textproduct: Fairbanks

SYNOPSIS

Cold weather continues across most of Eastern Alaska, but that will continue to change throughout the day and into the weekend as a low moves off of Siberia and transitions over the region. The low will shift east and move along the Arctic coast from west to east, bringing widespread snowfall of at least an inch with much warmer temperatures to most of Alaska north of the AK Range. On the North Slope, winds will increase significantly today as the low moves in, which could result in blowing snow and reduced visibilities at times, especially where they combine with falling snow. There may also be ground blizzards at times through Anaktuvuk Pass once winds increase through the gap out of the south, and for tomorrow morning through Sunday morning along the Northeast Coast, mainly from Prudhoe Bay to Kaktovik, where white-out conditions may be possible at times with blowing snow and reduced visibilities down to less than 1/4 mile at times. Early next week, while there is uncertainty due to potential snow and cloud cover in the area, very cold conditions over the region could drop temperatures into the - 40s or colder at times across much of Eastern Alaska, even outside typical cold spots.

KEY WEATHER MESSAGES

Central and Eastern Interior... - This evening, a system will move into the area and yield snow totals widely reaching 1 to 4 inches through the weekend, with higher totals of over 4 inches possible from the north slopes of the Western AK Range to the White Mountains. Stronger winds at higher elevations may lead to blizzard conditions at times along portions of the Steese and Elliot Highways.

- Winds will begin to increase out of the north through Windy and Isabel Passes tomorrow afternoon and lasting through Saturday morning, with blowing snow and reduced visibilities down to 1/2 mile or less possible at times.

- Cold weather will subside today across the Interior as this system pushes out the cold air mass currently in place. Considerably warmer temperatures are likely for tomorrow, with highs widely rising into the positive single or double digits.

- Early next week, while there is uncertainty due to the chance for light snow or cloud cover, much colder air is going to settle back into the area, especially over the eastern half of the Interior. Some areas, such as the Yukon Flats and Upper Tanana Valley, could see temperatures drop enough to necessitate Cold Weather products.

West Coast and Western Interior... - Warmer temperatures through Friday morning will turn colder into the weekend. Snow, and a wintry mix farther south around Norton Sound, will taper off Friday morning with winds diminishing Friday evening. - Temperatures will return to more seasonal values with initially drier conditions going into the early part of next week.

North Slope and Brooks Range... - Blizzard conditions are expected to begin along the northeast coast by tomorrow morning through Sunday morning, mainly from Prudhoe Bay to Kaktovik. Strong winds right along the coastal areas will have gusts approaching 70 mph. Snow totals will generally be on the lighter side, however, recent snowfall will produce ground blizzards, with whiteout conditions occasionally, and reduced visibilities of less than 1/4 of a mile.

- Southerly winds will begin to increase through Anaktuvuk Pass ahead of the approaching low pressure system by late this evening. Ground blizzards and whiteout conditions are possible through Friday with these winds. They will shift westerly after passage of the front, which will allow them to weaken, but snowfall will likely continue through the weekend.

- Snow is expected to move in across the region going into the weekend as a low moves along the Arctic coast from west to east. 1 to 4 inches of snow are widely possible across the area. Higher totals are possible in the Brooks Range and Arctic Plains, mostly east of the Dalton Highway. Portions of the eastern Brooks Range southeast of Sagwon may receive between 6-8 inches of snow.

- Through the weekend, widespread winds of 25 to 40 mph, with higher gusts, will shift from SW to W and could combine with falling/fresh snow to allow for blowing snow, which could reduce visibilities at times.

FORECAST ANALYSIS AND DISCUSSION

A major shortwave trough with an associated low pressure system will continue to transition across the region today, and the area of low pressure centered over the Chukchi Sea will move over into the Beaufort Sea and allow for the surface pressure gradient to enhance westerly winds across the Arctic Plains. This, combined with the chance of some light snow, and snowfall that is already on the ground, will result in blowing snow for some locations. Along the Northeast Arctic Coast, these winds will greatly increase just offshore, and this will result in blowing snow (whether from precipitation or snowfall already on the ground) which may reduce visibilities down to less than 1/4 mile at times in blowing snow. Snowfall will also begin by later this evening across the eastern Interior, and higher amounts will be possible across the Fairbanks North Star Borough, and especially within the White Mountains, where there back be up to 6 to 8 inches possible through tomorrow. Snowfall and clouds, along with warmer air advection from the west will continue to erode away the colder temperatures at the surface as it breaks the inversion. Supersaturation above the DGZ may prevent snow ratios from being higher than 15:1, although there may still be amounts greater than 4 to 5 inches. There will also be higher amounts east of the Dalton Hwy, within the eastern Brooks Range, where some amounts could reach close to a foot, especially for the higher elevations and along the western-facing slopes. This will continue into Saturday, and then begin to taper off with colder and drier air on the backside which will be moving in behind the exiting trough.

EXTENDED FORECAST DAYS 4-7

After Monday, a strong ridge will continue to build into the central to northern Bering Sea, with extensive troughing across northwestern Canada. On the North Slope, a series of lows is possible on the North Slope moving in from over the Arctic, each of which may produce light snow and bring up the winds (and a possibility of blowing snow), especially on the eastern Arctic coast. A consensus of both ensemble and deterministic models continue to support increased north winds with light snow over Western Alaska late Monday into Tuesday, some extend the snow as far east as the Eastern Interior, while others keep it farther west. This has a significant effect on cloud cover and temperatures, with the drier and clearer solutions being much more conducive to temperatures near or below -40F. The best confidence for such temperatures is on Monday, when temperatures at the 850 mb level across much of Eastern Alaska will range from -25 to -30C. Model guidance suggests the periphery of the ridge aloft could shift into the Interior, allowing for relatively warmer conditions to return to the West Coast, while colder air infiltrates down over the eastern Interior with a return of very cold temperatures by the middle of next week.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Blizzard Warning for AKZ801>803-806-807. Winter Weather Advisory for AKZ834-838>845-847>850. Winter Storm Warning for AKZ813-814-816>824. Blizzard Warning for AKZ815. Blizzard Warning for AKZ804-805. Winter Weather Advisory for AKZ808>810. PK...Brisk Wind Advisory for PKZ802>806-852-853. Brisk Wind Advisory for PKZ808-809-855. Gale Warning for PKZ811. Gale Warning for PKZ812-857-858. Gale Warning for PKZ813. Gale Warning for PKZ814-860. Storm Warning for PKZ815. Small Craft Advisory for PKZ816-851. Heavy Freezing Spray Warning for PKZ816. Small Craft Advisory for PKZ817. Heavy Freezing Spray Warning for PKZ854. Gale Warning for PKZ859. Storm Warning for PKZ861.