textproduct: Juneau

UPDATE...update to include 06Z TAF issuance

Only minor edits to the forecast this evening. The low out in the northern Gulf will slide south off the coast, with generally light to moderate snow continuing across the panhandle through Friday morning, ending from north to south through the day Friday as the low and front push away with high pressure building across the Yukon. Outflow increases on Friday as a result and will continue through the weekend. Much colder temps on tap for the weekend as well.

MARINE

Outside (Gulf and Coastal Waters):Thursday morning winds of gentle to moderate breezes were prevalent along the coast, with two primary wave systems present; the dominant was WSW swell of 3 to 6 ft at 12 seconds masking SE fresh seas of 1 to 3 ft from the south. Moving through Thursday a low will begin to mature in the gulf, with storm force northwest winds building out of Cook Inlet. These NW winds will build large NW seas, likely reaching near 20 ft in the central gulf, and some NW energy hitting the Chichagof, Baranof, and PoW coast, Friday. Strong gale to storm force outflow winds will also quickly build the northern coast Friday, spreading south into the weekend. The simple message is that mariners transiting our coast should be aware of strong outflow from major ocean entrances and inlets, bringing freezing spray and large northerly fresh seas of 18 to 20 ft. Favoring the coast will limit wave potential from limited fetch availability with the exception of Yakutat Bay, Chatham, and Sumner entrances, but then exposure to freezing spray is increased greatly.

Inside (Inner Channels):The simple message is that by this weekend most inner channels along and north of Sumner Strait will see gale to strong gale force conditions, with freezing spray. Major river inlets like Taku, Stikine, and Unuk, will see particularly intense conditions. Peak winds Sunday.

Winds of gentle to moderate breezes are a welcome treat early Thursday as a very diminished surface pressure gradient resides over southeast. This story will rapidly change Thursday night as the low-pressure system responsible for snow and light winds shifts south, increasing southerly winds to fresh breezes in the central inner channels. This is the first signal that conditions are about to change, with a rapid shift to northerly winds Friday morning, speeds quickly ramping up to gale force in Lynn Canal and Taku, strong breezes to near gales in Chatham and Stephens, by Friday afternoon. Conditions continue to deteriorate Friday night, with extensive gale force to strong gale force conditions over most passage along and north of Sumner Strait. Model Guidance is under doing winds in Sumner Strait, relying on historic data from poorly positioned surface observations that are sheltered from northerly winds, extreme caution is advised for mariners planning to transit the inside this week. You will encounter gale force winds, freezing spray, with the most extreme conditions in Glacier Bay, Lynn Canal, and Stephens Passage. Major river corridors like Taku, Stikine, and Unuk will also see gale to storm force winds and heavy freezing spray.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Winter Storm Warning until 3 AM AKST Friday for AKZ317. High Wind Watch from late Friday night through Sunday evening for AKZ318. Winter Weather Advisory until 9 AM AKST Friday for AKZ320-321- 324-325-330-332. Winter Storm Warning until 6 AM AKST Friday for AKZ322. Winter Storm Warning until 9 AM AKST Friday for AKZ323-328. High Wind Watch from Friday evening through Monday morning for AKZ325. Winter Weather Advisory until 6 AM AKST Friday for AKZ326-327- 329. MARINE...Storm Warning for PKZ053-651. Gale Warning for PKZ011>013-022-643-644-652-663-664-671-672. Small Craft Advisory for PKZ021-031-032-641-642-661-662.