textproduct: Juneau

SYNOPSIS

Key Messages:

- Convective showers with slight thunderstorm potential near Cape St Elias through Thursday night. Light rain showers continue across majority of panhandle from weakening low in eastern gulf

- Some clearing is possible for the Icy Strait corridor Thursday overnight. Areas of fog are possible during the overnight hours.

- Slightly above normal temperatures for Friday and Saturday with clearing skies.

LONG TERM.../Sunday through Wednesday/

The long term forecast continues to be relatively benign through the weekend, with shower chances building back in Sunday into early next week for the northern inner channels. Ridging over the gulf continues to build through the weekend, increasing gulf winds to a northwesterly fresh to strong breeze down the coast through the rest of the extended period and tapering off through Tuesday. The panhandle looks to stay dry Saturday, which will allow for widespread mostly sunny skies, increased daytime high temperatures, and developing sea breezes through midday. Shower potential will still be present through the period as flow turns more westerly and onshore, but Saturday continues to look drier and drier as it gets closer. With these clearing skies this weekend, much of the panhandle may see high temperatures reaching the high 60s and even the low 70s. 10 to 15 kt sea breezes should increase through midday for areas seeing significant clearing and subsequently warm daytime high temperatures. A tightening pressure gradient over Northern Lynn Canal looks to increase winds through Taiya Inlet and into Skagway through the early afternoon of both weekend days, which has the potential to bring winds up to 20 to 25 kts with any sea breeze influence.

The rest of the period is still relatively quiet for Southeast Alaska standards, but shower potential will increase Sunday and last through the early work week due to multiple upper level disturbances advecting across the northern gulf. An upper level shortwave trough in the northern gulf doesn't have much in terms of a surface inflection, but as the disturbance with increased vorticity pushes over the panhandle Saturday night, potential for showers increases for the northern panhandle and along the outer coast Sunday and through the rest of the period. Mid-level moisture looks to be lacking through this period, so any showers that do develop will most likely be weak and may not make it all the way inland over the panhandle. For much of the panhandle, this may just manifest as increased cloud cover or some light drizzle depending upon the formation of a marine layer. Even so, this will still decrease daytime high temperature potential to the low to mid 60s.

AVIATION

A weak low pressure system is continuing to generate MVFR to low VFR ceilings across much of the area. After 09Z tonight, light winds and breaks in sky cover may result in the formation of patchy fog for PAHN, PAJN, and PAGS. Any fog should quickly burn off by 15Z Friday. Farther south, occasional light rain and mist will be possible through much of the night with a general improving trend and prevailing VFR ceilings toward the end of the forecast period.

MARINE

Outside (Gulf and Coastal Waters): With an area of low pressure in the Gulf of Alaska, winds up to 10 kts have been observed. Friday, the low is expected to dissipate and a ridge will build-in behind it. From Friday into Sunday, this will lead to westerly winds 20-25 kts in the Southeast Gulf of Alaska and waves 5- 10 feet.

Inside (Inner Channels): Winds have been fairly light today in the inner channels. As a ridge of high pressure develops behind the trough in the Gulf of Alaska Friday, this will lead to breezy northerly winds up to 15 kts in Clarence Strait, and waves up to 4 feet. The high pressure will also lead to westerly 15-20 kt winds in Cross Sound. Overall, the strongest winds look to remain in the outer waters.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ641-642-661>664.