textproduct: Juneau

SYNOPSIS

Key Messages:

- High pressure out in the Gulf will shift east through the weekend, with a return of cooler onshore marine air.

- Seasonable temperatures this weekend across the north with highs in the in upper 50s to low 60s. Across the south, still mild for Saturday with highs in the mid 60s to mid 70s, then trending a cooler on Sunday with highs generally in the 60s.

- A return to a cooler, more active weather pattern for next week with multiple fronts pushing through southeast Alaska.

LONG TERM

/ Monday to Friday / A short wave moves to the SE AK area with a frontal band moving to the northeast gulf coast and then the panhandle through Monday and Tuesday. With an upper level high over the central pacific the flow pattern weather is looking more zonal from the just south of the Aleutians to the northern panhandle for the later half of the week. So expect the continued onshore flow to maintain the rain anticipated across the region. 24 hour rain totals in the 3/4 inch to 1.5 inch range, and models beginning to suggest a wave a bit further south with amounts focused over the southern third of the panhandle, for the Thursday to Friday timeframe.

AVIATION...Through 06Z Sunday

A ridge of high pressure in the Gulf of Alaska has kept flight conditions VFR across Southeast Alaska. Marine layer clouds associated with the ridge are expected to move eastward tonight, and bring MVFR/IFR ceilings and visibilities to Yakutat, Sitka, and Gustavus. There is uncertainty with how far inland these marine layer clouds will make it, though. With how dry the air mass in place is, fog from radiational cooling is generally not expected, but cannot be ruled out for Juneau.

A frontal band currently near Kodiak Island will continue moving the ridge eastward. This means that marine layer clouds are expected to keep MVFR ceilings for Yakutat, Sitka, and Gustavus through the end of the TAF period. As the ridge in the Gulf moves eastward, ceilings are expected to begin lowering for Juneau by 06Z Sunday. For the Southern Panhandle, the marine layer clouds are not expected to expand southeastward until after the TAF period ends.

MARINE

Inside (Inner Channels): Winds across the inside channels remain on the lighter side below 15 kts. Wind directions remain mainly northwesterly, but northern areas, through Lynn Canal, are starting to see southerly winds develop. Southerly winds will continue for that area as high pressure remains over the gulf. The main impact for the inside waters is the continued potential for increased winds due to sea breezes. These sea breezes are most likely to develop over late morning into afternoon hours. Any sea breeze that develops can bring gusty conditions. Similar conditions as what is mentioned above, will continue through the weekend as high pressure remains over the gulf. There is a chance for the marine layer, that is observed over the gulf via satellite, to continue to move eastward and reach the gulf coast. This marine layer can lower ceilings and reduce visibilities. If the marine layer reaches the coast, it is most likely to impact Yakutat Bay, Cross Sound, and Sitka Sound. It could move slightly more easterly each day. These conditions will continue until the next low pressure system reaches SE AK by late Sunday into Monday.

Outside (Gulf and Coastal Waters): A ridge of higher pressure remains over the gulf continuing to allow for predominately westerly and northwesterly winds across the gulf. These winds mainly remain at or below 15 kts for a majority of the gulf. An exception to this is the far southeastern gulf, along the coast, where increased winds near 20 kts and seas of 6 to 8 ft will continue through Saturday. On Sunday, those winds and seas are anticipated to subside and diminish. Then winds will remain on the lighter side until the next low pressure system approaches the gulf at the start of next week. Only other concern might be some reduction in visibility due to marine layer low clouds especially on the leading edge of the ridge as it moves eastward. This marine layer is also anticipated to break down as the next low pressure system reaches the area.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ641-661.