textproduct: Fairbanks

SYNOPSIS

A large storm system enters the Bering Sea today and slowly moves northeast through Wednesday. As it approaches winds increase across the West Coast ahead of a front bringing areas of light to moderate snowfall to much of the West Coast and Western Interior. Cold temperatures across the North Slope and Interior warm as the storm brings warmer air north. Periods of blizzard conditions are expected across the West Coast from the Bering Strait south to the YK Delta. The storm weakens rapidly Wednesday night into Thursday. Another, weaker, but wetter system moves into the Bering Sea late this week bringing more widespread snowfall to much of the region this weekend.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Very cold and mostly dry conditions will continue across the Interior through Tuesday morning, 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 southerly through the Alaska Range Passes, easterly around Delta Junction, and easterly/northeasterly across the White Mountains and Dalton Highway Summits.

- Snowfall amounts Tuesday through Thursday are expected to be around 1-3" with up to 3-7" for southern portions of the Alaska Range Passes. A winter weather advisory has been issued for 4 to 8 inches of snow

West Coast and Western Interior...

- Very cold and dry conditions continue across Western Alaska through Monday, with coldest locations reaching down to the 20s/30s below zero and colder wind chills possible. Winds remain breezy along the West Coast and across higher elevations. The coldest conditions are expected in valleys with light to no wind.

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

- Strong easterly winds gusting up to 55 mph expected Tuesday ahead of the first front of snow approaching from the south Tuesday afternoon through Wednesday. The strongest winds are expected along the coast from the Seward Peninsula south. Winds shift northerly Wednesday increasing through the Bering Strait and decreasing along the Eastern Norton Sound.

- A front extending from the storm brings a wave of new snow across the West Coast from the south to the north Tuesday through Thursday. 2 to 7 inches of snow is expected with the highest amounts expected to the southwest and along south facing slopes along the Southern Seward Peninsula, Lower Yukon, and YK Delta regions. Relatively lighter amounts of 2 to 4 inches are expected for most of the rest of the West Coast and Western Interior.

- Blizzard warnings have been issued for the Lower Yukon, Yukon Delta, Eastern Norton Sound Coast, Bering Strait Coast, Diomede, and St. Lawrence Island. Winter Weather Advisories have been issued for the Southern Seward Peninsula and Interior Seward Peninsula for gusty winds, moderate to heavy snowfall and periods of blowing snow.

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 western portions of the Brooks Range and North Slope Wednesday into Thursday. Total snow accumulations of up to an inch along the North Slope and 1 to 3 inches in the Brooks Range.

FORECAST ANALYSIS AND DISCUSSION

For Monday through Thursday. At the start of the forecast period Monday, a cold air mass with 850 millibar temperatures between -20C to -30C sits over northeastern Alaska and a strong 948 millibar storm enters the Bering Sea. This storm is quickly occluding cutting it off from much of the warm, moist air that has been fueling it which will cause the storm to slowly weaken as it spins over the Bering Sea Tuesday and Wednesday. As the storm meanders north the pressure gradient along the West Coast increases causing easterly winds to ramp up especially from the Seward Peninsula south. Localized Blizzard conditions are possible with these strong winds even ahead of the approaching occluded front. Once the front reaches the Yukon Delta Tuesday evening falling snow will further contribute to the poor conditions. Winds weaken as the front approaches and eventually shift more northerly Wednesday as the storm begins to move east. Another storm moving through the North Pacific towards the Gulf of Alaska drags the Bering Sea storm east while robbing it of much of its strength Wednesday evening and overnight. The storm rapidly weakens late Wednesday through early Thursday. As the front moves further north it pushes against the cold air mass across the North Slope and brings warmer weather to much of the area.

EXTENDED FORECAST DAYS 4-7

For Thursday night through Sunday. Northerly winds through the Bering Strait decrease going into Thursday evening, but are expected to persist along the western Arctic Coast through Friday morning out of the northeast. These stronger winds have the potential to cause some mild to moderate blowing snow conditions, but will likely be short lived. As the upper level ridge situated to our west briefly weakens, a cold front is able to make a quick push inland late Thursday into Friday, creating an additional chance for some light snowfall across the western Interior and Brooks Range. A warm and wet low moves into the eastern Bering Sea late Friday into Saturday, raising temperatures back up into the single digits and teens above zero for much of northern Alaska south of the Brooks Range. With this system, we're expecting to see another wide swath of snowfall return to the West Coast and Interior, with the highest amounts across the Kuskokwim Delta and Alaska Range. Exact snowfall totals are still yet to be determined since they're largely dependent on which track the low ends up taking. For now, we have moderate confidence in a snowier weather pattern for much of northern Alaska going into this weekend. Model confidence is pretty low going into next week, but generally suggests a return of cold and dry weather, with some occasional embedded disturbances out in the Bering Sea.

Coastal Hazard Potential... As a low moves into the eastern Bering Sea on Tuesday, 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 for areas from Hooper Bay north. By Wednesday afternoon and evening, winds shift more to the north, which could bring winds alongshore from the Yukon Delta to Hooper Bay 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. Wind Advisory for AKZ849. Winter Weather Advisory for AKZ850. Blizzard Warning for AKZ820-821. Winter Weather Advisory for AKZ822-823. Blizzard Warning for AKZ824>827. Winter Weather Advisory for AKZ832. Cold Weather Advisory for AKZ833. Winter Weather Advisory for AKZ836. PK...Gale Warning for PKZ801. Gale Warning for PKZ802-803-850-852-853. Gale Warning for PKZ804>807-856. Brisk Wind Advisory for PKZ808. Brisk Wind Advisory for PKZ809-855. Brisk Wind Advisory for PKZ811-812-857-858. Gale Warning for PKZ816-817. Storm Warning for PKZ851. Storm Warning for PKZ854.