textproduct: Juneau

UPDATE

Updated aviation discussion following 18z TAF issuance.

AVIATION

VFR conditions prevail across the panhandle today, with predominantly calm winds this morning with the exception of some areas still seeing some NW-ly winds around 10 kts from the lingering pressure gradient over the area. This gradient will continue to weaken into the day, allowing for some sea breeze development in Skagway and Haines midday, as the stronger N-S gradient prior days have kept these southerly breezes from developing. Other areas that have seen see breezes develop the past few clear sky days will again see 10 to 15 kt sea breezes begin to kick up this morning with the daytime heating. Winds are expected to become calm again by tonight.

The main aviation concern will be a marine layer moving in overnight along the coastline, bringing potential for the NE Gulf coast down to Baranof Island seeing CIGs move in of 800-2000 ft between 10z and 18z. The timing of when this marine layer pushes in and the timing of the onset of MVFR to IFR conditions is still not confident at this time. The highest confidence is in PAYA and the coastline seeing these low stratus decks and low-end MVFR conditions begin after 12z, with the chance for IFR CIGs increasing later into the morning.

Whether the marine layer will push into Cross Sound far enough to impact PAGS and Icy Strait is still not fully certain depending on the direction of the onshore flow as high pressure in the Gulf moves closer. Likewise, PASI may not see the marine layer move in fully until later in the morning, if the low stratus deck sits just offshore and visible outside of Sitka Sound.

PREV DISCUSSION......ISSUED AT 527 AM Fri Sep 4 2026

SYNOPSIS...

Key Messages:

- High pressure out in the Gulf will bring warm, dry and mainly clear weather into the weekend.

- Daytime high temperatures across the southern panhandle will climb into the mid to upper 70s, with interior locations across PoW Island likely reaching 80s.

- A return to a cooler, more active weather pattern expected by the first half of next week.

SHORT TERM.../Through Saturday night/ Short range forecast is rather quiet with a ridge of high pressure anchored over the central gulf through the early weekend. This results in offshore flow, mostly clear skies, and warm temperatures through Saturday. The offshore flow is expected to be the strongest today with more high temperatures reaching into the 70s for many areas. The heat advisory remains out for Prince of Wales Island today where many areas away from the water may reach 80 this afternoon.

Change is coming though. Satellite imagery this morning shows a large area of marine layer low clouds advancing E across the central gulf. It will likely reach the outer coast from Cape Edgecombe north and west tonight bringing overcast skies and possible fog as it comes in. Overall flow will start to shift to more onshore flow across the north around that time allowing the clouds to flow into western Icy Strait and possibly Peril Strait by Saturday morning. Continued onshore flow into Saturday may not cause the clouds to retreat all that much on Saturday. They will likely persist in Cross Sound Saturday before advancing into the inner channels once more Saturday night. The increasing onshore flow also means a cooler marine air mass in the inner channels so high temperatures on Saturday are not expected to be as high as they will be on Friday even though most areas will likely still see mostly sunny skies.

Winds remain mostly light for most areas. However, afternoon sea breezes will be active which could reach 20 kt at times in places like Cross Sound, Icy Strait, and Skagway.

LONG TERM.../Sunday to Thursday/ The ridging over the eastern gulf starts to give way on Sunday along a short wave that moves across the northern gulf and central gulf coast to the Northeast gulf coast. Expect to see some light precipitation to spread in followed by a brief break late Monday to Tuesday and then another system to move in Wednesday and Thursday. Continuing precip Friday into the start of the weekend with the onshore flow over the northern portion of the gulf and into the panhandle.

Temperatures continuing to be near normal values for this time of the year. Localized winds along Lynn Canal could lead to some breezy days for Haines and Skagway.

AVIATION.../through Saturday morning/...VFR conditions are expected to prevail through the day Friday. Calm conditions will continue into the early morning as overnight winds have subsided to around 5 kts or less. With the pressure gradient over the region continuing to weaken, clear skies and daytime heating will be the main influence, driving onshore winds up to 15 kts.

Many areas were limited in fog formation overnight, despite calm winds and stable conditions, due to a drier surface layer. Marine layer formation also remained limited due to sustained 15 to 20 kt winds over the offshore waters. However, as high pressure shifts closer and coastal winds ease some, the potential for prolonged VIS/CIG flight impacts will increase. Confidence is increasing for MVFR or lower conditions developing along the NE Gulf coast and extending into the Icy Strait Corridor by early Saturday morning.

MARINE... Outer Waters: High pressure ridge dominates the gulf waters today with the main ridge axis around 145W. That ridge will slowly drift E and weaken into the weekend. Winds are generally out of the W or NW at around 15 kt or less. Seas are likewise somewhat low mostly 7 ft or less with the higher seas in the far SE part of the gulf. Little in the way of change expected through the weekend for either winds or seas even with a slightly higher swell (around 4 ft) coming in from the W over the weekend. Only other concern might be some reduction in visibility due to marine layer low clouds especially on the leading edge of the cloud shield as it moves east.

Inner Channels: Winds in the inner channels are generally light and favor a N or NW direction at the moment. Sea breezes are the main higher wind generator with areas of 15 to 20 kt potentially developing from these circulations over the next few afternoons and evenings, mainly in Icy Strait, Cross Sound, and Northern Lynn. N and W wind direction will continue to be favored over the weekend (exception will be Lynn Canal which will switch to a southerly sometime this afternoon) with speeds of 15 kt or less. Seas will continue to be of 4 ft or less for most areas through the weekend.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Heat Advisory until 7 PM AKDT this evening for AKZ328. MARINE...Small Craft Advisory for PKZ661.