Marine Weather and Tide Forecast for Kupreanof, AK

SYNOPSIS

- A low in the northern Gulf of Alaska will keep sending periods of moderate to heavy snow showers across the northern and central panhandle. Due to the showery nature of the snow, accumulations will be highly variable with periods of melting in sunny breaks. Winter Weather Advisories have been extended and expanded through Thursday morning.

- A strong low may move up from the south and impact the panhandle over the weekend.

SHORT TERM
(Through Thursday night)
No major changes to ongoing forecast as a low in the northern gulf sends continues scattered to numerous snow showers across the panhandle. Looking around the area, showers have been moderate to heavy at times through the morning and afternoon with visibilities frequently dropping to 1SM and as low as 1/4 mile.
Main caveat however is that snow is having a hard time accumulating given mid March day time heating with temperatures rising into the low to mid 30s across the Icy Strait corridor, upper 30s to low 40s southward towards Prince of Wales Island.
Rather than chase the snow showers, opted to issue longer duration Winter Weather Advisories through Thursday morning with more spatial spread in accumulations across the central and northern panhandle. Another organized band is likely to push through the area late Tuesday night through Wednesday morning with additional snowfall accumulations of 6 to 12 inches expected through Thursday. Forecast challenge going forward are that snowfall accumulations will be widely variable across the advisory areas due to the hit or miss nature of the showers, however, rates as high as 1 inch per hour will be possible within any heavier showers that repeatedly move over the same location. Heaviest snowfall currently forecast to be centered along the Cape Fairweather to Lisianski Strait area. These snow showers will continue to be scattered to numerous through tonight, with higher confidence of accumulating snowfall. Any current advisories could be upgraded to short-fuse Winter Storm Warnings if heavier snow showers continue over the same area.

By late Wednesday night, a stronger front will push into the panhandle, bringing a more organized cluster of snow showers and likely heavy snowfall back across the northern and central panhandle. This system will be the next potential Some deterministic guidance hinting at triple point low developing along the Baranof coast by early Thursday morning and inland NE through early Thursday afternoon. This system will be monitored and could be the next potential big snow maker heading into the weekend.

LONG TERM
(Friday through the weekend)
Low pressure is expected to remain in the Gulf of Alaska for the start of the long term period. This will continue to bring showers to the panhandle with rain and snow possible. With high pressure remaining in the Bering Sea, colder air will continue to move down the back side of the high pressure and into the low positioned over the Gulf. This will help to reinforce the showers.
With the breaks between showers, temperatures will have the opportunity to rise during the day time hours with the increasing amount of daylight being experienced. This will also help to limit accumulation amounts during the daytime. Potential for accumulating snow looks more favorable during the evening and overnight hours.

For the extended portion of the long term forecast, we continue to look cooler than normal for this time of year with near normal to above normal potential for precipitation across the panhandle.

AVIATION
/Through Thursday evening/...
Scattered to widespread showers are expected to continue through the TAF period with conditions dropping down to IFR to LIFR in heavier showers, especially from Icy Strait Corridor northward.
Most places are expected to see snow showers, especially from PASI to PAPG northward. However, places across the southern panhandle could see rain instead of snow, especially during the lighter showers. Outside of the showers, conditions are expected to improve to MVFR and VFR as ceilings and visibilities improve.
Winds will generally be around 10kt or less through the period, but could be a bit strong up to 15kt for PAYA, PAHN and PAGY.

MARINE...
Inside (Inner Channels): Winds have become predominantly southerly across the inside channel. The one place that continues to see northerly winds is over N lynn Canal. Winds over N Lynn Canal are anticipated to become southerly tonight into tomorrow with the exception of the far north near Taiya Inlet. Strongest winds remain over Stephens Passage from Midway Island to Five Finger Light House with gusts up to 40 kts. Otherwise winds across the inner channels remain around moderate to strong breezes, 10 to 20 kts. Significant wave heights remain around 2 to 4 ft across the area, with slightly higher waves across Stephens Passage, Cross Sound and ocean entrances.

Outside (Gulf and Coastal Waters): A broad low will remain in the northern Gulf of Alaska through the duration of the week, bringing with it winds of 20 to 30 kt and isolated areas up to 35 kts possible in the far northern gulf. Winds across the southern gulf will be predominately W to SW while winds across the northern gulf will be predominately E to NE. There will likely be times of gusty winds and variable winds as the broad low sends showers through the gulf into the panhandle. Waveheights will remain more on the unsettled side, with 8 to 12 ft expected with southerly swell continuing through mid week. Over the weekend, a strong low moves up from the south.

AJK WATCHES/WARNINGS/ADVISORIES
PUBLIC...Winter Weather Advisory until 10 AM AKDT Thursday for AKZ317>321- 323>326.
Winter Weather Advisory until 4 AM AKDT Wednesday for AKZ322.
Winter Weather Advisory from 7 PM Wednesday to 10 AM AKDT Thursday for AKZ322.
Winter Storm Warning from 4 AM to 7 PM AKDT Wednesday for AKZ322.
Winter Weather Advisory from 4 AM to 10 PM AKDT Wednesday for AKZ328.
MARINE...Gale Warning for PKZ652-672.
Small Craft Advisory for PKZ022-031-053-641>644-651-661>664-671.