textproduct: Fairbanks

SYNOPSIS

A high pressure system over the Interior has compressed low level atmospheric moisture into widespread low lying clouds across the Western and Central Interior. A weak low pressure system moves around this high pressure now through Saturday pulling warm, moist air across St. Lawrence Island, through the Bering Strait and Chukchi Sea Coast, and then across the North Slope. Snow, periods of blowing snow, and periods of wintry mix/freezing rain are expected with this system. Colder temperatures are expected to return to the entire region early next week as a cold, dense airmass moves from the high Arctic towards the Bering Sea Sunday through Wednesday.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Quiet and dry conditions with strong inversions will continue across the Interior to finish out the week, with areas of low stratus and fog. Coldest valley locations will drop down to around -15F to -25F.

- An even colder airmass will build in out of the northeast early next week, supporting coldest valley locations dropping to around -20F to -35F Monday and Tuesday. Temperatures rise Wednesday through the end of next week.

- Light snow chances increase early next week across the Interior as moisture and gradually warming temperatures lift north from the Gulf of Alaska through midweek.

West Coast and Western Interior...

- Widespread precipitation will continue to lift northeast from St. Lawrence Island to the NW Arctic Coast Thursday into Friday. Snow, warming temperatures, periods of wintry mix, and southerly winds gusting 30 to 40 mph expected.

A. For St. Lawrence Island and the Bering Strait Coast: Mostly snow expected through Thursday evening with wintry mix and periods of freezing rain becoming more likely Thursday night into Friday morning. A winter weather advisory has been issued.

B. For the Chukchi Sea Coast including Kivalina: Snow and periods of blowing snow expected. Snow accumulations of 3 to 6 inches, highest near Kivalina. There is a slight chance for some very light ice accumulations embedded amongst the snow as temperatures warm Friday. A winter weather advisory has been issued.

- Areas of low stratus and fog across the West Coast and Western Interior continue to keep temperatures well above normal, with colder and clearer conditions favored to build back in late Friday into the weekend.

- A colder and drier airmass will build in out of the northeast early next week, supporting the return of widespread subzero temperatures and dry conditions. Light snow chances look to return by midweek next week. Temperatures warm once more in the latter half of the week.

North Slope and Brooks Range...

- Widespread snow chances and breezy winds will continue to lift northeast from the Bering and Chukchi Seas today into Friday, shifting east Friday into Saturday.

- Total snow accumulations through Saturday around 1-3", locally higher around 3-6" for Point Hope, Eastern Arctic Coast, and Central/Eastern Brooks Range including Atigun Pass around 3-6". Wind gusts of 25-40 mph will lead to areas of blowing snow at times. Winter weather advisories have been issued for Point Hope and the Eastern Arctic Coast.

- Well above normal temperatures will continue through Friday, with highs reaching the 20s to low 30s. A much colder and drier airmass will build in out of the northeast early next week, supporting the return of widespread double digit below zero temperatures and dry conditions.

FORECAST ANALYSIS AND DISCUSSION

For Thursday through Sunday. At the start of the forecast period Thursday, a broad ridging pattern remains established across most of Northern Alaska. A weak surface low moving from Siberia north and east across the Chukchi Sea and towards the Beaufort Sea Thursday through Saturday pulls large amounts of moist, warm air north from the North Pacific through the Bering Strait and into the far western Brooks Range Thursday and Friday. As the low moves east the warm, moist air following it covers the North Slope bringing snow across the region. Warmer than normal temperatures are expected through Friday for the West Coast and North Slope due to the influence of this system.

In the Interior large areas of low stratus and patches of fog lay underneath the ridge. Moist air in the bottom few thousand feet of the atmosphere is compressed under the ridge creating very widespread low clouds across Interior Valleys. Clouds diminish further east, especially southeast where drier low level air significantly limited cloud development. These cloudy conditions will continue in the Western and Central Interior so long as the ridge holds.

The ridge pattern is expected to hold through at least Saturday morning before a cold, dense airmass moves southwest from the high Arctic over Northern Alaska Sunday through Tuesday. Temperatures are expected to cool rapidly bringing most of the region well below 0 as the ridge breaks down early next week.

EXTENDED FORECAST DAYS 4-7

For Sunday night through next Thursday. At the start of the extended forecast period late Sunday, a cold, dense airmass moves towards Northern Alaska from the high Arctic. This feature will be strong enough to begin ridge breakdown and allows significantly colder air to move into the region early next week. As the ridge breaks down low pressure systems moving through the North Pacific can begin to influence the region. By Wednesday the cold airmass will have reached the Bering Sea allowing the upper level low around it to pull warmer, more moist air further north. Temperatures are expected to warm after Tuesday across Northern Alaska along with increasing chances of light snow across much of the Interior.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Winter Weather Advisory for AKZ801-814-815. Winter Weather Advisory for AKZ820-821-827. Winter Weather Advisory for AKZ805. PK...Brisk Wind Advisory for PKZ806-807. Brisk Wind Advisory for PKZ810-858. Brisk Wind Advisory for PKZ811-854-856-857. Brisk Wind Advisory for PKZ812. Brisk Wind Advisory for PKZ851. Brisk Wind Advisory for PKZ859.