Marine Weather and Tide Forecast for Thorne Bay, AK

SHORT TERM
/Through Thursday Night/...A mid-upper level low pressure system is slowly weakening across the central panhandle early this morning. While some of the heavier convective showers we saw in the evening have diminished, the moist southerly low level flow combined with just enough lift has produced additional scattered rain showers. This activity will slowly push northward through the morning, although precipitation amounts are expected to be light. Otherwise, some patchy fog has developed over the inner channels and along the northern Gulf Coast, including the Yakutat area, but thus far has not been as widespread as last night.

Precipitation chances gradually decrease this evening as upper level support further wanes. As cloud cover also decreases, especially late tonight, patchy ground and radiational fog will be possible. The next low pressure system will move northward off the coast of Haida Gwaii by late Thursday, bringing more rain as well as increasing marine winds to the far southern panhandle. The heaviest precipitation will likely not develop until Thursday night and beyond. At this time, no significant impacts are expected, but a few intervals of heavier rainfall are anticipated, especially south of Frederick Sound. More details can be found in the long term discussion below.

High temperatures today will generally be similar to Tuesday, just a few degrees cooler over the central panhandle due to increased cloud cover. But by Thursday, temperatures will warm once again in advance of the next low pressure system.

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
/Through 12z Thursday/...Rain showers continue to push through the southern and central panhandle overnight, bringing periods of MVFR to IFR CIGs of 1500 to 3000 ft and lowered VIS down to 2 to 4 SM. Low, thin clouds down to 500 ft are also being reported for many locations seeing heavier showers. These showers are mainly impacting areas from Frederick Sound southward, but will be possible for all locations across the panhandle as the band continues northward through the morning. Yakutat is the exception through the morning hours, with mostly clear conditions leading to patchy fog development over parts of the area creating periodic LIFR conditions. A majority of the panhandle can anticipate an improvement in conditions through the afternoon as showers diminish, with many northern locations potentially seeing clearing skies towards the end of the period. The associated area of low pressure to the south of the panhandle is expected to bring a swath of 20 to 30 kt easterly winds through the far southern panhandle overnight into Thursday. This will bring overcast CIGs with periods of showers through the southern and parts of the central panhandle by the end of the period and continuing into Friday.

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.