING HOURS.
BY WEDNESDAY, GUIDANCE SUGGESTS A STRONGER NORTH PACIFIC SYSTEM
MOVING INTO THE BERING SEA MAY BEGIN INCREASING SOUTHERLY FLOW
ACROSS SOUTHERN ALASKA. THIS COULD LEAD TO INCREASING MOISTURE
TRANSPORT INTO SOUTHCENTRAL AND MAINTAIN CHANCES FOR SHOWERS
ACROSS MUCH OF THE REGION. CONFIDENCE IN SPECIFIC TIMING AND
IMPACTS REMAINS LOWER THIS FAR OUT, BUT THE OVERALL SIGNAL FAVORS
CONTINUED UNSETTLED WEATHER WITH PERIODS OF RAIN, EXTENSIVE CLOUD
COVER, AND LOCALLY BREEZY CONDITIONS DEVELOPING THROUGH FAVORED
GAP WIND LOCATIONS AND ALONG PORTIONS OF THE GULF.
FATHER WEST, A STRONGER NORTH PACIFIC LOW AND ASSOCIATED FRONT
WILL BRING HAZARDOUS MARINE CONDITIONS TO THE WESTERN ALEUTIANS
AND WESTERN BERING EARLY NEXT WEEK. SUSTAINED SOUTHEASTERLY GALE-
FORCE WINDS WITH STORM-FORCE GUSTS REMAIN POSSIBLE, ACCOMPANIED BY
PERIODS OF MODERATE TO HEAVY RAIN. THESE CONDITIONS ARE EXPECTED
TO SPREAD EASTWARD THROUGH THE ALEUTIAN CHAIN, REACHING ADAK AND
ATKA MONDAY BEFORE ADVANCING TOWARD UNALASKA AND NIKOLSKI BY
TUESDAY. MARINE INTERESTS SHOULD CONTINUE MONITORING LATER
FORECASTS AS CONFIDENCE IN A PERIOD OF IMPACTFUL WINDS AND
RAINFALL REMAINS RELATIVELY HIGH.
LM
AVIATION
PANC...VFR CONDITIONS WILL MOSTLY PERSIST. THERE IS A CHANCE FOR A
LOWER CLOUD DECK TO REDEVELOP OVERNIGHT AND INTO THE MORNING
HOURS TOMORROW. SHOULD THIS HAPPEN IT COULD PUSH CEILINGS INTO THE
MVFR RANGE. ANY LOWER CEILINGS FROM THURSDAY MORNING SHOULD BURN
OFF BY LATE MORNING AS THIS IS NOT DUE TO A LARGE AREA OF STRATUS
THROUGHOUT COOK INLET, BUT RATHER FROM RESIDUAL LOW LEVEL MOISTURE
LOCALLY THAT CONDENSES AS AN INVERSION DEVELOPS. WINDS ARE
EXPECTED TO REMAIN MOSTLY FROM A WESTERLY DIRECTION AT 10 KT OR
LESS.
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