textproduct: Fairbanks

SYNOPSIS

Fairly calm yet cold conditions today across most of Alaska with a few exceptions along the coast where windy conditions have led to periods of blowing snow. Northerly winds are beginning to pick up through the Bering Strait this afternoon and should continue increasing tonight. A Winter Weather Advisory has been issued for the Western Seward Peninsula and Diomede through Sunday morning for the potential for blowing snow reducing visibility to less than a half mile at times. Similar situation the rest of this evening for the Eastern Arctic Coast where winds and blowing snow are reducing visibility as well. Cold and calm conditions throughout the Interior today as high temperatures are reaching the single digits above and below zero. Light snow showers and flurries from this morning have shifted east, mainly toward the Alaska/Canadian border and Tanana Valley. This similar weather pattern stays largely the same for the next week as near record cold persists for the Interior while cold and windy conditions with blowing snow at times are expected along the west coast and eastern Arctic Coast. Periods of snow expected for the Alaska range and Tanana Valley Sunday through early next week as a system sets up in the Gulf. A Winter Storm Watch for blowing snow and potentially blizzard conditions has been issued for the southern slopes and passes of the Alaska Range Sunday through early Wednesday.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Well below normal to near record cold temperatures for this time of year continue into next week. Despite moderating temperatures this weekend, expect lows once again in the 30s and 40s next week.

- North winds increase through the Alaska Range passes Sunday through mid next week. A Winter Storm Watch for near blizzard conditions has been issued for the Alaska range passes.

- Mainly dry for the majority of the Interior, with the exception of the Upper Tanana Valley and far eastern Interior where snow chances increase Sunday into early next week.

West Coast and Western Interior...

- Northerly winds increase through the Bering Strait tonight leading to periods of blowing snow. A Winter Weather Advisory has ben issued for portions of the Seward Peninsula for visibility as low as 1/2 mile at times.

- Relatively milder conditions continue through this weekend, but below normal temperatures return next week with double digit subzero lows.

- Another period of high winds and blowing snow possible for the Bering Strait and West Coast mid to late next week

North Slope and Brooks Range...

- Blowing snow and strong winds for the eastern Arctic Coast today should slowly diminish tonight

- Light snow and blowing snow likely Sunday, especially on the northern slopes of the Brooks Range. Accumulations will be minimal

- Multiple rounds of light snow, blowing snow, and gusty winds for the Arctic Coast most of next week. Near blizzard conditions at times from Deadhorse eastward to the Canadian border.

FORECAST ANALYSIS AND DISCUSSION

Very similar day to day forecast over the next week as the pattern remains relatively unchanged, featuring well below normal temperatures for the Interior and windy conditions along the coasts. Deep troughing will be persistent over Alaska through the end of the month while a strong area of high pressure remains in place over eastern Siberia and the Bering. This pattern keeps northerly flow and an anomalously strong arctic airmass over Alaska while numerous shortwaves from the high arctic dive into the state. A strong upper low develops in the Gulf of Alaska this weekend and remains in place through the week, increasing northerly winds through the Alaska Range and increasing snow chances at times for the far southeast Interior.

First item to focus on will be the snow and wind threat for the Alaska Range and Southeast Interior. As mentioned above, a developing upper low in the Gulf of Alaska this weekend, increasing upper level moisture advection into the far eastern portions of the state. Closer to the surface, the northerly pressure gradient tightens along the Alaska range, resulting in increasing northerly winds beginning Sunday. At the same time, the Arctic airmass strengthens for the interior, further increasing the gradient along the mountains. Guidance shows enough moisture wrapping around the upper low Sunday through Tuesday along with numerous waves of energy resulting in snow chances for the far eastern Interior, Upper Tanana Valley, and Alaska Range. Accumulations will overall be fairly minor with a couple inches likely at lower elevations. Issued a Winter Storm Watch for possible blizzard conditions from blowing snow for the Alaska Range passes Sunday through Wednesday morning. Thinking winds and snowfall elsehwere in the SE Interior should be light enough to stay under warning or advisory criteria; however will have to watch winds through Fortymile Country and the White Mountains as well as blowing snow and reduced visibility may still be an issue at higher elevations.

