textproduct: Juneau

SYNOPSIS

Key Messages:

- Showers tapering off in the southern panhandle, with skies clearing in the northern panhandle

- A weak front will push into the southern outer coast Sunday morning, preceding a more organized front moving into the southern and central panhandle Monday into Tuesday

- Skies expected to clear out again by Wednesday night

LONG TERM.../Monday through the work week/

The long term forecast has been adjust slightly, particularly for Monday night into Tuesday. A 500 mb low near the Aleutian Chain is expected to dig southeast into the central gulf, enhancing the >75 knot jet to the south. The area of upper level divergence is then expected to move over the southern two thirds of the panhandle by Monday night, bringing additional showers and breezy conditions. At the surface, a slightly stronger than expected, gale force system will slide southeast, with the associated front moving northwards from the south over the panhandle. Largest question for this system is how far north the moisture will move, as the parent low is dropping south. Areas from Angoon to Icy Strait and Juneau, therefore, are the most uncertain with this forecast, with the added benefit of cold temperatures and snow accumulation. Due to the negative trough axis, it is possible to have a south to north band of terrain enhanced lift over the aforementioned areas. However, with moisture being the main limiting factor, relative short duration, and a present dry layer that moisture will need to punch through, not expecting large accumulations at this time. Liquid equivalent probabilities have around a 20-40% chance for areas that could receive accumulating precipitation (mainly Juneau and Icy Strait) to exceed 0.2 inches every 6 hours, which would translate into 6 inches over a 12 hour period. Will need to monitor this situation closely going forward, but current forecast represents a more realistic forecast of around 3 inches Monday night into Tuesday for these areas. For Angoon, Tenakee Springs and south, the dominant precipitation type could be snow, but warm wet bulb surface temperatures are expected to limit any snow accumulation.

For down south, expecting largely all rain, except for possibly the upper elevations of PoW Island early on. Gales off the western coast of PoW Island is expected to translate into wind gusts for the western portion between 40-50 mph. Could see these gusts for Metlakatla and to a lesser extent Ketchikan; however, as this front is more easterly in nature, these areas could see less wind than expected.

Wednesday sees another break in precipitation, clearing skies during the day and night, and diurnal temperatures with highs in the mid 30s to low 40s and lows in the mid 20s to low 30s.

Late week sees another frontal feature move into SEAK, bringing mostly warm enough temperatures for rain throughout the panhandle at sea level, and more breezy conditions.

AVIATION.../Until 00Z Monday/

For the most part, SFC winds & LLWS across all of Southeast Alaska will be benign through the entire 24-hour TAF period. SFC winds will be a bit breezy out of the northeast or northwest for PAGY & PAHN, respectively, for this afternoon. For the northern 4/5 of the Panhandle, expect flight conditions to be in the VFR category through the full forecast timeframe. For the southern 1/5 of the Panhandle, isolated snow & rain showers are possible with a continued diminishing trend through this afternoon, bringing conditions down to the MVFR category under those. Between the showers, expect VFR conditions. From late this afternoon, onward, expect VFR flight conditions for the entirety of the southern Panhandle as well.

MARINE

Outside (Gulf and Coastal Waters): Light to gentle breezes continue across the northern Gulf waters today, with gentle to moderate westerly breezes in the southern Gulf waters. This swath of winds is expected to steadily drop southward overnight, while outflow winds out of interior passes and Cross Sound pick up in the northern gulf. Seas are expected to remain around 3 to 5 ft through Sunday with up to 2 ft of westerly swell. The next system to impact the Gulf is expected to move into the area Monday, bringing a swath of gale force winds and heightened seas of 15 to 20 ft in the areas of the strongest winds by Tuesday.

Inside (Inner Channels): Northerly outflow winds through Lynn Canal, Point Couverden, and out of Taku Inlet down northern Stephens Passage have decreased to gentle and moderate breezes through the day. These winds are expected to increase again late this evening into early Sunday morning as the gradient starts to tighten again with a few hours of fresh to strong breezes likely. Through Sunday morning, the N/S oriented outflow winds will decrease as the pressure gradient turns more E/W'ly. Winds are expected to increase up to moderate breezes through Icy Strait and out Cross Sound, as well as other typical passages that are susceptible to this direction such as out of Frederick Sound near Five Finger Lighthouse and out of Keku Strait. Seas may increase up to 5 ft where outflow winds are the strongest before dropping down to a more uniform 2 to 3 ft into Monday.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ012.