textproduct: Juneau

SYNOPSIS

Key Messages:

- Chances of showers linger before a front brushes the southern panhandle with light rain and gusty winds Sunday

- Leaning towards drier and slightly warmer conditions for early next week, particularly for the northern panhandle.

LONG TERM.../Tuesday through Saturday/

The forecast for the work week remains largely consistent with yesterdays forecast, though precipitation accumulations are trending slightly drier as upper-level support weakens. Starting Tuesday morning, persistent onshore flow is likely to develop as the low in the Gulf dissipates and high pressure replaces it. Additionally, a weak front is forecast to track across the southern panhandle bringing with it lighter precipitation rates. The pressure gradient will tighten across the northern region with this frontal passage, leading to elevated winds for Lynn Canal and Taiya Inlet, though current trends suggest weaker than initially thought.

Due to a lack of upper-level forcing, any showers throughout the week are anticipated to be primarily terrain-driven, characterized by onshore flow and mainly isolated to the higher elevations. The region looks to sit under a weak upper-level trough until Wednesday morning, after which a surface ridge is expected to begin building on Thursday. Winds will pick up Friday afternoon as another weak front moves through, preceding the strengthening of the ridge. Moderate rain showers are then forecast to move across the panhandle from Friday evening through Sunday.

While temperatures will remain seasonably cool through the week, there is higher confidence in a slight warming trend for the upcoming weekend as the region settles under an upper-level ridge and 850mb temperature anomalies trend warmer. Increased cloud cover will also help to keep minimum temperatures warmer. By the end of the week, a stronger Aleutian low is expected to track toward the western Gulf. This system is expected to weaken as it enters the Gulf and recent model guidance is starting to agree on its track trending westward, which should reduce its impact on Southeast Alaska.

AVIATION

There is a fairly weak low pressure system in the Gulf of Alaska and an associated front. While weak, some showers due to marine layer clouds have brought lower ceilings (AoB 1000 feet) and visibilities (less than 2 miles) to Yakutat. As daytime heating continues, this activity is expected to dissipate.

The front is expected to bring shower chances for areas mainly south of Fredrick Sound. The low pressure system is forecast to meander in the Gulf, and lead to continuing rain chances through the end of the TAF period. Where showers form, MVFR ceilings are possible. Across the Southern Panhandle, including Ketchikan, gusty winds up to 20 kts are expected as the front impacts the area.

As of now, winds look to stay below LLWS criteria for the Southern Panhandle. After sunset, winds and rain chances across the area are expected to diminish.

MARINE

Inner Channels: Quiet morning across the inner channels with mostly 15 kt or less south to east winds. Clarence Strait will start seeing winds up to 25 kt as early as midday as the front that is just offshore moves farther inland. Those winds should persist into tonight before diminishing Monday morning. Otherwise most other areas of the panhandle will see lighter winds as the front is not expected to move any farther north then the southern panhandle. However, a flip of wind direction from S to N is expected for many areas this afternoon and evening. Seas are mainly expected to be wind wave up to 4 ft with up to 6 ft in Clarence Strait today into tonight due to the higher winds there.

Gulf Waters: The same front that will stall over the southern panhandle is affecting a large portion of the gulf today. Expect 20 to 25 kt E winds across most of the gulf waters today due to the front. Those winds will gradually diminish Sunday night and is expected to be less then 15 kt for most areas by Monday afternoon. Wind directions then flip to more N or NW Monday night. Seas are 7 ft or less across the gulf this morning with 3 ft or less swell. Potential for 8 ft seas along the front today into tonight, but expect gradually subsiding seas Monday into Monday night as winds diminish and swell remains nearly non existent.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ036-641-661>664-671-672.