textproduct: Juneau

UPDATE

Updated Aviation discussion following 06z TAF issuance.

AVIATION

Much of the panhandle has seen improvement to VFR, with some remaining showers bringing intermittent lowered CIGs down to 1500 to 1000 ft. Multiple waves of showers are expected to push through from another low moving into the panhandle, bringing most of the panhandle back to MVFR down to IFR at times overnight into the morning. The chances for low-end MVFR to IFR are highest between 08z tonight and 16z in the morning, before winds picking up into the morning will help to clear some areas back up to high-end MVFR to VFR even as showers continue past 18z. Confidence remains on seeing IFR CIGs being more likely in the late night and early morning period, ahead of these winds picking up, but depending on the timing, the lower CIGs may last longer into the morning for some areas. Overall though, showers overnight with some breaks between them will make many areas see jumps from VFR down to MVFR/IFR back to VFR as the showers move through, with some lingering low clouds in areas with calm winds even during these breaks.

PREV DISCUSSION......ISSUED AT 401 PM Sun Aug 30 2026

SYNOPSIS...

Key Messages:

- A brief lull in heavier rain showers is expected Sunday evening before a stronger low moves into the Gulf, bringing another round of precipitation through Monday.

- Potential for another lull in the weather starting mid week as high pressure tries to move into the area.

SHORT TERM.../Through Tuesday night/ Cloudy day with some showers around as what is left of a low weakens west of Baranof Island. General onshore flow is the rule today for most areas east of Cape Fairweather. Which is what is responsible for the cloudy and showery weather. West of Cape Fairweather, flow is offshore and significant breaks in the clouds have been observed around Yakutat. The weakening low is not going to move much into tonight before it gets absorbed by the next low dropping down from Prince William Sound tonight.

That next low will be the main forecast driver through at least Tuesday. First that low is looking to be stronger than this weekend's system was bringing increased winds to the northern 2/3rd of the panhandle and gulf waters as it drops SE Monday, and to the southern panhandle by Tuesday. A majority of these winds are not expected to be higher than 25 kt with the highest winds likely in Lynn Canal/Skagway and over the offshore waters of the gulf on Monday. Not expecting any wind gusts on land to be any higher then 30 kt so no wind advisory conditions expected.

This low is also reinforcing the onshore flow over the panhandle and bringing some upper level vorticity into the picture (mainly closely wrapped around the low center itself). So rain will be returning to many areas for Monday and Monday night, and will linger into Tuesday for the south. Total rainfall from late Sunday night to Tuesday afternoon will range from around 1 inch to around 2.5 inches. Complicating the picture is that the low will be cold core in nature with 850 mb temps dropping to near freezing in the vicinity of the low. This combined with the vorticity is raising the potential for some thunderstorms to develop from the stronger showers over the gulf and along the outer coast when these showers encounter the higher terrain along the outer coast. We have included a rather broad area of slight change thunder for the gulf waters starting late tonight west of Icy Bay and then spreading SE through the gulf and along the outer coast through Monday. The area of possible thunder persists into Tuesday as the main low heads SE before passing to the south Tuesday night.

LONG TERM.../Wednesday through Sunday/...The long term forecast remains largely uneventful. Clearing skies will continue take over the rest of the panhandle from north to south Wednesday. The low pressure system bringing rainfall to the southern panhandle Tuesday meanders southward through Wednesday, continuing a chance of scattered showers for parts of the southern and central panhandle through the afternoon. Shower potential will diminish into Thursday as an area of ridging shifts eastward through the gulf, persisting through Saturday and bringing northwesterly flow, drier conditions, and warmer temperatures through the second half of the week. High temperatures will reach the high 60s to low 70s in the northern panhandle and the low to mid 70s in the southern panhandle Thursday and Friday with ample clearing.

Northerly winds will increase up to 25 mph through Lynn Canal and into Northern Chatham Strait overnight from Tuesday into Wednesday, decrease through the day, and increase again through Thursday morning. Winds will decrease again overnight into Friday morning before the flow switches southerly through the afternoon as the pressure gradient turns. Models are in high disagreement going into the weekend, with the EC holding onto the ridge in the gulf through the weekend and the GFS favoring an upper level shortwave making it over the ridge and into the northern panhandle Saturday. Depending on how things change over the next few days, we could have a very dry or very wet weekend.

AVIATION...

As expected, currently seeing some improvement in a few locations, but in areas like Icy Strait, conditions are struggling to reach high end MVFR. As previously stated, expecting to see a return to low MVFR and IFR tonight, as multiple shortwaves both in the northern panhandle and southern panhandle move in. Guidance continues to be somewhat heavy handed in IFR to LIFR for a longer period of time. Current TAF issuance is more confident towards some IFR CIGs earlier on in the night, due to winds not picking up as fast as previously anticipated. Expecting to see CIGs lift by 16-17z tomorrow morning as winds pick up in most areas.

Not expecting any LLWS criteria from these systems moving through tonight, but may have gusty winds associated with TAF sites from Icy Strait southward.

MARINE...

Outer waters: A developing low in the northern gulf will move along the coastline from Sunday night down to Dixon Entrance on Tuesday morning. As the low traverses south, winds will shift from generally westerly, to generally southerly, to generally northerly. Strongest wind look to be in the southwest quadrant of the low, primarily in the offshore waters in the center of the gulf. Sustained winds in this area do have the potential to reach gale force, but the most represented forecast as of now is just under gale force. Expecting a fresh jolt of westerly swell as well, primarily collected with the highest wind speeds, with westerly swell of around 7 ft increasing to 11 ft for combined wave height of 14-15 ft Monday evening into Tuesday.

Inside Waters: The low pressure expected to move along the coastline will bring widespread fresh to strong southerlies to southeasterlies for the inside waters on Monday. Pulled back on the timeline of strongest winds to the late morning to early afternoon timeframe, as the front looks slightly slower than the previous forecast. Monday night sees the low pressure move offshore from Sitka, transitioning southerly to mainly easterly winds. Going further overnight, a cold front in the wake of the low moves down from Canada, increasing northerlies to around 20 knots. Due to the lack of cold air to keep the boundary layer dense, not expecting any wind speeds above 20 knots. That being said, confidence is medium on these northerly winds, and they may be increased.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ012-013-022-031-036-642>644-651-652- 661>664-671-672.