textproduct: Fairbanks

SYNOPSIS

A strong storm in the Bering Sea is producing strong easterly winds across the West Coast and is extending a snow producing front across Southwestern Alaska. This front continues north and brings warmer weather to much of the Interior as it moves north through early Thursday. Cold conditions will continue along much of the North Slope where temperatures warm slowly through the end of the week. The storm weakens rapidly late Wednesday through Thursday. Another system moves into the Bering Sea Thursday into Friday that is expected to be much weaker, but wetter. Winds are not expected to be much of a hazard with this next system, but more widespread areas of moderate to potentially heavy snow are expected across the West Coast and most of the Interior this weekend.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Cold and dry conditions Tuesday morning Cloud cover and chances for snow will return by this evening. Temperatures are expected to warm drastically with the arrival of cloud cover.

- With the arrival of the warm front, snow chances and stronger winds will begin this afternoon. 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 across much of the Eastern Interior are expected to be around 1"-3" with up to 3"-5" in Denali Park and south to Cantwell. A winter weather advisory has been issued for Isabell Pass, with upwards of 8" of snow expected.

- Another system will begin impacting the Interior this weekend (Saturday), however we are expecting this system to be weaker and contain more moisture, leading to higher snowfall totals. There is still some uncertainty with this system.

West Coast and Western Interior... - Strong easterly winds gusting up to 55 mph expected Wednesday ahead of the first front of snow approaching from the south this morning and 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 along St. Lawrence Island, and decreasing along the Eastern Norton Sound, Yukon Delta, and Lower Yukon.

- 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"-7" 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"-4" 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 gusty winds, moderate to heavy snowfall and periods of blowing snow along the Southern Seward Peninsula and within the Interior Seward Peninsula.

- Another system will begin impacting the West Coast at the end of this week (Friday), however we are expecting this system to be weaker and contain more moisture, leading to higher snowfall totals. There is still some uncertainty with this system. Coastal hazards are not expected for this system.

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.

- Lighter winds increase regionwide Tuesday evening into Wednesday, with areas of blowing snow and localized blizzard conditions possible. The strongest winds are expected along the Western Arctic Coast. Winter Weather Advisories have been issued for blowing snow along the Arctic Coast east of Point Lay. A Blizzard Warning has been issued for the Western Arctic Coast including Point Hope and Point Lay.

- 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

At the start of the forecast period Tuesday, a strong 948 millibar low in the Bering Sea has caused strong easterly winds across much of the West Coast and is extending an occluded front north bringing snow across much of the West Coast. This storm stalls in the Bering Sea through most of Wednesday slowly weakening after the occluded front cuts off its warm, moist air. Another low moving through the North Pacific into the Gulf of Alaska Wednesday rapidly strengthens as it effectively hijacks much of the support that had been fueling the Bering Sea low. The Bering Sea low drags east and rapidly weakens causing winds to shift to the north along the West Coast late Wednesday. Along the northernmost part of the system some cyclogenesis allows part of the occluded front to sustain itself over the Western Arctic Coast as a much weaker system. This will bring light snow to the Western Arctic and sustain the weakening winds along the North Slope through at least Thursday. Should this smaller system prove resilient some snow may reach east into the Central Brooks Range and eastern portions of the Arctic Coast, but by that point snowfall will be very light and winds have waned. Another, weaker, low enters the Western Bering Sea late Thursday and brings significantly lighter winds and more widespread snowfall to the West Coast by Friday.

EXTENDED FORECAST DAYS 4-7

A new system will begin to move into the Bering Sea and towards the West Coast on Friday. We are currently expecting this system to be weaker, but contain more moisture than the current storm. A weaker system means winds along the West Coast will range from 25 to 35 mph. More moisture will mean heavier snowfall, especially for communities along the West Coast, potentially leading to periods of reduced visibility. Snow is expected to begin reaching the Interior by Saturday morning. However, models are not in agreement in regards to snow amount. Snow totals will depend on how much moisture makes it to the Interior. Surface winds could strengthen as high as 25 mph for parts of the Interior as the warm front passes. Since this system is associated with more moisture in combination with weak west-southwest flow aloft, downsloping is not a big concern for the Tanana Valley.

Coastal Hazard Potential... Mostly easterly winds from a storm in the Bering Sea are causing gale force marine winds and strong offshore flow. 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. Blizzard Warning for AKZ801. Winter Weather Advisory for AKZ802>805. 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. PK...Brisk Wind Advisory for PKZ801-809-855. Gale Warning for PKZ802-804. Gale Warning for PKZ803. Gale Warning for PKZ805-852-853. Gale Warning for PKZ806-807-856. Brisk Wind Advisory for PKZ808. Brisk Wind Advisory for PKZ810. Gale Warning for PKZ811-857. Gale Warning for PKZ812. Brisk Wind Advisory for PKZ813-859. Brisk Wind Advisory for PKZ814-815-860-861. Storm Warning for PKZ816. Storm Warning for PKZ817. Gale Warning for PKZ850. Storm Warning for PKZ851. Storm Warning for PKZ854. Gale Warning for PKZ858.