textproduct: Juneau

UPDATE.../to add the 18Z aviation discussion/

SYNOPSIS

Key Messages:

-Rain returns to the northern panhandle on Thursday, as a front moves through

-Chances of showers linger into the weekend.

LONG TERM.../Saturday through Tuesday/

Surface ridging looks to shift slightly south and east of the panhandle on Saturday, with weak onshore flow allowing for light rain showers and cooler temperatures. For Sunday onward, deterministic and ensemble guidance widely varies between models and model run to run differences with the handling of the next system traversing through the Gulf. GFS and especially Canadian guidance favor sliding the low south of Haida Gwaii, with drier offshore conditions north across the panhandle. However, the GFS ensemble trend has tracked a bit further north and more online with the EC deterministic and ensemble guidance, which brings the low further north into the eastern gulf with with multiple troughs/fronts pivoting north through the panhandle. Have leaned towards the EC solution and bring rain into the panhandle, although cap PoPs as confidence in this solution is only moderate this far out due to the large spread in model guidance. The best potential looks to remain south of the Icy Strait corridor. Keep a chance of showers into Tuesday, although the trend is looking to be drier as most guidance has the low shifting southeast of the panhandle with ridging building back in behind it.

Southeasterly flow looks to increase ahead of the low over the weekend, possibly reaching small craft criteria along the outer coastal waters and inner channels, especially into Clarence Strait on Sunday. Seas also trend up in the eastern Gulf and ocean entrance of the southern inner channels, possibly climbing to 10 ft. A downward trend in marine conditions is expected early next week as the low shifts off to the south and east.

AVIATION.../Until 18z Friday/

Bands of rain showers & lower CIGs originating from an area of low pressure centered to the southwest of the panhandle are continuing to move from south to north over the Southeast Alaska region. This will continue on & off through the TAF period. These bands will periodically lower CIGs & VISs down to within the MVFR flight category through the period. SFC winds will be on the rather breezy/gusty side through this evening for the northern Lynn Canal(PAGY & PAHN) area, especially for PAGY, due to a tightened north to south pressure gradient in place over that area. SFC winds look to become a little bit elevated for the PAKT area through this afternoon, as well. LLWS values remain relatively benign through the TAF period.

MARINE

A low S of the panhandle will slowly move E into BC through the remainder of the week. A remnant frontal band from the low will linger over the panhandle before falling apart through Friday. A ridge begins to build over the E Gulf over the weekend.

Outer Waters: Small craft advisory seas build over the southern Gulf Thursday as a low S of the panhandle traverses E. Seas begin to diminish by late Thursday night. By Friday, seas in the outer coastal waters of 5 to 7 ft are expected. Seas will remain 5 to 7 ft until Sunday when wave heights build back to 8 to 10 ft. SW swell of 2-4 ft on Thursday, with the largest swell in the southern outer coastal waters. Swell diminishes to 1-2 ft on Friday.

Inner Waters: Winds over the inner waters will fluctuate between 10 to 15 kt through the day, with wind speeds spiking upwards as frontal bands move through. Lynn Canal and Clarence Strait will likely remain on the stronger side, with these areas in particular likely to see winds of up to 20 kt - or even 25 kt in the case of the Clarence Strait ocean entrance.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ036-641-661-662.