textproduct: Juneau

SYNOPSIS

Key Messages:

- Multiple systems pushing into the southern panhandle will bring rounds of wintry precipitation to Ketchikan, Annette, and Prince of Wales Island.

- Potential for a weak front to move in Monday.

LONG TERM.../Sunday through Wednesday/

The long term forecast continues to be relatively uneventful, with only a few changes made. The northern panhandle is expected to stay mostly dry through the weekend and into early next week. Sunday looks to be more of a break day for the south, allowing the whole panhandle the chance to see breaks in the clouds as residual showers from the previous deteriorating low taper off. An upper level trough persists through the period with the southernmost tip largely remaining south of the panhandle, steering the bulk of the active weather into British Columbia and away from SE AK. A 500 mb low moves along the deepest part of the trough Sunday into Monday, proceeded by an upper level shortwave in the northern gulf. The surface inflection associated with the shortwave may bring light precipitation along the outer gulf coast of the panhandle through Monday, though this doesn't seem to have enough energy to make it much further inland than the outer coast.

A surface low following the upper level trough jumps into the southeastern gulf Monday afternoon, though it will still be too far south for the bulk of the frontal band to make it to the panhandle. Guidance currently suggests that the warm frontal band will catch up with the latter half of the shortwave band, which would bring a more organized band of precipitation through the southern and part of the central panhandle Monday night through Tuesday morning. This band may even make it as far north as the Icy Strait Corridor, and PoPs have been raised to reflect this. There is a potential this will just manifest as flurries for any location north of Angoon. Cold temperatures aloft (-8 to -10 degrees C) would keep most of this precipitation as snow, with the chance to mix into rain through midday as daytime temperatures rise. Daytime highs in the upper 30s to low 40s, combined with the increased sun angle, will make it so most snowfall does not accumulate until the evening or nighttime hours when temperatures decrease, especially for locations along the water.

The low is expected to depart quickly, dipping south Tuesday night into Wednesday. Uncertainty remains for the exact impacts through the early week, as model guidance is still somewhat split on the position of the low and resulting front. The GFS has come more in line with the EC, though still moving out of the area much faster and not lingering through Wednesday morning. Southerly winds will briefly increase going up through the inner channels with the frontal band, though they aren't expected to be very strong. Both before and after the low moves through, light outflow looks to develop with the pressure gradient tightening over Lynn Canal. This is only expected to reach up to 25 kts through Lynn Canal and Stephens Passage, as well as around Point Couverden and out of Cross Sound. This will help to keep skies clear through the northern panhandle and extending down through the central panhandle into the early week, potential clouding up more by Tuesday with the weak frontal band. Through Tuesday evening, depending on how quickly the low moves out of the area, skies will start clearing from north to south until a majority of the panhandle is seeing partly cloudy skies by Wednesday.

AVIATION

Aviation weather is mostly quiet across the panhandle except for lingering snow showers in the southern panhandle this morning occasionally bringing MVFR or IFR Vis or ceilings to an area. As of 4 am the lowest conditions are spread from Petersburg and Wrangell over to Misty Fjords, and at times on the west coast of Prince of Wales Island as well. Conditions in the southern panhandle are expected to gradually improve through the day as showers diminish in frequency. Eventually most areas should be mostly VFR by tonight. Otherwise mostly VFR conditions with lower winds, except Lynn Canal which has some gusty surface winds to 30 kt that could persist through the day before diminishing.

MARINE

Outside (Gulf and Coastal Waters): Light to gentle breezes continue across the Gulf waters this morning. These winds are expected to increase later this morning to gentle to moderate breezes as we see the low that has been lingering in the Gulf drop to the SE. High pressure is expected to build in briefly for the Gulf. Seas are expected to remain around 3-5 ft today with the swell direction shifting from southerly to W-NW during the day. The next system to impact the Gulf is expected to move into the area Monday.

Inside (Inner Channels): Northerly outflow winds are expected to continue today with strong breezes possible for the Lynn Canal and Taku Inlet areas. Elsewhere, winds are expected to be around gentle to fresh breezes. The outflow winds should weaken during the daytime hours as the pressure gradient weakens between the Inner Channels and Canada. These winds are then expected to increase again this evening as the gradient starts to tighten again with strong breezes becoming likely. Seas are expected to be around 3-5 ft with the outflow winds continuing while elsewhere, seas should be less than 3 ft.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ012-013.