textproduct: Fairbanks

..North Slope and Brooks Range

- Light snow showers will continue along the Arctic Coast and Brooks Range through Monday. Snowfall accumulations will generally remain light, with up to half an inch possible along the eastern Arctic Coast, and locally higher totals of 1 to 2 inches at Wainwright.

- Northeast winds gusting up to 35 mph will continue this morning in Atigun and Anaktuvuk Passes, gradually decreasing this afternoon into the evening hours.

- Gusty winds will continue along portions of the Chukchi Sea coast today with gusts up to 55 mph possible along the Lisburne Peninsula. Winds will gradually decrease, shifting farther east by midweek.

- Widespread snowfall is possible along the Arctic Coast and North Slope starting Tuesday with accumulations of 1 to 3 inches possible. Winds are expected to increase along the Beaufort Sea Coast at this time, with gusts potentially approaching 50 mph, bringing blowing snow concerns and reduced visibilities to the Eastern Arctic Coast.

- Temperatures will gradually cool toward seasonal normals throughout the week.

SYNOPSIS

A series of weak disturbances will continue to bring periods of light snow across portions of Northern Alaska this week, while gusty winds continue along the Arctic Coast. Snowfall accumulations will remain light with the highest amounts over the higher terrain of the Interior, Brooks Range, and St. Lawrence Island. Gusty winds along the Arctic Coast will persist due to high pressure north interacting with low pressure to the south. These winds may cause periods of blowing snow and reduced visibility at times. Throughout the week, temperatures will continue to gradually trend downward toward seasonal normals.

SHORT TERM /THROUGH TUESDAY NIGHT/

The overall pattern across Northern Alaska will continue to be characterized by broad troughing aloft south of a strong ridge of high pressure over the Arctic Ocean. Meanwhile, a series of strong surface lows will track eastward across the Gulf of Alaska. This pattern will keep several weak shortwave troughs rotating northwestward across our region around their parent Gulf lows. Associated vorticity maxima will provide periods of upper level lift, supporting scattered snow showers across portions of the Interior and West Coast. While the overall pattern remains fairly progressive, the Arctic ridge will maintain a tight north to south pressure gradient across the Arctic Coast, keeping strong, gusty winds along the coastline, even as the high shifts west to east.

The periodic shortwave energy will favor isolated to scattered snow showers across the Interior and West Coast, with terrain playing a role in providing orographic lift for heavier accumulations. Today, the Dalton Highway Summits and the White Mountains are the greatest area for snowfall amounts across the Central and Eastern Interior as weak disturbances move northwestward from the southeast. Farther west, snow showers remain possible across the Seward Peninsula and east to Galena. The Bering Strait and St. Lawrence Island will see the greatest snowfall accumulations today due to persistent moisture and passing disturbances. Additional snow shower activity will develop across the Tanana Valley, Galena, Huslia, and higher terrain of the White Mountains and Dalton Highway Summits again on Monday as another disturbance moves northwestward through the Interior. However, a relatively dry air mass and limited midlevel moisture will keep snowfall accumulations light.

The coastal wind pattern will be controlled by the position of the Arctic high and the resulting pressure gradient. Stronger winds will initially favor the Chukchi Sea coast and Bering Strait through today before gradually diminishing as the pressure gradient relaxes along the western Arctic Coast. As the Arctic high shifts eastward, the pressure gradient will tighten again along the Beaufort Sea Coast, allowing winds to increase early this week.

Farther north, the more notable evolution will be an increase in precipitation coverage across the North Slope and Arctic Coast Tuesday. Initially, only isolated snow showers are expected as limited forcing and moisture keeps precipitation relatively sparse. However, additional shortwave energy moving north across the Brooks Range will increase lift and moisture transport into the North Slope, allowing snow to become more widespread. The coastal wind pattern will be controlled by the position of the Arctic high and the resulting pressure gradient. Stronger winds will initially favor the Chukchi Sea coast and Bering Strait through today before gradually diminishing as the pressure gradient relaxes along the western Arctic Coast. As the Arctic high shifts eastward, the pressure gradient will tighten again along the Beaufort Sea Coast, allowing winds to increase early this week. The combination of increasing snowfall and stronger winds will bring blowing snow concerns along the Arctic Coast, where a Winter Weather Advisory will likely be needed. Confidence is increasing in this general evolution, although the exact placement of the more persistent snowfall remains uncertain.

Temperatures will gradually cool toward seasonal normals this week as colder air filters into the region beneath the broad upper level trough. Increasing breaks in cloud cover will also allow for more efficient radiational cooling where skies are clear.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

The overall pattern is expected to remain characterized by this broad upper level troughing across most of Alaska, with strong high pressure persisting over the Arctic Ocean and a series of surface lows tracking eastward through the Gulf of Alaska. Ensemble guidance shows good agreement on this large scale pattern, though confidence decreases in the timing and placement of individual disturbances toward the end of the week. Weak shortwaves rotating around the Gulf lows will continue to bring occasional periods of light snow to portions of Northern Alaska through the week. However, increasingly limited moisture and the dominant storm track remaining primarily south of the forecast area should keep precipitation generally light and scattered. As we get closer to the weekend, snow chances become increasingly isolated as the Gulf lows weaken and a much colder, drier air mass continues to move farther into the region. High pressure working through the Aleutian Island Chain on Saturday will allow for a low pressure system to make its way into the Bering Sea, bringing the potential for a rain/snow mix to the YK Delta and West Coast.

Temperatures will trend down toward seasonal normals throughout the week with some areas possibly seeing their first subzero (F) temperatures by the weekend. Current model guidance favors 850 mb temperatures getting as low as -10 to -20 degrees Celsius, which would mark the coldest airmass so far this season. Increasing breaks in cloud cover will also allow for additional overnight cooling, especially in clear areas across the Interior. Gusty winds are expected to persist across the Arctic Coast as the pressure gradient remains tight between the Arctic high and the low pressure to the south, but should gradually lighten by the end of the week to gusts in the 30 mph range. Overall, the pattern favors generally quieter conditions across much of Northern Alaska, with light snow and colder temperatures as the main features of the extended.

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. MARINE...Small Craft Advisory until midnight AKST tonight for PKZ810. Heavy Freezing Spray Warning until 6 AM AKST early this morning for PKZ810-811-814-857-858-860. Gale Warning until 6 AM AKST Monday for PKZ811. Small Craft Advisory until 6 AM AKST Monday for PKZ811-812-817- 857-858. Heavy Freezing Spray Warning from 6 PM this evening to 6 AM AKST Monday for PKZ811. Heavy Freezing Spray Warning until 6 AM AKST Monday for PKZ812- 815. Heavy Freezing Spray Warning from 3 PM this afternoon to 6 AM AKST Monday for PKZ814-861. Small Craft Advisory until 9 AM AKST this morning for PKZ854. Small Craft Advisory until 3 AM AKST Monday for PKZ856. Gale Warning until 6 PM AKST this evening for PKZ857. Gale Warning from 9 PM this evening to midnight AKST tonight for PKZ857. Heavy Freezing Spray Warning from 3 AM to 6 AM AKST Monday for PKZ857>859. Heavy Freezing Spray Warning from midnight tonight to 6 AM AKST Monday for PKZ860. Heavy Freezing Spray Warning until 9 AM AKST this morning for PKZ861.