textproduct: Juneau

UPDATE

Update to the AVIATION section to include the 18z TAF issuance. In short, no big changes from inherited forecast. MVFR improving to VFR today for the south. VFR for the north. Strongest winds in Haines and Skagway.

Overall forecast is still on track. Some minor edits to spots here and there over marine areas are possible but the overall trend and weather story remains will remain the same - improving weather today.

SYNOPSIS

Key Messages:

- Rain for the southern panhandle diminishes today as a weak system departs.

- Offshore flow is bringing colder temperatures and clearing skies to most of the panhandle.

- A dry Thanksgiving Day for most of the panhandle. The exception is the NE Gulf Coast (Yakutat, Elfin Cove, and Pelican) where some precip is possible.

LONG TERM

By Friday a series of disturbances will setup to impact the region through the start of next week; the first being a weak shortwave trough at 500mb reaching Kodiak by Friday morning. This feature will drive a gale force front and some moisture into the northern gulf and begin breaking down the outflow pattern. The second feature further upstream in the Pacific, an extensive storm force low, will tap into equatorial moisture, with the parent 500mb low beginning to steer a weak-to-moderate atmospheric river toward the northern coast by Sunday and additional fronts. The primary forecast challenge in the mid-range has been break down of outflow and timing of subsequent wind shifts allowing warmer temperatures to push into the Panhandle. These points in question have drastic implications to precip type at the surface for the central Panhandle. The published forecast has leaned heavily on warmer air at the surface, with no snow accumulations for communities outside of Haines and Skagway. The current forecast will need to be watched closely over the next 48 hours to see how cold surface temperatures can become and reassessing timing of precip and wind shift. Another item to watch is significant warm air advection Sunday into Monday, where freezing levels look to rise above 3,000ft for the entire region. Dense and wet snow this weekend in the mountains is expected, becoming moderate to heavy rainfall by Monday which could exacerbate river response in the central and northern region. At this time no significant flooding is expected.

To sum up, current forecast confidence for the communities along the Icy Strait corridor is rain/snow mix Friday becoming moderate to heavy rain Sunday with no snow accumulation. If temperatures are slightly colder than expected, there could be a period of wet/heavy snow that impacts Hoonah, Gustavus, and Juneau.

AVIATION

This morning, high-end MVFR to VFR is being reported around the area. Webcams support this. CIGS are around 2500 to 3000 in the south with higher CIGS in the north.

North panhandle TAF sites: Icy Strait corridor and northward, VFR improving to high-end VFR is expected today with VFR lasting through tonight and into tomorrow. For the most part, winds will be light over land areas. The exception is Haines and Skagway where northerly winds will remain around 15 kts with gusts to 25 kts.

For the inner channels, some pockets of stronger winds are being reported. Near Near Point Couverden has been having gale force winds. But the farther to you go away from this area, winds lighten up. Also, near Taku Inlet is blowing around 20 kts with those stronger winds potentially stretching down to Five Finger.

South panhandle TAF sites: A weakening low is fading out and tracking inland towards Canada. CIGS in the south are high-end MVFR to low-end VFR. The exceptions are near Metlakatla where CIGS are down to around 1800 to 2000 feet. And some Canadian sites are reporting CIGs down to 700 feet.

Going forward, these MVFR conditions will linger into the afternoon with gradual improvement later today. Winds will remain light but near gap-wind prone areas, like the Stikine Delta near Wrangell, will remain elevated through today. No major LLWS concerns, but winds aloft will be variable through the afternoon around 15 kts as the low dissipates.

MARINE

Outside: Wind speeds decreasing into Wednesday night before a disorganized front in the central gulf brings southeasterly strong breezes to near gale force sustained winds (22 to 33 kts) with gale force gusts (34 to 40 kts) to the northern gulf into Thursday. Wave heights of 7 to 9 feet continue to diminish into Thursday before increasing to 11 to 14 ft with the next front. Outflow winds coming out of channel entrances may stay relatively elevated up to fresh breezes (17 to 21 kts) through Thursday.

Inside: Outflow winds continue to blow through the channels overnight into Wednesday, bringing fresh breezes (17 to 21 kts) with areas of strong breezes (22 to 27 kts) out of Lynn Canal, Taku Inlet, and other outflow areas. Isolated areas of the panhandle such as Point Couverden have seen periods of near gale force sustained winds overnight, though strongest winds will decrease to moderate to fresh sustained breezes (11 to 21 kts) with weakening outflow through mid week. Wave heights around 3 to 4 ft will also diminish to 2 to 3 ft into Thursday, though areas of strong outflow and channel entrances may still see heights around 5 ft through Thursday morning. Outflow will continue to weaken through Thursday night as the pressure gradient begins to turn.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ641>644-651-652-661>664-671-672.