textproduct: Juneau

AVIATION...06z TAFs

Primarily VFR conditions continue at this time with local sea breezes quickly coming to an end. A few rain showers developed near Mosquito Lake and Skagway earlier this evening, but the most organized convection and lightning remained just outside the vicinity. A few additional showers cannot be ruled out in these areas over the next few hours. As surface high pressure remains over the central Gulf, along with an upper level low, we expect a lowering of ceilings to MVFR. Although, some mid and high level clouds across the northern and central panhandle may reduce or slow the formation of low clouds overnight. Pockets of IFR will be associated with the marine layer along the outer coast sites and PAKW. Conditions will again slowly improve across the region beginning around 18Z.

PREV DISCUSSION...ISSUED AT 241 PM AKDT Sun Aug 9 2026

SYNOPSIS...

Key Messages:

-Suicide Basin glacier dammed lake continues to fill. At this time, it is expected to be full sometime August 11th or 12th. In the past, it has taken up to 6 days for the main flooding event to start after the basin is full. Visit weather.gov/ajk/suicidebasin for more information.

-Some areas of clouds and a gradual warming trend expected through the week for the panhandle.

SHORT TERM...Relatively quiet weather continues. General flow at mid and upper levels has turned to a mostly offshore N to NE direction while low level flow is more NW or W. As a result most of the panhandle is seeing more and larger holes in the cloud cover this afternoon. The most cloud cover is still over the Juneau and Icy Strait area where some mid level convergence is keeping mid level clouds around.

Through the early part of the week, areas of clouds will stick around but substantial holes in that cloud cover will still develop due to overall light offshore flow. Some marine layer low clouds will also plague the outer coast late at night and in the mornings with some possible fog at times. The light offshore flow will also continue to bring in a slightly warmer air mass. 850 mb temperatures will be slightly warming through the next few days from around 6c today to around 8c by Tuesday. This will result in afternoon high temperatures showing a gradual warming trend with upper 60s and low 70s starting to become more common by Tuesday especially in areas that see more sun. Sea breezes will also increase with the increased afternoon heating. Winds are likely to top out at around 15 to 20 kt at most in the afternoons and evening.

One of the other question marks is the potential for any showers or thunderstorms to move into the northern panhandle from Canada this evening and Monday afternoon. Satellite imagery and lightning detection today have shown a few storms developing in the Southern Yukon as of 1pm. Nothing has come close to the Haines Customs or White Pass area yet, but the steering flow is still out of the north so will direct any storms in the southern Yukon to the south. Higher pops and a slight chance of thunderstorms remain in the forecast around White Pass and Haines Customs for this evening and Monday afternoon as convective indices remain good for both time periods.

LONG TERM...Wednesday, a closed low south of the Aleutian chain will reach full maturity, beginning to decay as it lifts north. Three primary features of interest as this system moves into the Gulf are: strength of the accompanying surface low, clear/warm over the Panhandle for the mid to end of the week, and moisture transport into the region by the weekend. Touching on the low first, ensembles show agreement that this system will make landfall along the AK Peninsula, with southerlies building in the central Gulf; winds remain below gale force. Our stubborn high over the eastern Gulf cedes territory, making a slight retreat into the Panhandle, with north-westerlies still impacting much of the coastal waters. Overall, little concern for major marine impacts with continued focus for northwest winds of moderate to fresh breezes along the Alexander Archipelago and sea breezes thru the inside.

As this high shifts into the Panhandle Thursday, warm and dry once again becomes the theme. Digging into the 850mb temps, the LREF shows a left-skewed distribution based around 7C to 15C, with the mode around 13C, translating to 75F to 85F surface temps, about 10F above normal for this time of year. The Extreme Forecast Index shines more light into this, with agreement in abnormal warmth increasing its footprint over the Panhandle into the end of this week. A note, its not just about the afternoon high temperatures, nightly low temperatures also likely remain about 10F above normal for most of the region.

Moving onto moisture, by the end of the weekend this pattern will begin to break down the dominant high, or at a minimum, push the ridge further east, with southwesterlies picking up on some equatorial moisture and funneling it into the Gulf. A few ensemble outliers want to bring a quick hit of moderate AR conditions; however, overall modest Integrated Vapor Transport values suggest just an increase in clouds, and perhaps some light rain, by the end of the weekend.

Similar to previous days, winds of sustained 10 to 15 kts will continue through this afternoon, with the highest chance of seeing any gusts reaching 20 kts being in the vicinity of Taiya Inlet. No LLWS concerns through the TAF period.

MARINE... Outside: A 1023mb high pressure remains stationary over the central Gulf into early next week, keeping generally overcast skies with light and variable winds along in the outer waters. Wave heights remain largely benign through the early week, around 4ft or less along the coast with a persistent southerly swell of 2ft or less. Accompanying this high pressure is broad westerly to northwesterly winds in the NE gulf coast down to Dixon Entrance around 10 to 15 kts or less, with the strongest winds expected in the vicinity of Cape Spencer and Cape Decision, particularly by the afternoon hours. Main marine concern for outer and coastal waters will be nightly return of marine layer, dropping visibilities potentially as low as one quarter mile each morning.

Inside: Conditions across the inside waters remain relatively benign this afternoon with only a few areas seeing winds above 10 kt, namely near ocean entrances as well as localized sea breezes. This pattern of relatively benign conditions with marine layer influence and patchy fog in the morning giving way to increasing winds and sea breezes by the afternoon will hold true through at least midweek. Wave heights remain 4 feet or less through early week as well with no significant systems to break down the influence of high pressure out in the gulf.

HYDROLOGY...Suicide basin continues to fill. With the cloudy and somewhat cool weather we have had over the weekend as well as the calving event on Friday night, we have moved the expected most likely date for a full basin to be August 11th-12th. The overflow channel is still around 1350 ft and we still expect the release to start up to 6 days after the basin has reached full status.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...None.