For the Arctic Coast, numerous shortwaves and surface fronts impact the region today through the rest of the next week keeping the threat for windy conditions and blowing snow in the forecast. Blowing snow and visibility at or below a half mile have been observed along the eastern Arctic Coast today, however expect conditions to somewhat diminish tomorrow as winds slightly decrease. Another round of light snow is expected for the North Slope on Sunday as the next in a series of shortwaves moves through, setting the stage for more blowing snow by Monday. The pattern for the Arctic will be similar each day with higher pressure along the Brooks Range and numerous waves rotating around a polar low increasing the westerly pressure gradient and snowfall chances. Expect another round of near blizzard conditions for the Arctic Coast Monday through Wednesday. As confidence increases, may need Winter Storm Watches for blizzard conditions for Deadhorse and points east for this timeframe where the worst conditions will likely occur.

Across the West Coast, cold and windy conditions persist as numerous shortwaves drop down through the Bering Strait. Northerly winds ramp up tonight with the passing of the first system. Blowing snow may reduce visibility for the Seward Peninsula and areas along the west coast prone to strong northwesterly winds. This round should peak overnight tonight for the Bering Strait, then shift east and weaken during the day Sunday. Northerly flow persist along the west coast and western interior into early next week with isolated periods of blowing snow possible, mainly for the northern Seward and Baldwin Peninsulas. Will also be watching the Northerly pressure gradient set up across the Central and Western Brooks Range Sunday through Tuesday as well with the threat increasing for near blizzard conditions from blowing snow.

For the Interior, dry and cold conditions continue this weekend and into early next week. As a low sets up in the Gulf and additional waves of energy drop south out of the Arctic, reinforcing shots of colder air will strengthen the arctic airmass in place with guidance showing 850mb temperatures below -30C once again! According to the SPC Climatology page, this airmass has the potential to be break record not only at the surface, but for low to mid level temperatures too. This anomalously strong and deep arctic airmass engulfs the entire state through much of next week with daily lows in the Interior in the -20s to -40s. Will have to watch how widespread clouds are across the Southeast Interior and North Slope as clouds should moderate overnight lows somewhat. Areas that clear out in the Central Interior and West have the best chance at breaking daily low temperature records through the week.

EXTENDED FORECAST DAYS 4-7

Similar weather pattern continues into the extended range period. Watching for another, longer lasting round of strong northerly winds through the Bering and along the West Coast mid to late next week as the pressure gradient further tightens with shortwaves dropping out of the Arctic. Also watching the Eastern Arctic Coast for the latter half of next week and into the following weekend as longer range guidance has been consistently showing the chance for high winds over 60 mph and blizzard conditions. While this is nearly a week out, confidence is fairly high in this type of pattern. Deadhorse to Point Thomson to Barter Island will likely experience the worst conditions, but lower confidence exists in the western extent of a possible multi-day near blizzard event.

As mentioned above, a near record cold airmass for this time of year engulfs the state and stays in place for the entire week. The Central and Western Interior have the best chance at clearing out next week with daily lows in the -20s to -40s once again. The ECMWF Extreme Forecast Index highlights nearly all of Alaska for anomalously cold conditions Monday through Friday, further raising forecast confidence.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Winter Storm Watch for AKZ848-850. Winter Weather Advisory for AKZ820-821. Winter Weather Advisory for AKZ804-805. PK...Brisk Wind Advisory for PKZ805. Brisk Wind Advisory for PKZ806-807. Brisk Wind Advisory for PKZ814-815-860-861. Brisk Wind Advisory for PKZ816-850. Brisk Wind Advisory for PKZ817-851. Brisk Wind Advisory for PKZ853. Brisk Wind Advisory for PKZ854. Brisk Wind Advisory for PKZ856.