Marine Weather and Tide Forecast for Wrangell and, AK

SYNOPSIS

Key Messages:

- Widespread convective snow showers continue today and into early next week

- Outflow conditions develop through the middle of next week, with colder and drier conditions building into the panhandle

SHORT TERM
The strong low and front pushed through the panhandle Saturday and colder temperatures, decreasing winds and widespread convective snow showers in their wake. The stacked low and troughing will linger out over the northern Gulf with multiple troughs rotating around and into the panhandle. A noted trough pushing off the Kenai peninsula will rotate around the base of the trough and into the panhandle tonight, enhancing shower coverage and intensity. Snow showers could be moderate to heavy at times, but with the quick-moving nature of the showers, snow accumulations will be highly variable but generally should remain light (2-4 inches through Sunday night). Higher snow amounts will be possible closer to the coast, including Pelican, Sitka and across Prince of Wales Island where moist onshore flow will be enhanced. Winds continue to diminish today as the gradient relaxes as the low/front push further into Canada.

LONG TERM
Simply put: -Continued snow showers through mid-week, heavy at times, creating a complex snow forecast.
-Outflow build through the week, reaching peak intensity of gale force Thursday.

Monday two regimes will be present over the state of Alaska and Gulf: the first is a prominent ridge across the Bering Sea, the second a longwave trough across the ALCAN border stretching into the Gulf of Alaska. These systems will all contribute and influence weather across Southeast in the coming week into the weekend. Touching on the prominent ridge first, stout northerly flow downstream of the ridge’s axis will help reinforce cold air advection at 850mb, translating to relatively deep instability as cold air moves east across relatively warm ocean waters. This will serve as the catalyst for continued snow showers, some of them heavy at times. While snow showers move across the Panhandle Monday into Wednesday creating a complex snow forecast, a surface high strengthens in the arctic, with the longwave trough supporting a surface low in the gulf. As the systems develop the north-south pressure gradient will build, allowing outflow to increase across the northern inner channels. This cold and dry arctic air will help shunt snow further south through the week slowly, with showers coming to an end across much of the region by Thursday as gale force outflow reaches peak intensity. Friday outflow is expected to weaken slightly; however, winter will likely maintain its grip on Southeast as a closed low northwest of Hawaii lifts into the Gulf bringing moisture with it, which could result in an overrunning snow event.

AVIATION
/Until 18Z Monday/...Onshore flow, giving chances for snow showers, continues behind the front that moved through on Saturday, making flight conditions highly variable, with a diminishing trend in the showers generally improving conditions through the end of the period. LLWS values will be benign through the period. SFC winds may become gusty in & near snow showers. SFC winds will be gusty through the day today for the extreme northeastern panhandle / northern Lynn Canal area, including PAGY, due to an enhanced pressure gradient in place.

MARINE
Outside (Gulf and Coastal Waters): Winds and seas continue to drop today and will steadily decrease into early next week. Seas will remain hazardous to small craft, but the northern gulf seas drop from 12 to 16 ft to 8 to 12 ft through Monday, while the southern gulf will drop from 15 to 19 ft down to 10 to 14 ft. Seas dip further through midweek. Outflow conditions will develop through the week, with winds and seas increasing from Cross Sound on north off the coast.

Inside (Inner Channels): Winds and wave heights continue to diminish Sunday, with winds becoming moderate to fresh breezes and waves becoming 1 to 3 ft. Sunday night into Monday, winds are expected to flip in the northern channels as outflow develops.
Outflow winds will increase through midweek, with strong to gale breezes expected through most of northern/central inner channels.
Moderate to heavy freezing spray likely to develop for Lynn Canal and Glacier Bay.

AJK WATCHES/WARNINGS/ADVISORIES
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ022-053-641>644-651-652-661>664-671- 672.