textproduct: Juneau

UPDATE

Update to the aviation section, along with cloud cover update. The Icy Strait area including Juneau looks to begin to clear out earlier than expected, early to mid afternoon from easterly downsloping winds.

SYNOPSIS

Key Messages:

- Showers continue today for the central and southern panhandle before diminishing by evening.

- A somewhat stronger system will bring rain and increased marine winds to mainly the southern panhandle Thursday into Friday.

LONG TERM.../Friday through Sunday/

An area of low pressure remains southwest of Haida Gwaii Friday allowing for showers to continue over the panhandle. Similar to what we have been seeing, the highest rain totals and heaviest rates look to remain over southern areas. There is a chance for isolated thunderstorms to develop across on Friday shortwave moves over the area. Similar conditions will continue into Saturday as the low moves eastward allowing for some easterly flow to continue into SE AK. Although there is signs of convection, confidence on thunderstorm development remains low at the moment. If thunderstorms do develop, periods of gusty winds and heavier rain are likely to occur. We will continue to monitor as we get closer to the weekend.

As the low pressure system moves eastward, an area of higher pressure takes its place in the gulf. This could help to create slightly warmer weather for late in the week. This will also help to create drier weather for the end of the weekend. High temperatures are likely to reach into high 60s to the low to mid 70s. Warmest locations look to be across the north where cloud cover will remain lower. As this higher pressure builds, it will also allow for winds over the gulf to become northwesterly for the weekend. Strongest winds will be over the NE gulf into Icy Strait and Lynn Canal. Otherwise, overall winds remain on the lighter side, at or below 15 kts, for the long term forecast period.

AVIATION

Main pain points for the aviation forecast for the northern half of the panhandle are weak winds, low clouds AoB 2000 ft, and misty/foggy conditions with visibilities one mile or less. While these low visibility conditions may not be occurring over TAF sites, FAA webcams are certainly showing nearby low visibility. Haines in particular, has low visibility just offshore that will be lifting during the late morning to early afternoon. Otherwise, a weak wave is moving northward towards the Icy Strait area during the late morning to early afternoon, which may bring intermittent MVFR clouds to around 2500 ft. By late afternoon, VFR conditions will return with few to scattered clouds.

For the southern panhandle, continuous southerly, moist flow will keep MVFR CIGs in the forecast for much of the day, particularly for the far southern panhandle including Ketchikan. It does look like CIGs will lift to VFR in the early evening, but confidence is low. Furthermore, expecting the showers to slightly decrease in frequency during the day, before the next round overnight tonight for the far southern panhandle.

MARINE

Outside (Gulf and Coastal Waters): Relatively benign winds overnight are expected to increase to an easterly fresh to strong breeze through Dixon Entrance and into the southern gulf through Wednesday. Primary concern for mariners transiting Dixon Entrance, Cordova Bay, and the west coast of PoW for elevated ESE winds. For most of the coast, inspiring fetch windows remain closed; sea state continues to be dominated by low amplitude ground swell from far away equatorial and South Pac storms driving significant wave heights of 2 to 3 ft. Thursday, the exception will be for coastal waters south of Cape Ommaney where the ESE winds mentioned above will generate easterly wind waves of 6 to 8 ft, dominating underlying swell. In the offshore zones west of PoW expect seas of 9 to 11 ft. Kept winds relatively the same for the forecast overnight, but higher wave heights reaching slightly more north along the coast gave reason to slightly expand the area of small craft advisories for today and into Thursday.

Inside (Inner Channels): Southerly winds continue to build in Clarence Strait, persisting through Wednesday at a fresh breeze as an additional low sets up southwest of Haida Gwaii. Expect some gusty southerly winds of 15 to 25 knots to move north into the central inner channels through Wednesday afternoon. Overnight Wednesday, winds begin to turn easterly in Dixon Entrance, with strong breezes to near gale force winds forecasted. Mariners transiting the Inside Passage should be aware of elevated northeast to east winds impacting southern Clarence Strait and Revillagigedo Channel. Furthermore, by early Thursday, these winds will generate seas of 4 to 6 ft, mainly impacting southern Cordova Bay and south of Gravina Island. The rest of the northern inner channels will stay relatively uneventful through the period, with the possibility for a sea breeze to turn winds onshore midday. Lynn Canal may see northerly winds increase to 10 to 15 kts overnight once any lingering sea breeze influence subsides.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ641-642-661>663.