textproduct: Fairbanks

SYNOPSIS

A warm front will bring accumulating snow across most of the area south of the Brooks Range Tuesday afternoon through Wednesday. Accumulations will generally be a trace to 4 inches, though up to 6 inches are possible from Eagle to Eagle Summit and in the eastern portions of the White Mountains. Areas of blowing snow along with east winds and wind chills as cold as -50 F continue along the Arctic Coast. Northeast winds 15-25 mph over higher terrain in the Interior will intermittently mix to valleys floors through Wednesday, but aviators should be aware that low level wind shear will be a concern especially ahead of the main warm front.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- High temperatures will remain around 0 to 10 above through the week with lows between 0 and 10 below.

- A warm front will bring snow accumulations of a trace to 4 inches across the whole area beginning this afternoon in the eastern Interior and spreading northwest through Wednesday. Highest amounts may exceed 6 inches near Eagle Summit. Fairbanks can expect 1-3 inches.

- Winter Weather Advisories have been issued for the Dalton, Elliott, and Steese Highway Summits from Tuesday through Wednesday night for strong winds combined with blowing and falling snow.

- Intermittent E/NE winds persist through the week across the Interior Valleys. With winds mixing to the surface at times and other times staying just above, expect some low level wind shear at terminals including Galena, Tanana, Bettles, and McGrath as well as other sites. TAFs will remain updated on this as PIREPs allow.

West Coast and Western Interior...

- Northeast winds 15-25 mph with higher gusts will continue across Western Alaska today, with the strongest winds expected along the West Coast and across the higher elevations. Gusty winds may lead to areas of blowing snow at times through the end of the week.

- A warming trend begins Wednesday with highs into the 10s/20s above zero. Chevak and Hooper Bay may approach freezing on Wednesday as warm air surges northward with a low from the North Pacific.

- Light snow chances will increase across Western Alaska Wednesday into Thursday, but only light accumulations are expected.

- Intermittent E/NE winds persist through the week across the Interior Valleys. With winds mixing to the surface at times and other times staying just above, expect some low level wind shear at terminals including Galena, Tanana, Bettles, and McGrath as well as other sites. TAFs will remain updated on this as PIREPs allow.

North Slope and Brooks Range...

- Temperatures will be mainly in the -20F to -30F range this week with even colder wind chills down to -40 to -50F. Temperatures across the Arctic Plain may dip into the -40s at times through Wednesday, and then again over the weekend.

- East winds across the Arctic Coast continue through Thursday with areas of blowing snow at times. Winter Weather Advisories and Blizzard Warnings have been cancelled as visibility has improved. Winds are not anticipated to reach speeds capable of resuspending the blown snow.

- North winds through Brooks Range passes will remain strong through the week as the pressure gradient stacks up across the Brooks Range. Expect wind speeds 20-30 mph with gusts to 40 to 45 mph through Atigun and Anaktuvuk Passes, and higher winds to the west. Wind chills near -40 F accompany these winds.

FORECAST ANALYSIS AND DISCUSSION

A very strong and persistent Arctic high remains just north of Wrangel Island, with a peak surface pressure of 1044 mb. This will keep east winds along the Arctic coast through the week with areas of blowing snow and low visibility. A 967 mb low just east of Kodiak will move through Kennedy Entrance and weaken, but its associated warm front will bring a trace to 4 inches of snow across most of the Interior through Wednesday. Models have trended back to the north and east and have come into better agreement on the location and amounts of the heaviest snowfall, which looks to be 4-8 inches from Eagle to Eagle Summit and north into the eastern portion of the White Mountains. The GFS continues to be lighter on totals than other models, but high resolution models are in good agreement with the NAM and other global models. Cold air advection from the northeast as the warm front runs into a very cold airmass will yield deep dendritic growth zones and snow ratios near 30:1 around Eagle Summit. The snow will be light and fluffy and want to blow around in the wind, hence a Winter Weather Advisory is in effect for Dalton, Elliott, and Steese Highway summits. Further south, expect snow to be less fluffy but still accumulate efficiently. Accumulations elsewhere will be a trace to 4 inches for nearly the whole forecast area south of the Brooks Range.

After this warm front moves through, weak ridging will build back over the eastern Interior while a cold air mass settles over the North Slope. Snow showers will persist along the deformation band between these in the Northern Interior. Temperatures along the North Slope will likely be near -40 F by Saturday. Wind chills on Wednesday may approach -60 F.

EXTENDED FORECAST DAYS 4-7

More active weather will develop late in the weekend moving into early next week as a series of strong low pressure systems move into the southern Bering Sea. At this time, probabilities are very low in the storm track shifting north of Nunivak Island, which would keep impacts from these storm systems south of the forecast area boundary. However, these lows will bring precipitation to the West Coast and likely to parts of the Interior as well. Periods of Chinook conditions will develop in the southern Interior, though the cold airmass over the North Slope will persist north of the Brooks Range. East winds continue along the Arctic Coast as high pressure in the Arctic persists.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Winter Weather Advisory for AKZ832-834. PK...Brisk Wind Advisory for PKZ801. Brisk Wind Advisory for PKZ802-803-806-807-809-810-850-853. Gale Warning for PKZ804. Gale Warning for PKZ805. Brisk Wind Advisory for PKZ808-855. Gale Warning for PKZ811-812-856>858. Brisk Wind Advisory for PKZ813. Gale Warning for PKZ816-851. Gale Warning for PKZ817-854. Gale Warning for PKZ852. Brisk Wind Advisory for PKZ859.