textproduct: Juneau

UPDATE

update to the aviation and long term discussion.

SYNOPSIS

Key Messages:

- N winds in the northern panhandle will continue to increase this evening.

- Generally deteriorating conditions expected into Sunday.

- Strong storm force gulf low pressure system expected for Sunday night through Monday bringing rain and high winds.

LONG TERM.../Tuesday through Friday/

Active weather looks to continue for the long term period with multiple lows moving into the Gulf and subsequently past the panhandle bringing more rain and wind to the area. Starting Tuesday evening, the larger low which is expected to be near Kodiak will have a smaller, more compact low potentially in the around 970mb moving northward before phasing with the original circulation Tuesday morning. This will bring a reinforcing shot of moisture to the panhandle as well as more winds to the area. With cold air at 850mb in Canada sitting around -7C, it is possible that the northern panhandle could see some mixed precipitation, especially places not at sea level.

Behind these two lows, a third circulation looks for move into the area Tuesday night into early Wednesday morning which will bring another reinforcing round of moisture and wind. Once these lows dissipate, our attention then turns towards the potential of a low moving up the Aleutian chain and into the western Gulf Thursday. Current ensemble guidance shows this system crossing the Gulf Friday into Saturday while higher pressure remains the Interior and the Yukon. One thing that will need to be watched is if an of high pressure does develop as some ensemble members are hinting at. But at this moment, more members are agreement that a high does not form. The big area of uncertainty is the exact track and strength of this low as there is some divergence regarding this feature. Getting towards the end of the week, with some of the cooler air spilling over from Canada, it will be more possible to see some mixed precipitation for places like Haines, Skagway, and potentially Yakutat starting Thursday. The Icy Strait corridor could see some mixed potentially for next weekend if the guidance continues with the colder overnight lows.

AVIATION.../Through Sunday evening/

A disturbance pushing into the southern panhandle will spread multiple bands of showers south to north across the panhandle. MVFR flight conditions across the south this evening will gradually spread northward tonight through the panhandle. For PAHN, PAGY and possibly PAJN, colder temps from the persistent northerly flow could lead to some mixed precipitation and thus more VIS reductions. More MVFR flight conditions will be possible tomorrow as another band of showers spreads north across the panhandle. For PAYA, VFR flight conditions will likely prevail, but there will be a chance for light mixed showers Sunday afternoon that could bring brief MVFR flight conditions. Winds generally less than 10 kt, although PAGY, PAHN, PAKT and PAKW could occasionally see winds up to 15 kt. Elevated easterly winds up to 2kft aloft around 25-35kt through this evening could lead to LLWS for southern panhandle and through the Gastineau Channel near PAJN.

MARINE

The gale force low passing just to the west of Haida Gwaii tonight weakens over the southeastern GulfAK by Sunday morning. Gale warnings continue through 9 PM AKST this evening around the Dixon Entrance area and offshore to the west into the southeastern GulfAK zones. Over the inside waters, we continue several Small Craft Advisories over the inner channels tonight with enhanced northerly to easterly flow across the area. That outflow will be fairly short lived and not overly strong, with winds diminishing by early morning. Our attention then turns to Sunday night as we continue to see a fairly strong low (down to 955 mb) deepening over the central Gulf of Alaska Sunday night with the first wrap band/front of higher winds moving up the central and eastern GulfAK Sunday night through the day Monday. We have posted the Storm Warnings for the offshore zones (312/311) starting Sunday night...with potential winds 50 kt gusting to 60 kt and seas building to around 35 ft over the eastern and northern GulfAK Monday into Monday night. We will likely be adding the additional marine zones closer to the outer coast of SE Alaska later tonight to the Storm Warnings and Gale Warnings for that system on Monday.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Wind Advisory until 3 AM AKST Sunday for AKZ318-325. Winter Storm Watch from late Sunday night through late Monday night for AKZ318-319. High Wind Watch from late Sunday night through Monday evening for AKZ323-327-328. MARINE...Gale Warning for PKZ641-661. Small Craft Advisory for PKZ011>013-021-022-031-033-034-036-053- 642>644-651-652-662>664-671-672.