textproduct: Juneau

SYNOPSIS

Key Messages:

-Lingering showers diminish through Saturday evening.

-An unseasonably strong system impacts the southern half of the panhandle Sunday. With bands of rain, gale force winds in the Dixon Entrance, and breezy conditions for southern Prince of Wales and Annette Islands.

-Conditions improve Monday as the system departs.

LONG TERM

/Monday night through Wednesday/ Following the system tracking into the Gulf this holiday weekend, ridging is expected to build starting Monday night into Tuesday, bringing warmer temperatures, clearing skies and little to no precipitation, though clouds over parts of the southern panhandle might struggle to completely clear out. A subsequent low pressure system is anticipated to move into the Gulf from the Bering Sea between Wednesday night and Thursday morning. A shortwave trough ahead of this low will cross the panhandle late Tuesday night, causing an increase in southwesterly winds and gustier conditions, primarily Frederick Sound northward. Despite consistent timing across ensembles, uncertainty remains regarding the Bering Sea low's strength and placement in the Gulf, with the GEFS model ensemble favoring a deeper trending trough midweek.

This period is expected to be wetter across the panhandle, with a 75% confidence of 24-hour precipitation totals ranging from 0.65 to 1.0 inches across the panhandle, and generally increasing farther inland and north. Colder mid to low-level temperatures and steeper lapse rates could provide additional dynamic forcing to increase precipitation rates as the front passes Tuesday night. Weak ridging is expected to form on Wednesday post-front, leading to more zonally oriented onshore flow and light showers for the remainder of the week. Minor warming is expected to begin towards the end of next week, but temperatures will still remain climatologically cooler.

AVIATION

/06z Sunday to 06z Monday/ Isolated showers are still passing over the area with PAJN gett ing its first shower of the day just before 5z. Showers will trend down overnight, but think that the convective nature of the atmosphere should limit fog potential for Sunday morning. A large low pressure system tracking east across the north Pacific will shift flow across the region to offshore (E-N) by 12z. Due to the offshore wind direction, CIGs will take longer to lower as rain reaches the far southern zones through mid-morning Sunday. LLWS out of the SE-E will affect these sites (PAKW, PAKT, southward) with as well with wind increasing to around 35kt at 2kft. VFR conditions likely for areas north of Frederick Sound, potentially north of Sumner Strait. The northern areas will see winds turn out of the north overnight, then shift to their sea breeze direction in the late morning. Currently, the worst conditions look to be PAKW, PAHY, PAKT, and PAMM from these strong southeasterly winds and moderate rainfall rates. CIGS and VSBY improve Monday with breezy NW winds and sea breezes.

MARINE

Outside (Gulf and Coastal Waters): Another excellent day in Alaska. As of 1000am local, ASCAT wind passes and coastal buoys were all reporting speeds less than 20 knots and excellent southwest swell 6 to 8 ft at 15 seconds. Not a bad day along the coast. This story will change overnight as the southwest swell decays and a gale force low undercuts the Gulf of Alaska, heading toward Haida Gwaii. Anticipate easterly winds to build along our coast Sunday morning as this low moves east, driving gale force winds for areas south of Cape Decision by Sunday afternoon. Mariners operating directly in the lee along the western coast of PoW will be protected from larger wave development; however, as this low ejects into Canada Monday, northwest winds of fresh to strong breezes will build along the coast. Mariners should be aware of this threat as protected areas from east-southeast winds will feel northwest winds and seas by Monday.

As this low departs, a large storm force low will develop along the Aleutians, with a significant fetch of SW winds generating large seas. Anticipate these seas to transition to swell as it moves toward our coast, with some wave guidance suggesting 12 to 15 ft near 16 to 18 seconds by Wednesday.

Inside (Inner Channels): Winds were relatively calm Saturday morning across the inside, with most sites at or below 20 knots. Strongest winds were in Lynn Canal and near Cape Decision, with 15 to 20 knots early today. Main system of concern is currently tracking east in the far southern Gulf of Alaska. As this low moves south of the Panhandle Sunday, anticipate northerly winds to build through the inner channels along and north of Frederick Sound, likely reaching moderate to fresh breezes, especially in Chatham and Sumner. In Clarence Strait southeasterly winds of fresh breezes to strong breezes will be the theme, with a few hours of gale force conditions likely south of Gravina Island and into Revilla and Cordova Bay. Timing for the strongest winds will be near 3pm to 8pm before winds begin to slowly trend a bit downwards through Monday, becoming northwesterly, remaining above 15 knots.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Gale Warning for PKZ036-641-661-662. Small Craft Advisory for PKZ011-012-642>644-663-664-671.