725
FXAK67 PAJK 301817
AFDAJK
SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
1017 AM AKDT TUE JUN 30 2026
UPDATE
FOR THE 18Z TAF ISSUANCE.
ALSO, AN SPS HAS BEEN ISSUED FOR THE JUNEAU AREA REGARDING AN
OBSERVED GLACIAL LAKE RELEASE FROM LAKE NO LAKE INTO THE TAKU
RIVER. BASED UPON BASIN ESTIMATES AND CURRENT RIVER LEVELS,
FLOODING IS NOT EXPECTED. FOR THE MOST UP TO DATE INFORMATION,
REFER TO THE LATEST SPECIAL WEATHER STATEMENT AND CHECK ON THIS
AND OTHER RIVER/LAKE INFORMATION BY FOLLOWING LINKS ON OUR WEBPAGE
AT WEATHER.GOV/JUNEAU.
SYNOPSIS
KEY MESSAGES:
- ONSHORE FLOW WILL KEEP THE POTENTIAL FOR LIGHT SHOWERS AND
DRIZZLE THE NEXT TODAY FOR THE OUTER COAST AND ICY STRAIT
CORRIDOR INCLUDING JUNEAU.
- WEAK TROUGHING WILL SLIDE THROUGH THE PANHANDLE AND BRING AN
INCREASE POTENTIAL FOR LIGHT RAIN SHOWERS FOR MIDWEEK.
- SLIGHTLY STRONGER SYSTEM TO POSSIBLY IMPACT THE SOUTHERN
PANHANDLE BY THE END OF THE WEEK, BRINGING INCREASED RAIN RATES.
SHORT TERM.../THROUGH WEDNESDAY NIGHT/
GENERALLY ZONAL FLOW
ALOFT SHIFT SOUTH WITH TROUGHING OVER THE NORTHERN GULF AND
PANHANDLE THROUGH THE SHORT TERM. ONSHORE FLOW WILL BRING A FEW
LIGHT SHOWERS OR DRIZZLE OVER NORTHERN PANHANDLE TODAY, GENERALLY
ALONG THE COAST AND INTO THE ICY STRAIT CORRIDOR. A WEAK
DISTURBANCE WITHIN THE ONSHORE FLOW IS PUSHING INTO THE NORTHEAST
GULF COAST WITH A BETTER POTENTIAL FOR SHOWER OVER YAKUTAT TODAY
SHALLOWER MARINE LAYER ACROSS THE SOUTHERN PANHANDLE EXPECTED TO
BURN OFF DURING THE DAYTIME. WEAK TROUGHING WITHIN THE ONSHORE
FLOW WILL PASS THROUGH THE PANHANDLE ON WEDNESDAY, BRINGING A
SLIGHTLY BETTER POTENTIAL FOR SHOWERS, ESPECIALLY ACROSS CENTRAL
AND SOUTHERN PANHANDLE, ALTHOUGH AND RAIN RATES SHOULD REMAIN
LIGHT. WITH THE ONSHORE FLOW AND MARINE LAYER PERSISTING, COOLER
TEMPERATURES WILL CONTINUE, WITH AFTERNOON TEMPS IN THE MID 50S TO
LOWERS 60S AND NIGHTTIME TEMPS IN THE MID 40S TO LOWER 50S.
LONG TERM.../THURSDAY THROUGH SATURDAY/
WE START THE PERIOD
OUT WITH CONTINUED GENERAL RIDGING & ONSHORE FLOW OVER THE
PANHANDLE THURSDAY MORNING. A WEAK SHORTWAVE WILL ALSO TRACK
SOUTHEASTWARD, MOVING SOUTH OF THE PANHANDLE, OVER HAIDA GWAII, ON
THURSDAY. THIS LOW WILL HAVE MINIMAL IMPACT ON SOUTHERN PANHANDLE
WEATHER. NORTHERN LYNN CANAL WILL HAVE SOUTHEASTERLY WINDS OF
AROUND 15 KT THURSDAY & FRIDAY DUE TO A TIGHTENED SOUTH TO NORTH
PRESSURE GRADIENT THAT WILL BE IN PLACE BETWEEN THE RIDGE PARKED
OVER THE EASTERN GULF & PANHANDLE & LOWER PRESSURE OVER NORTHERN
BRITISH COLUMBIA & SOUTHERN CANADIAN YUKON REGION. FOR FRIDAY, A
WEAKENING LOW WILL BEGIN ITS PUSH EASTWARD THROUGH THE SOUTHERN
GULF OF ALASKA, EVENTUALLY PUSHING THROUGH THE DIXON ENTRANCE ON
SATURDAY. THIS WILL BRING WITH IT INCREASED CHANCES FOR MORE
SUBSTANTIAL RAINFALL & SOUTHEASTERLY WINDS AROUND 15 KT FOR THE
EASTERN GULF WATERS, PARTICULARLY FOR THE SOUTHERN PANHANDLE, &
INCREASED SOUTHERLY WINDS UP TO AROUND 20 KT AROUND THE DIXON
ENTRANCE & THE SOUTHERN HALF OF CLARENCE STRAIT.
