textproduct: Fairbanks

SYNOPSIS

Snow showers along the North Slope continue through Thursday with potential for significantly reduced visibility from blowing snow along the Eastern Arctic Coast until winds diminish Thursday morning. There are chances for rain and snow showers in the Interior through the rest of the week. A cool and dry airmass settles over Alaska resulting in below average temperatures for most locations going into the weekend.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Expect scattered rain/snow in the Southern and Eastern Interior. Rain will be favored during the day with snow favored overnight and at higher elevations. Minimal snowfall accumulations are expected.

- Daytime high temperatures will be cooler through Saturday, likely only reaching the mid/upper 40s Wednesday and Thursday. Similarly, low temperatures will cool into the low 30s, allowing for some patchy areas of frost to develop overnight.

- Winds across the Interior will be westerly with occasional gusts up to 20 mph through Wednesday night. On Thursday, winds become light and northeasterly before restrengthening on Friday.

West Coast and Western Interior...

- A cool, dry air mass will settle over the western half of the state, resulting in cooler temperatures through the weekend. High temperatures will struggle to reach the 40s in the Western Interior Wednesday and Thursday and will be colder along the coast. Lows will range from the upper teens across the Seward Pen and Kotzebue Sound to the low 20s in the Western Interior.

- North/northwest winds strengthen Wednesday afternoon along the Northwest Arctic Coast and Kotzebue Sound. On Thursday, strong northerly winds begin to develop through the Bering Strait, dropping slightly overnight Thursday before restrengthening again Friday with gusts up to 25 mph through the Strait.

- Dry air has cleared skies across most of Western Alaska. However, low stratus clouds are spread along parts of the coast and areas of low clouds will likely persist through Thursday.

North Slope and Brooks Range...

- Snow showers continue in the Central/Eastern Brooks Range and across the Eastern Arctic Coast through Thursday. Additional snow accumulations of 2 to 3 inches are possible on the eastern half of the North Slope by the end of the day Thursday.

- Total snow accumulations between 4 to 8 inches are possible through Atigun Pass as the frontal boundary stalls over the Central Brooks Range Tuesday through Wednesday.

- Westerly winds gusting up to 40 mph will significantly reduce visibility east of Point Thomson with similar conditions to a lesser extent farther west along the coast. Winds will diminish Wednesday night.

- North to northeast winds, at times gusty, will develop Thursday evening and strengthen gradually through Saturday morning. There may be enhanced northerly gap winds trough Central Brooks Range Passes on Friday with gusts up to 30 mph.

- Conditions begin to clear along the North Slope as high pressure descends from the Arctic on Thursday.

FORECAST ANALYSIS AND DISCUSSION

The big-picture upper-level pattern over Alaska this morning is a 548 decameter ridge over the Bering Sea and general troughing over the mainland. Within the large-scale trough over Alaska are two shortwave troughs, one over Cook Inlet and another over Mackenzie Bay, and a 521 dam low over the western Arctic Coast. Both of the shortwaves have associated surface lows, which will result in areas of precipitation and gusty winds in the Southern Interior and Western Arctic Coast. The low over Mackenzie Bay is deeper and carrying more moisture, resulting in widespread snow along the eastern half of the Brooks Range and North Slope, as well as strong northerly winds through the Central and Eastern Brooks Range and strong westerly winds along the Eastern Arctic Coast. The low in South Central Alaska is less impressive, but it is still supporting showers in the southern Interior and enhanced gap winds through Isabel Pass. The impact of both these features will diminish through the day Tuesday as they move to the northeast.

Thursday morning, the upper-level low descends into the Western Interior, pulling cold, dry air over most of Western Alaska. There are slight chances for precipitation in the Western Interior along with the passage of the low, but accumulations are light. At the surface, high pressure extends down into the Bering from the Chukchi Sea, northerly winds begin to strengthen through the Strait and into the Western Interior. That high builds in over the entire North Slope resulting in northeasterly winds across most of the Interior by Thursday afternoon. The exception will be the last of some southerly winds in the southeast Interior. That southerly flow will supply the eastern Interior with enough moisture for some light showers on Thursday as well.

Friday the upper-level pattern remains mostly the same with a 523 dam low now over the southwest Interior, generally colder temperatures through Northern Alaska and showers in the Eastern Interior which could also expand to include the Central and Eastern Brooks Range. However, a new low is approaching the Gulf of Alaska from the South and the leading edge of that system looks to begin impacting our area Friday afternoon. the initial impacts being rain and a bump in temperatures in the Southeastern Interior.

EXTENDED FORECAST DAYS 4-7

At the start of the extended forecast period, Saturday morning, dry cold northerly air should still be keeping most of the North Slope and West Coast regions free of precipitation. However, the low in the Gulf will produce more widespread precipitation in the Central and Eastern Interior as it approaches the coast. Models predict snow in the Eastern Brooks Range and along the Eastern Arctic Coast overnight Saturday and rain in the Interior. Lighter showers continue in the Interior on Sunday, with the ECMWF continuing to show decent lightning chances in the Southeast Interior.

On Sunday and Monday ensemble model guidance keeps us in a pattern of low pressure systems moving into Alaska as high pressure tries to establish itself. This will likely mean more active weather and cool to average temperatures for the start of next week.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Flood Watch for AKZ835.

PK...Heavy Freezing Spray Warning for PKZ812. Brisk Wind Advisory for PKZ814-860. Brisk Wind Advisory for PKZ815-861. