textproduct: Fairbanks

SYNOPSIS

Unsettled weather will continue through the weekend as persistent moisture gets fed into Northern Alaska. North of the Brooks Range, stratus, areas of fog and well below normal temperatures will be the main story moving forward. Otherwise, from the Brooks Range southward, rain and snow showers are expected and will be mainly unimpactful outside of a couple of slick spots in shady/elevated spots. The one exception is Isabel Pass south of Trims Camp where we expect snow, heavy at times today through Saturday afternoon. A Winter Weather Advisory is issued and has more details. Isabel Pass and the Central/Eastern Interior will see snow and rain lessen in coverage Saturday evening into Sunday. By this time, the next low will be felt in SW Alaska with snow, gusty wind and low visibility. Afterwards there is an abundance of uncertainty with where the moisture goes and this will be expanded on in the Extended Forecast Discussion.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Rain and snow showers persist in the Interior with steadier snow moving into the southern AK Range through Saturday. * Snowfall totals will generally be less than 1 inch in the Interior and around 6 to 12 inches south of Trims Camp with up to 18 inches away from the road.

- High temperatures remain in the 30s and low 40s with low temps in the teens and 20s. Warmest temps are expected to reside in the Middle/Upper Tanana Valley.

- Another round of snow, potentially heavy again in the southern AK Range Sunday through Tuesday with significant accumulations possible. Lighter snow and rain possible in the Interior with minor accumulations possible.

West Coast and Western Interior... - A brief "lull" in the wind speed along the Bering Strait with sustained winds around 15 to 25 mph today, but northeast winds increase tomorrow afternoon and continue to to increase through Saturday. * Northeast wind gusts in St. Lawrence Island by Saturday evening will be as high as 55 mph. Elsewhere along the coast, expect northeast wind gusts around 25 to 45 mph with the weakest being in Norton Sound.

- Steady snow moves into SW AK Saturday night and spreads north/east through Sunday. Blowing snow and low visibility below 1 mile at times is possible in the YK Delta on Sunday. * Snow accumulations from Sunday to Monday may be as high as 6 inches in portions of the Western Interior, especially in higher terrain.

- Similar temperatures are expected today compared to yesterday. A cooling trend arrives on Friday with highs in the teens and 20s from Shungnak to St. Lawrence Island. Highs in the low 30s from Nome to Hooper Bay and mid to upper 30s in the Interior. * Expect a continued cooling trend into Saturday with 20s to near 30 hanging on in the YK Delta, teens and low 20s north of there along the coast and upper 20s to mid 30s in the Interior.

- Wind chills as low as -20F to -30F are possible in the Bering Strait Region Saturday and Sunday as temperatures drop and winds increase.

North Slope and Brooks Range.. - Areas of stratus and fog along the Arctic Coast will persist through Saturday morning but there will be breaks Saturday afternoon.

- Areas of snow move over the Central Brooks Range Friday night and continues through Saturday and into Sunday. * Snow totals around 3 to 7 inches are possible with the heaviest being around Coldfoot/Wiseman and the lightest being in Anaktuvuk/Atigun Pass.

- Light snow then moves to the North Slope with around 1 to 2 inches of snow from Umiat north and east.

- Temperatures remain chilly for the Brooks Range with highs around 0 along the Beaufort Sea Coast, single digits in Atigun/Anaktuvuk Pass, 10 to 20F near Point Hope and 20s to near 30 in the southern Brooks Range. * Low temperatures will be in the single digits and teens below zero from the Brooks Range northward with teens above zero in around Wiseman/Coldfoot.

FORECAST ANALYSIS AND DISCUSSION

At 500mb we currently have a 545 dam ridge north of Siberia, easterly flow with a stalled boundary over the North Slope, westerly flow over the Interior/West Coast and a 580 dam ridge over the east Pacific extending north into the Gulf. To the West over the Bering Sea, there is troughing and a copious amount of shortwave troughs rotating around a 522 dam low over Nunivak Island. All of this is working together to provide an ample amount of cloud cover and scattered rain/snow showers for much of Northern Alaska. As we head through the night, the trough will dig southward allowing for southerly flow into the southern/eastern AK Range. This southerly flow will result upslope snow for the south slopes of the AK Range. The snow will be heavy at times resulting in a snowy and slushy mess after sunrise and before sunset today, tomorrow and Saturday.

Heading into Sunday, a lot of these pieces move around allowing for a low in the Bering to provide a front with snow and wind to the West Coast. There will also be an arctic trough dropping south from the North Pole and this will provide a resurgence of arctic air over the western half of Northern Alaska. Both of these combined will make for strong winds through the Bering Strait and very cold wind chills as low as -30F this weekend. Snow and blowing snow is expected in the YK Delta beginning on Sunday. This snow will traverse northeastward through the day Sunday and into Monday.

The Central and Eastern Interior may get some of this snow and that is one thing we are monitoring. Guidance has been waffling back and forth with where the upper trough from the arctic goes. Current thoughts are that it will be centered near the Chukchi Sea Coast allowing for the flow into the Interior to be southwesterly. This would chinook the Eastern Interior keeping it dry in the Upper Tanana but also bring snow to much of the terrain north of Fairbanks. Snowfall totals are uncertain but several inches of snow are possible Sunday night through Monday, especially in the White Mountains, Dalton Highway Summits and Yukon-Tanana Uplands.

EXTENDED FORECAST DAYS 4-7

To start out the extended time frame, an extensive area of precipitation (mostly snow) will extend from the YK Delta northeast across western portions of the Interior. There is uncertainty on exactly how far east or west this area will be. A majority of model guidance places the band along an axis extending from the YK Delta to near Bettles, although a few outliers extend it in a more northward direction, reaching into the Western Brooks Range. Regardless, in the area of this primary band, liquid-equivalent precipitation could range from 0.2 to 0.5 inches. While the southern portions of this area could see some daytime transition to rain when it is warmest, most precipitation will likely fall as snow. While there is uncertainty on totals in part due to uncertain snow ratios, there is some model support for ratios of 15:1 or higher, which could potentially support over six inches of snow in many areas. Some light snow will also be possible over the North Slope beginning this weekend and running through early next week. By Monday, some of the precipitation in the Western/Central Interior could begin pushing into the Eastern Interior, with scattered snow/rain showers remaining possible through late in the week. There is high uncertainty with the precipitation type and timing as there's the potential for chinook flow over the Interior. It is possible that the Tanana Valley remains dry while just to the north in the higher terrain, it is snowing and accumulating. Current thoughts would lead towards a blend of both. The event should begin mostly dry in the Tanana Valley while snowing north, then as the aforementioned arctic trough drifts east, it would bring steadier snow east into the Central/Eastern Interior Monday into Tuesday. During the midweek timeframe, cold air over Western Alaska could briefly intrude into the central and eastern parts of the state, which could drop highs even in the warmer valleys to near or below freezing.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Winter Weather Advisory for AKZ850. PK...Brisk Wind Advisory for PKZ806-807-811-817-854-856-857. Brisk Wind Advisory for PKZ810. Brisk Wind Advisory for PKZ812. Small Craft Advisory for PKZ816. Heavy Freezing Spray Warning for PKZ816. Brisk Wind Advisory for PKZ851. Brisk Wind Advisory for PKZ858.