AVIATION...18Z TAFS
A WEAKENED AREA OF HIGH PRESSURE IN THE GULF OF
ALASKA HAS BROUGHT A SLIGHTLY WEAKER MARINE LAYER TUESDAY
MORNING INTO THE NORTHEAST COAST AND NORTHERN PANHANDLE. STILL,
THE MARINE LAYER HAS BROUGHT CEILINGS AS LOW AS 800 FEET AT TIMES
AND IFR VISIBILITIES TO YAKUTAT, WITH SLIGHT IMPROVEMENT AS OF
THIS DISCUSSION. THE MARINE LAYER ALSO PUSHED INTO ICY STRAIT AND
MADE IT OVER TO GUSTAVUS, BUT HAS ALREADY BEGUN TO RETREAT BACK
TOWARDS CROSS SOUND WHERE FAA WEATHERCAMS CONFIRM CIGS STILL AOB
1500 FT. THESE ARE EXPECTED TO GRADUALLY LIFT WITH DAYTIME
HEATING. WITH ONSHORE FLOW, SHOWERS ACROSS THE CENTRAL AND
NORTHERN PANHANDLE (E.G. GUSTAVUS AND JUNEAU) COULD BRING SOME
CEILINGS AROUND 2500 FEET. CONFIDENCE IN THESE SHOWERS DROPPING
CONDITIONS IS LOW, BUT CERTAINLY A POSSIBILITY AFTER 15Z TUESDAY.
AS THE RIDGE CONTINUES TO WEAKEN IN THE GULF OF ALASKA AND A
SHORTWAVE DISTURBANCE MOVES ALONG THE NORTHERN EDGE, THE MARINE
LAYER AFTER 06Z WEDNESDAY IS ALSO EXPECTED TO BE WEAKER. WITH
BREAKS IN THE CLOUDS, THERE MAY BE SOME FOG BY EARLY WEDNESDAY
MORNING, BUT CONFIDENCE STILL REMAINS LOW ENOUGH TO NOT INCLUDE
WITH THIS TAF ISSUANCE. FOG FORMATION WILL LARGELY DEPEND ON HOW
MUCH CLEARING OCCURS THIS EVENING.
MARINE
OUTSIDE (GULF AND COASTAL WATERS): A RIDGE OF HIGH PRESSURE IN
THE GULF OF ALASKA IS CONTINUING TO WEAKEN, SO WINDS AND WAVES ARE
EXPECTED TO CONTINUE DISSIPATING TUESDAY. WINDS THAT HAVE BEEN
NORTHWESTERLY IN THE SOUTHERN GULF WILL BECOME MORE WESTERLY AND
WEAKEN AS A RESULT OF THE WEAKENING HIGH PRESSURE. 15-20 KT WINDS
AND SEAS UP TO 6 FEET ARE STILL EXPECTED IN THE GULF TUESDAY, BUT
EXPECTED TO BE LOWER WEDNESDAY AND THURSDAY.
INSIDE (INNER CHANNELS): AS THE RIDGE OF HIGH PRESSURE CONTINUES
TO WEAKEN, EXPECT THE STRONGEST WINDS IN LYNN CANAL, CROSS SOUND,
AND NEAR CAPE DECISION TO WEAKEN THROUGH THE DAY TUESDAY.
WEDNESDAY INTO THURSDAY, A WEAKLY ORGANIZED LOW PRESSURE SYSTEM
LOOKS TO APPROACH HAIDA GWAII. THIS MAY BRING SOME 10-15 KT
EASTERLY WINDS TO DIXON ENTRANCE, BUT CONFIDENCE IN THIS OCCURRING
IS FAIRLY LOW AT THIS TIME. IF THE LOW PRESSURE SYSTEM TRACKS
SLIGHTLY FURTHER NORTH, IT MAY IMPACT OUR INNER CHANNELS, BUT EVEN
IF IT DOES WINDS WILL LIKELY REMAIN UNDER 15 KTS AREA WIDE.
AJK WATCHES/WARNINGS/ADVISORIES
PUBLIC...NONE.
MARINE...NONE.
SHORT TERM...DS
LONG TERM...JLC
AVIATION...STJ
MARINE...MUSALL
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