textproduct: Fairbanks

SYNOPSIS

Cold conditions continue across most of Northern Alaska, with widespread temperatures in the negative teens or colder outside of the Bering Sea region. On the North Slope and at Arctic Village where very cold temperatures combine with winds, wind chills of below 60F but as low as 70F remain possible through Wednesday evening. A system moving into the Bering Sea by tonight will bring unsettled weather to the area, with gusty winds, warming temperatures, and snowfall possible across much of the area through at least the mid-to-late-week time frame.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Very cold and mostly dry conditions will continue across the Interior, as snow chances remain confined to the Upper Tanana Valley and Eastern Alaska Range. A Winter Weather Advisory remains in effect in this corridor through tonight for an additional 1-5" of snow.

- Coldest valleys through midweek will continue to reach down to the 20s/30s below zero with 40s below zero expected for the Yukon Flats up to Arctic Village. Wind chills will be even colder at times.

- Snow chances increase across the Interior and Alaska Range Tuesday into Wednesday, leading to warming temperatures and increased winds. Strongest winds will be through Alaska Range Passes, around Delta Junction, and across higher elevations.

- Snowfall amounts midweek are expected to be around 1-3" with up to 3-6" for southern portions of the Alaska Range Passes.

West Coast and Western Interior...

- Very cold and dry conditions will continue across Western Alaska through Monday, with coldest locations reaching down to the 20s/30s below zero with even colder wind chills. Winds remain breezy along the West Coast and across higher elevations.

- A system moving into the Bering Sea tonight into Tuesday will support an increase in winds, snow chances, and warming temperatures through midweek.

- Winter Storm Watches are now in effect Tuesday through Wednesday night for the Yukon Delta north to the Southern Seward Peninsula and at St. Lawrence Island where the heaviest snow and strongest winds are expected. Gusts will generally peak around 40-50 mph with a broad 2-6" of snow expected.

North Slope and Brooks Range...

- Very cold and dry conditions will continue through midweek, as temperatures reach down to the 30s/40s below zero to around 50 below zero from Toolik Lake to Umiat. Wind chills will be even colder, down to around 50-70 below zero. Extreme Cold Warnings remain in place through at least Wednesday.

- Winds will continue to remain light overall as more moderate winds remain confined to the Western Arctic Coast from Point Lay to Point Hope. Winds will see an increase regionwide Tuesday into Wednesday, with areas of blowing snow and localized blizzard conditions possible.

- Light snow chances will move into the Brooks Range and North Slope Wednesday into Thursday.

FORECAST ANALYSIS AND DISCUSSION

Generally clear and cold conditions continue across most of the Interior and North Slope, with cold troughing aloft over the Canadian Archipelago extending southwest across the northeastern half of so of Mainland Alaska. Parts of the eastern North Slope and Arctic Village are experiencing very cold temperatures near or below 30F with variably windy conditions, yielding wind chills below 60F. For these conditions, an Extreme Cold Warning has been issued for wind chills as cold as 70F. In the Interior, with the exception of southeastern areas, temperatures in the teens and 20s to near 30 below zero are common, with somewhat warmer temperatures in the negative single digits along the West Coast. Snowfall, at times moderate to heavy, will likewise continue across the southeastern Interior, where multiple inches of snow (possibly exceeding 6 inches of total accumulation in spots) will be possible through Tuesday morning. A compact ~970 mb low over the Central Bering Sea will bring some increased easterly winds today in the northern Bering but will quickly swing back to the west and out of the area, only bringing brief light snow to areas near/south of Hooper Bay/Chevak.

A stronger low will cross the Aleutians into the southern Bering Sea late Monday and begin impacting the area Tuesday morning. The first impacts will be along the occluded front on the leading edge, with a broad area of easterly gale-force winds spreading across the northern Bering and adjacent coastal areas. Some areas on the Seward Peninsula and St. Lawrence Island as well as at Unalakleet could see winds gust upwards of 50 mph. The system will first begin bringing snowfall to southwestern Alaska Tuesday morning and lasting through the day before spreading into much of the remainder of the state from Tuesday evening/night onward. Winds will also increase across inland areas, especially at elevation, which could combine with pre-existing cold temperatures to yield cold wind chills. Blowing snow in spots is also a possibility, including across the Western Arctic Coast where blizzard conditions already recently occurred. Temperatures will begin to moderate in the Interior Tuesday into Wednesday as the coldest air mass (and corresponding trough aloft) gets shunted back into the North Slope.

