textproduct: Juneau

SYNOPSIS

Key Messages:

- No major weather hazards are expected through Sunday with mainly clear and dry conditions, along with chilly overnight low temperatures.

- A weak disturbance will slide south through SEAK Sunday night through Monday, bringing a chance of light rain showers.

- Quiet weather returns for Tuesday with more sun and dry conditions expected. Northerly outflow winds expected to increase through the inner channels.

LONG TERM.../Wednesday through Friday/

Confidence in the long term forecast is fairly high, in that there is great agreement on a large high being situated over the Gulf of Alaska through almost the end of the workweek. This will lead to mostly light winds, with the exception of Wednesday. As a low recedes south of Haida Gwaii further towards British Columbia and a tongue of high pressure comes back south to the Gulf from south- central Alaska, gradient driven winds will be stronger, but weaken over time into Thursday for the upper inner channels, such as Lynn Canal and Stephens Passage.

The next pattern change will come with the end of the work week, as a front moves toward the area later Friday into Saturday as the high breaks down. Guidance has slowed the onset of impacts with this latter system from run-to-run. At this length of forecast, conjecturing at exact impacts is a fool's errand, but elevated winds for most of the panhandle, as well as the next bout of notable rainfall are expected. An early estimate of rain onset would be Friday PM for the northern panhandle.

AVIATION

/through Monday morning/

General VFR flight conditions prevail across the panhandle this morning under mostly clear skies. Main aviation trouble is MVFR near Yakutat, and similar to last night, localized spots along the Icy Strait corridor of intermittent IFR ceilings AoB 200ft and visbys due to passing fog. By 18z, expecting rapid improvement to mostly clear skies for majority of the terminals, outside of Yakutat who will stay predominately MVFR through the day. A weak front pushes E across the Gulf through Sunday afternoon, with likeliest chances of rain for Yakutat by 21z to 06z this evening, progressing eastward towards Sitka, Gustavus, and eventually Juneau by the end of the TAF period.

Winds remain light this morning, and that trend is expected to continue through the evening with strongest winds 10 kts or less. No LLWS concerns through the TAF period.

MARINE

Outside (Gulf and Coastal Waters): Ridging in the gulf will continue moderate to fresh northwesterly breezes through the coastal waters into Monday before a weak front moves into the panhandle, spreading the swath of winds from just along the coast to the rest of the Gulf Monday. Behind the front, high pressure will build back into the gulf and continue coastal northwesterly fresh breezes with areas of strong breezes in the southeastern gulf. 5 to 6 ft wave heights with 3 ft southwesterly swell will increase back up to 8 to 9 ft with a period of 7 to 9 seconds by Monday night before beginning to decrease again. A low marine layer around 2000 ft has been pushing into Yakutat along the coast overnight, and is expected to retreat through the morning.

Inside Waters (Inner Channels): A gulf ridge is keeping winds relatively calm Sunday, with Lynn Canal expected to flip southerly for a brief period while staying below 10 kts. Some areas of patchy fog have developed in the central panhandle, mainly along land near Tenakee, Hoonah, Angoon, and Kake. These benign inner channel winds will persist through Monday before beginning to strengthen Monday night as northerly outflow begins to develop. N/S oriented inner channels will increase to fresh to strong northerly breezes through Tuesday morning, with Lynn Canal seeing closer to near gale force sustained winds persist through the day. Currently went with low-end gale force gusts throughout the channels midday Tuesday, but guidance continues to trend stronger indicating potential for 40 kt gusts or greater in Lynn Canal during this time. 1 to 2 ft wave heights will drastically increase with these strong winds, with 4 to 6 ft expected in unsheltered locations. Winds and seas generally look to trend down going into Friday.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Dense Fog Advisory until 10 AM AKDT this morning for AKZ321-324. MARINE...None.