textproduct: Juneau

SYNOPSIS

Key Messages:

- Upper level low will spread lighter rain further north tonight with diminishing heavier showers likely south of Frederick Sound. - Showers diminish Wednesday before another system approaches the southern panhandle Thursday bringing more rain and increased marine winds. - Lighter winds will generally prevail Tuesday, with occasionally breezy winds for southern panhandle in the vicinity of heavier showers and near Skagway.

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

Tuesday afternoon heavy rain showers continue to expand over the south, moving north into the central Panhandle. As of 1500 AKDT strongest showers are south of Frederick Sound. Primary impact is VFR quickly shutting down to MVFR/IFR VSBY/CIGS from SHRA, along with gusty winds. So dont let any VFR sucker holes trick you to push into strong conditions; CIGS AoB 2000ft, VSBY down to 2SM, and variable gusts to 20 knots under the strongest showers. Some of these clouds may overdevelop enough to bring a lightning strike or two. Overnight tonight southerly winds continue to slowly build for Clarence Strait/PAKT and Prince of Wales, with generally 10 to 20 knots expected to persist. We could see IFR CIGS for southern locations Wednesday morning, slowly lifting to MVFR through the day.

For folks along and north of the Icy Strait Corridor, VFR prevails until later this evening as rain expands across the north, bringing widespread MVFR by early Wednesday.

MARINE

Outside (Gulf and Coastal Waters): Tuesday morning a low was moving into Prince of Wales (PoW), with Dixon Entrance and coastal locations west of PoW bearing the brunt of moderate to fresh breezes. Moving north toward the Fairweather Grounds, NW winds were also prevalent, with moderate breezes as well. Sea state along the northern coast continues to be dominated by ground swell, 19s at 1-3 ft from the south, with building 4 to 6 ft NW wind waves as you move from the Fairweather Grounds south to Dixon; highest waves west of PoW and Dixon.

Into Tuesday evening winds NW winds of moderate breezes expand slightly west toward Cape St. Elias. For the Central and Southern coast, wind begin to decrease as the responsible lows pressure gradient weakens. Anticipate a brief respite into Wednesday morning; however, this will be short lived. A more prominent low will set up residence in the SE Gulf, increasing ESE winds across southern waters to fresh to strong breeze. 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.

Inside (Inner Channels): Tuesday afternoon winds of 15 to 20 knots are in Taiya Inlet and Clarence Strait, with other areas seeing less than 15 knots of wind. Southerly winds continue to build overnight in Clarence Strait, persisting into Wednesday, as an additional low sets up southwest of Haida Gwaii. Expect some gusty southerly winds of 15 to perhaps as high as 25 knots 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 Revilla Channel (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.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ641-661-662.