As snow pushes into the Central/Eastern Interior on Wednesday, snowfall rates for the system will generally fall off (even in Western Alaska) and become lighter, but there will still be the potential for up to a few inches of snow in these areas with efficient snowfall possible at times. As the trough over Northern Alaska gets pushed off to the north, southerly winds will begin to take hold across the Alaska Range, which could result in some level of a downsloping/drying effect on the immediate north/lee side of the mountains relative to areas farther north. There could also be periods of gap winds blowing through the Alaska Range passes. Conversely, higher snow totals of potentially upwards of six inches will be possible on the southern/upwind side of the Alaska Range where upsloping / orographically-induced snow is maximized. Regardless, model prognosis generally supports snow in the Eastern Interior diminishing by late Wednesday into Thursday.

The system's landfall is most likely during the late Wednesday into Thursday time frame, with uncertainty on the exact low track / point of landfall. Most ensemble guidance supports a landfall somewhere between Nunivak Island and Bristol Bay, but there is agreement in the easterly offshore winds during the initial phase of the storm's approach becoming northerly (including along the Western Arctic Coast, where blowing snow could be a concern) by the early-to-mid Wednesday time frame and then briefly turning onshore/westerly by late Thursday morning.

EXTENDED FORECAST DAYS 4-7

Thursday through Sunday. By late Thursday morning, strong northerly winds through the Bering Strait will start turning to the northwest/west, allowing for a short period of possible onshore winds. As the storm moves inland/out of the area, these winds will slacken by Thursday night in the Bering Sea but continue on the Western Arctic Coast. With cyclogenesis occurring just northwest of Cape Lisburne on the east side of a Siberian trough, northerly winds will become northeasterly or easterly around the new low and could continue into Friday, potentially yielding blowing snow and/or blizzard conditions. A trough/cold front running along the West Coast will also push inland late Thursday into Friday and could bring some additional light snow chances to inland areas.

Late Friday into Saturday, a weaker but wet low will move into the eastern Bering Sea. As it pushes east, there will be the potential for an extensive area of snow across most of the Interior, although the track could make a significant difference on totals. A more southerly track could result in a drier Interior and more of the moisture gets wrung out of the atmosphere in Western/Southwestern Alaska, while a more northerly track could permit more unobstructed flow and allow for higher snow totals to make it farther east. While there is high uncertainty on the exact storm track, model prognosis generally supports higher totals on the Bering Sea coast and in the southwestern Interior.

Moving into early next week, model/ensemble confidence is low, with models generally supporting at least a brief return to cold conditions in the Interior, but some quickly push the cold air out with a continuation of the unsettled weather pattern with additional Bering Sea lows.

Coastal Hazard Potential Days 3 and 4... As a low moves into the eastern Bering Sea on Tuesday (Day 2), it will bring with it a fairly wide area of gale-force winds. Given the likely storm track to the south of Nunivak Island, these winds should remain largely easterly to southeasterly and offshore. By Wednesday afternoon and evening, winds are likely to turn more to the north, which could bring winds alongshore in parts of the YK Delta and onshore over northern St. Lawrence Island. These areas are generally heavily ice-covered, which should limit the overall flooding potential, but some water rises through cracks in the ice at Hooper Bay are a possibility.

AFG WATCHES/WARNINGS/ADVISORIES

AK...Extreme Cold Warning for AKZ801>810. Extreme Cold Warning for AKZ811. Winter Storm Watch for AKZ820>823. Winter Storm Watch for AKZ824>827. Cold Weather Advisory for AKZ833. Winter Weather Advisory for AKZ836. PK...Brisk Wind Advisory for PKZ801>803-805-811-812-850-852-853-857- 858. Brisk Wind Advisory for PKZ804-807-856. Brisk Wind Advisory for PKZ806. Gale Warning for PKZ816. Gale Warning for PKZ817. Gale Warning for PKZ851. Gale Warning for PKZ854.