textproduct: Juneau

SYNOPSIS

Key Messages: - Cold temperatures continue, with many areas seeing single digits to teens for overnight lows, with some areas in the NE panhandle dipping to the single digits below zero. Dangerously cold wind chills continue along White Pass.

- Clearing skies & drier conditions are in store for the rest of the work-week.

- Continued strong outflow winds will keep the cold air in place through the weekend for the northern panhandle. Marginally warmer air moves into the southern panhandle this weekend with snow becoming likely.

SHORT TERM.../Through Tonight/

Clearing skies, cold, dry, & windy northeasterly outflow conditions, strongest over the northern panhandle, continue with a gradual diminishing trend in the winds starting late tonight through friday as the pressure gradient relaxes a bit. The wind chill at White Pass has gotten down to as low as minus 51 as of 5:30am AKDT. An Extreme Cold Warning remains in effect for the Municipality of Skagway & the Klondike Highway until 9am AKDT Friday. A Cold Weather Advisory remains in effect until 9am Friday for the Haines Borough & the Haines Highway for wind chills as low as 25 below. It has been very lightly snowing in the Petersburg & Kake area overnight. This will taper-off as very weak localized troughing over that area diminishes into the morning hours.

LONG TERM.../Friday through Monday/...Only minor changes were made to the long term forecast, mainly adjusting outflow wind timing and beginning to narrow down timing on the potential snow for next weekend into early next week.

Strong outflow winds continue to hold any developing showers offshore until Saturday morning, keeping the panhandle dry with partly cloudy skies through the rest of the week. A small surface ridge developing on Friday is expected to make that day the most clear and the least windy, though outflow winds will still be elevated to around 20 kts in the strongest areas. Precipitation is expected to return to the forecast Saturday morning as a low jumps into the southern gulf and sends a front northward into the panhandle. The precipitation will mainly impact the southern panhandle over the weekend, extending north to the central and parts of the northern panhandle through Sunday into next week. Uncertainty still remains in how far this front will make it up the panhandle, as persisting outflow winds will attempt to force the front to stay more south. With colder temperatures remaining through the long term forecast, precipitation will most likely fall as snow for the northern panhandle. The front will bring slightly warmer temperatures around freezing with it to the southern panhandle, making it possible for this precipitation to mix for parts of the weekend. Active weather looks to remain into early next week.

The main impacts for the long term remains the temperatures and winds. The arctic boundary sits just south of the panhandle through the rest of the week, keeping below freezing temperatures through much of the extended forecast. Daytime highs will struggle to reach into the 20s for many locations in the northern and central panhandle, and into the 30s for the southern panhandle. Overnight lows during the week will mostly stay in the single digits up north and in the 10s down south, slightly increasing through the weekend as the next system moves in. Uncertainty remains on southern panhandle temperatures through the weekend, as models are starting to depict the arctic boundary shifting just north of this area allowing the front to bring temperatures in the mid to upper 30s to some of these southern locations. This makes snow potential even more uncertain, as there may be times where these temperatures reach above freezing enough to turn to a rain/snow mix or even just rain for periods. This boundary looks to shift back down south into early next week, keeping the cold temperature trend in the extended forecast. An extreme cold warning for Skagway, primarily along the Klondike Highway, has been reissued through 9 AM Friday for extremely cold wind chill temperatures as low as 55 degrees below. The cold weather advisory for the Haines Borough has also been reissued through 9 AM Friday for wind chills as low as 25 degrees below, primarily once the sun sets. Strong outflow also persists through the week, with 20 to 35 kt winds and pockets of gales blowing through the inner channels and funneling out into the coastal waters of the gulf. The strongest winds will remain in the northern panhandle, particularly down Lynn Canal and Stephens Passage and out of Cross Sound, with gaps along the gulf coast serving as outlets for strong winds to funnel through. There will be a brief decrease in wind speeds on Friday, though Lynn Canal will still stay above 20 kts before outflow ramps up even stronger than before going into the weekend. Strong gales are expected to spread through a majority of the inner channels, with strongest winds remaining in those hot spots in the northern panhandle. Freezing spray will remain an issue in the inner channels and along the NE gulf coast with these elevated winds, which could become heavy at times.

AVIATION.../Until 12Z Friday/

Largely VFR conditions expected to continue across the majority of the panhandle through the TAF period, as northerly outflow winds and diminishing precipitation lasts throughout the day. The main areas continuing to see precipitation are over the central panhandle between Kake and Petersburg, with snow expected to continue into later this morning, bringing MVFR conditions from cloud ceilings AoB 2500 ft with VIS drops between 2 and 4 SM as snow decreases visibility at times. This will soon push through by between 16 and 18Z when conditions will improve to VFR. Lower CIGs to between 2000 and 3000 ft last over the southern panhandle this morning is also expected to begin to clear up by 18Z, with Ketchikan seeing MVFR conditions from these lowered ceilings seeing improvement by that time as the cloud cover moves through. Skies will fully begin to clear up by around midday across the panhandle as offshore flow keeps the skies cleared and keeps the precipitation around a weak low in the central Gulf offshore and away from the panhandle today. With this continued offshore flow and outflow winds from the northeast keeps winds in Skagway at the surface between 25 and 35 kts with gusts up to 45 kt. Juneau continues to see some cross barrier flow from the NE winds at the ridgetop, however these will be relatively weaker and remain between 25 and 30 kt between 1500 and 2000 ft. The majority of the TAF sites that are not impacted by the outflow winds will see more light and variable winds at the surface, with occasional gusts for Haines, Wrangell and Klawock to 25 kt. Haines, much like Skagway, will see some northerly outflow with gusts to 25 kt in the morning and sustained NW winds reaching around 15 kt into tonight.

MARINE

Inside Waters: Generally, the northeasterly outflow pattern continues for the next several days, keeping up to around 40 kt gale-force sustained winds for the northern 2/3 of the Inner Channels with stronger winds the farther north that you go, with Northern Lynn Canal experiencing the strongest winds. These winds will also be accompanied by fully-developed seas up to around 15 ft, with generally the highest waves the more northward you go, due to the long-fetch of these strong winds. Additionally, mainly due to air temperatures being so cold, up to heavy freezing spray is also likely for those areas.

Outside Waters: Generally, northeasterly outflow winds up to around 35 kt gale-force are in store for the northeastern gulf through tonight. For Friday, the pressure gradient relaxes & winds decrease. Finally, those winds ramp-up, again, up to around 40-45 kt gales for the same area for the weekend as the pressure gradient tightens & northerly outflow intensifies, once again. Significant wave heights top out at around 11 ft today & top out at around 22 ft for the weekend. Some freezing spray is possible for the northeastern gulf.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Extreme Cold Warning until 9 AM AKST Friday for AKZ318. Strong Wind until noon AKST today for AKZ318. Cold Weather Advisory until 9 AM AKST Friday for AKZ319. Strong Wind through late tonight for AKZ325. MARINE...Heavy Freezing Spray Warning for PKZ011-012-031. Heavy Freezing Spray Warning for PKZ013. Heavy Freezing Spray Warning for PKZ032. Heavy Freezing Spray Warning for PKZ053. Gale Warning for PKZ011>013-651. Small Craft Advisory for PKZ021-022-031>034-053-641>644-652- 661>664-671-672.