textproduct: Juneau

UPDATE

PREV DISCUSSION......ISSUED AT 611 AM AKDT Tue Sep 15 2026

SYNOPSIS... Key Messages:

- Pockets of dense fog and low stratus across southern panhandle this morning. Marine layer pushing into the northern panhandle.

- Pattern change on the horizon as a weather system approaches later today, bringing a return of rain and elevated winds across the panhandle through midweek. Gales for Northern Lynn Canal.

- Multiple systems to impact the region late week into the weekend, with the potential for heavy rain, gusty winds and increasing seas.

SHORT TERM.../through Wednesday night/...High pressure over the Gulf continues to keep rather benign conditions across the panhandle this morning. The marine layer deck remains sitting along the coast with some patchy fog along parts of the central panhandle and outer coastline. Areas of fog have developed across the southern panhandle overnight and are expected to last into the morning, with some pockets of dense fog around POW, Petersburg, Wrangell and Ketchikan bringing visibility down to less than a mile at times this morning. This will begin to lift through the morning, though any clear skies are not likely to last long today as onshore flow brings in high cloud cover ahead of the upcoming system today into tonight.

No major changes have been made to the forecast for the system moving in today through tomorrow, with moderate to heavy rainfall rates along the NE Gulf coast. Still seeing the rainfall amounts begin to diminish as the shortwave pushes southward across the panhandle Wednesday. With this wave will bring some elevated winds across primarily the northern panhandle as it passes through. Southerly winds will begin to pick up through the day today for the far northern panhandle, reaching up to 30-35 mph late tonight/early Wednesday morning for Skagway, with these elevated winds in northern Lynn Canal lasting through much of the day Wednesday.

LONG TERM.../Thursday through Tuesday/...Upper level features continue to show a rather active pattern through the long range period. We start out with overall zonal W to E flow over much of the region that will gradually transition to a broad upper trough stretching from the Russian Far East to NW Canada by the weekend. The transition is set in motion by an upper low moving out of Russia late week that eventually anchors itself over SW mainland Alaska. The broad trough stays in place into early next week, but several short waves are evident rotating around the southern edge of it.

The active weather pattern is still apparent at the surface with a series of fronts expected to move through the region late week, through the weekend, and into early next week. First the low and front that is approaching on Friday that was a new feature in the guidance yesterday is still there, but details are still being worked out. Guidance has been somewhat split on whether this system will track S to N farther west and stronger or farther east and weaker. The trend so far looks to be toward the latter, but it will still be a wet (up to 1 to 2 inches of rain Fri morning to Sat morning) and breezy (winds of 15 to 25 kt for the SE gulf and inside waters) Friday regardless.

The weekend is looking interesting as well with a strong broad area of low pressure moving into the gulf from the SW and heading toward the northern gulf coast. In addition to the stronger onshore SW flow it will bring, it its wake is a shot of cooler air that will be coming in from the west. Forecast convective indices are already indicating that Sunday into Monday may be rather convective/showery in nature as the cooler air moves in and the potential is there for some thunderstorms across a large area of the gulf and outer coast at that time. I have added a broad area of slight chance of thunder at that time with the potential that areas along the outer coast could see more frequent thunderstorms from the interaction with the terrain. We will keep monitoring these systems as more details emerge.

AVIATION...Marine layer continues to persist this morning across the panhandle as ceilings and visibilities have dropped for a lot of locations. The southern panhandle continues to see the worst conditions with LIFR ceilings and visibilities. These conditions should slowly start to improve over the morning as the marine layer breaks up during daytime heating. Farther north, MVFR and VFR conditions persist but should start to improve as well. During the day today, most places should see VFR conditions as high pressure remains over the area. Winds will increase later this morning with the daytime heating before diminishing again this evening.

MARINE... Outside Waters: High pressure over the Gulf will begin to be pushed southward as the next system moves across the Gulf. Winds remain NW-ly at a gentle to moderate breeze along the coastline, with W-ly winds in the central Gulf beginning to pick up this morning to 15 to 20 kt. Winds will increase through the day Tuesday alongside a shift to a more southerly direction as the next system moves in from the west. Generally expecting winds to increase to a fresh to strong breeze, with near gale to gale force gusts, for the central and northern Gulf Tuesday afternoon through Wednesday morning. Also noting a high likelihood of increased winds near prominent capes. Wave heights of 3 to 6 ft expected Tuesday morning, building to 8 to 11 ft in the central and northern Gulf by early Wednesday morning, before diminishing through midweek, all with a more W-ly swell.

Inside Channels: Largely seeing calm conditions this morning with winds predominantly a light to gentle breeze, with the exception of some 10 to 15 kt westerly winds lasting from overnight around Sisters and Rocky Island that will begin to diminish into the morning. Winds are expected to start picking up Tuesday morning across the panhandle as the pressure gradient tightens with the incoming system. Predominately southerly winds will continue to increase Tuesday afternoon through Wednesday across the northern and central inner channels, with instead westerly winds across Cross Sound and Icy Strait. The highest of these winds will be in Lynn Canal with S winds picking up to between 25 to 35 kt tonight with gusts to 40 kt, with a period of gales expected in Northern Lynn early Wednesday morning through around midday. As this systems exits the region, winds are expected to decrease across the panhandle, but remain elevated longer over Lynn Canal with the tightened gradient staying ahead of another system late week.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Dense Fog Advisory until 10 AM AKDT this morning for AKZ326- 328>330-332. MARINE...Gale Warning for PKZ012. Small Craft Advisory for PKZ013-022-643-644-651-652-663-664-671- 672.