textproduct: Fairbanks

SYNOPSIS

An extended period of well below normal temperatures continues into the first week of March for a majority of Northern Alaska. High pressure at the surface keeps this arctic airmass in place with daily morning lows at or below -40F for the Interior. Areas right along the coast in Western Alaska may remain somewhat milder as the core of the arctic airmass shifts east; however still expect temperatures remaining near or below zero into next week. While the majority of the region remains cold and dry, focus shifts to the Northeast Arctic Coast where a series of fronts will bring an extended period of blizzard conditions beginning Friday. This initial front may increase high clouds for the eastern half of Alaska during the day Saturday, briefly moderating temperatures. Watching the Brooks Range passes this weekend for potentially hazardous wind chills below around -60F as northerly winds increase with the frontal passage. Reinforcing shots of arctic air with these incoming fronts keeps the core of the arctic air across the Eastern half of the state through almost the middle of next week.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Blowing and drifting snow continues to reduce visibility and lead to treacherous travel conditions for the Richardson Hwy near Isabel Pass.

- Anomalous and deep cold for late February/early March continues into the weekend. Interior valleys will drop into the -30s and -40s with hill tops above 1500ft dropping into -20s to 30s for morning lows each day. This is 30+ degrees below normal!

- High temperatures rebound each afternoon to -10s.

West Coast and Western Interior...

- Anomalous and deep cold for late February/early March continues into the weekend. Low will reach the -20s to -30s below along the coast, -30s and -40s in Interior Valleys and -15F to -30F below above 1500ft.

- High temperatures rebound in the afternoons to single digits below zero along the coast and around -10F to -20F below zero in the Interior.

- Cold air will begin to be eroded away this weekend but temperatures will remain around 20 to 30 degrees below normal.

North Slope and Brooks Range...

- Blizzard Warnings are in effect for the NE Arctic Coast with conditions deteriorating by Friday Morning. Expect gusts up to 50 mph in Nuiqsut and Deadhorse, and 65 mph in Point Thomson and Kaktovik.

- Winds increase through the Brooks Range this weekend, blowing snow and dangerously cold wind chills are possible. Cold Weather Advisories have been issued for the Brooks Range Passes Saturday into Sunday.

- Temperatures remain cold, around 15 to 30 degrees below normal through Saturday, with milder temperatures possible on Sunday.

FORECAST ANALYSIS AND DISCUSSION

A deep Arctic airmass remains over Alaska with widespread temperatures at or below -40F earlier this morning. To give an idea how cold this airmass is, using the SPC Sounding Climatology webpage, the coldest ever 850mb temperature on the morning of February 26th is -31.2C... Fairbanks 00z and 12Z soundings from the past day had 850mb temperatures of -28C to -30C! Despite it being late in season and the sun angle quickly rising, these near record low level temperatures and a strong surface high will result in rapid temperature drops each night into the -30F to -45F range, with the potential for a few -50F reports in the coldest interior valleys. Record or near record cold temperatures are possible, but record temperatures are currently in the -50s for the next few days, which most likely won't occur in Fairbanks thanks to increased surface heating as the sun rises. Nonetheless, widespread -30s and -40s low temperatures are expected through the weekend.

Outside of the arctic air, focus shifts to the NE Arctic Coast where numerous fronts coming in from the north will result in an extended period of blizzard conditions. Went ahead and issued Blizzard Warnings for the Northeast Arctic Coast beginning Friday morning and persisting into the weekend as numerous fronts rotate around an intense 465dm upper low over the Canadian Arctic Archipelago. The first front arrives Friday morning with a 50-60 kt barrier jet developing along the NE Arctic Coast. This is a classic set up for an extended period of Blizzard Conditions in this region. Issued warnings as far west as Nuiqsut, where Blizzard conditions are expected Friday into Saturday. Further east toward Point Thompson and Barter Island, Blizzard conditions may persist through Monday March 2nd as additional fronts rotate in from the north and impact the coast. Lower confidence exists for Deadhorse and points west for Blizzard Conditions the latter half of the weekend as the strongest barrier jet may remain to the east.

As these polar fronts shift southward, a few impacts may be seen across the Brooks Range and potentially into the Eastern Interior. Low and mid level pressure gradient builds up on the north side of the Brooks Range by Friday night, resulting in windy conditions at Anaktuvuk and Atigun Pass with northerly gusts to 40 mph through Monday night. Wind chill values colder than 60 below zero are possible from the Brooks Range to the Coast. Cold Weather Advisories have been issued for the Eastern Brooks Range including Atigun pass Saturday into Sunday.

Guidance has been consistent in showing upper level moisture associated with this polar front making its way southward into the Central and Eastern Interior on Saturday. Depending on the timing of arrival of these higher clouds, some areas in the Eastern Interior may see quick temperature rises from the -40s to -20s. While there is high confidence in the extended stretch of cold weather, Saturday's temperature forecast has the lowest confidence mainly due to the incoming clouds during the day. For now, keeping lows in the Central and Eastern Interior in the -40s while highs reach the -10s to -20s, but do want to mention that high temperatures could potentially exceed guidance if these clouds are thick enough. There is higher confidence that the interior will clear out again Saturday night behind the front with its reinforcing shot of colder air with another night of widespread -40s.

The West Coast and Western Interior remains cold as well, but temperatures likely won't reach record values. Temperatures look to moderate on Sunday and Monday as milder air from a ridge over the Western Bering moves in. This may also tighten a pressure gradient bringing stronger northerly winds, especially through the Bering Strait.

Otherwise, no precipitation is expected for most of the Interior or West Coast for the foreseeable future.

EXTENDED FORECAST DAYS 4-7

The extended stretch of well below normal temperatures continues into the first week of March. While the upper trough over the state pushes into Northern Canada and weakens, a secondary upper low over the Canadian Arctic Archipelago retrogrades closer to the state, bringing a reinforcing shot of arctic air to Northern and Eastern Alaska Sunday through mid next week. The core of the arctic airmass with 850mb temperatures below -30C, becomes centered over Northwest Canada and Eastern Alaska this weekend and Monday. While the majority of the state will remain well below normal, coldest temperatures remain in the Central and Eastern Interior while temperatures moderate somewhat in Western Alaska with highs nearing zero and lows still in the teens to 20s below zero. Eastern Interior valleys likely have several more days with low temperatures at or below -40F, potentially lasting into the first week of March. Still expecting large diurnal ranges in this clear, cold, and dry airmass as the increasing sun angle allows for afternoon temperature rises into the negative single digits and teens.

The NE Arctic coast will be dealing with an extended period of blizzard conditions through at least Monday as several fronts rotate around a deep low in the Canadian Arctic. Blizzard Warnings from Point Thompson to Barter Island go through Monday morning with conditions expecting to improve into Tuesday. Currently the Blizzard Warning for Deadhorse and Nuiqsut go through Saturday morning with a lull in the worst conditions expected through the day. There is the potential for addition blizzard or near blizzard conditions for this area and points west along the Arctic Coast Sunday into Monday, but confidence is lower if actually blizzard conditions will be met. Nonetheless, additional periods of accumulating snow and blowing snow are expected into early next week as additional fronts rotate south into the coast, mainly east of Utqiagvik.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Cold Weather Advisory for AKZ848-850-851. Blizzard Warning for AKZ804. Blizzard Warning for AKZ805. PK...Brisk Wind Advisory for PKZ813. Gale Warning for PKZ814-860. Gale Warning for PKZ815-861. Brisk Wind Advisory for PKZ859.