textproduct: Juneau

SYNOPSIS

Key Messages:

- A low moves SE through the eastern gulf through Tuesday, bringing persist rain over the panhandle and scattered to isolated thunderstorms along the coast.

- Strong marine wind gusts up to 35 kts possible within N Canal to Taiya Inlet this evening.

- Ridging moves into the Gulf midweek, bringing clearing skies and warming temperatures through the end of the week.

LONG TERM.../Thursday through Sunday/

The long term forecast remains largely uneventful as an area of ridging persists over the gulf through Saturday, bringing northwesterly flow, drier conditions, and warmer temperatures through the second half of the week. The whole panhandle will see clear skies through Friday, with cloud cover moving in from the north starting Saturday. Northerly winds will increase up to 25 mph overnight Wednesday and through Thursday. Winds will decrease again overnight into Friday morning before the flow switches southerly through the afternoon as the pressure gradient turns. Through the weekend, southerly winds in Lynn Canal will increase to around 20 kts with the help of sea breezes through midday. Other communities should also feel local sea breezes increase midday. High temperatures will reach the high 60s to low 70s in the northern panhandle and into the 70s in the southern panhandle Thursday and Friday with ample clearing. Some areas in the southern panhandle are looking like they may reach the upper 70s Friday and Saturday, mainly Hyder, so will continue to watch that through the week. Models are still in disagreement going into the weekend, with the EC holding onto the ridge in the gulf and the GFS favoring an upper level shortwave making it over the ridge and into the northern panhandle midweekend. Including a chance for rainfall in the northern panhandle through Saturday evening, increasing into Sunday. Depending on how things change over the next few days, we could have a very dry or very wet weekend.

AVIATION

A low pressure system and cold front is moving through the Northern Alaska Panhandle this afternoon. This system has produced thunderstorms today, including for Yakutat, Pelican, and Sitka. Through tonight, the highest thunderstorm chances look to be along mountains, but thunderstorms are possible this evening for Yakutat, Sitka, Gustavus and Juneau.

As the system brings showers and rumbles of thunder, it is expected to bring MVFR ceilings, with IFR ceilings tonight for areas south of Fredrick Sound. For the Northern Panhandle conditions are expected to improve by the end of the TAF period. Behind the front, fog is possible tonight for Yakutat and along the Chilkat. The strongest winds today are expected for Skagway. Behind the front Tuesday, winds out of the north are expected for the Northern Panhandle and improve flight conditions to VFR. The Southern Panhandle looks to stay with ceilings AoB 2500 feet through 00Z Wednesday.

MARINE

Outer waters: Kept large portions of the ongoing forecast, as current forecast has successfully represented realty well, and is closely aligned with current thoughts going forward. The strong low pressure system driving much of the current weather and the weather through Tuesday night is expected to traverse down the gulf coast tonight. West of Prince of Wales Island, it will arrive during the morning hours of Tuesday, before moving near Haida Gwaii Tuesday night. Two convective fronts are associated with this low: the first is moving over the panhandle near Sitka at time of writing, and will continue to progress eastward over the panhandle before weakening. Thunderstorms (40-50%) are possible particularly along the gulf coast, along the windward side of mountains. Frequent lightning has been observed with these storms along with heavy rain and a small chance for stronger cells with small hail, which may reduce visibility. Still 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. Wednesday sees a ramp of northwesterlies along the outer coast, driven by rising pressure, and the strong low departing to the south.

Inside Waters: Kept large portions of the ongoing forecast, as current forecast has successfully represented realty well, and is closely aligned with current thoughts going forward. Still expecting a northerly shift beginning in Lynn Canal and Glacier Bay from an approaching cold front from the north. Expecting a slow ramp up Tuesday morning, maximizing to 25 knots with gusts up to 35kt in Lynn Canal and up to 15 knots elsewhere. As for thunderstorm development, expanded out chances for thunderstorms clear into southern Lynn and southward. Highest chances for the Icy Strait area are ongoing into the evening, with chances shifting south through the night until reaching the Clarence Strait area Tuesday morning, as the low moves south. For the central panhandle, winds overnight will transition to mainly easterly before fully committing to northerly, driven by the strong surface low moving south. Currently expecting the broad northerly trend to continue through at least Thursday.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ012-013-022-031-641>644-651-661>664- 671-672.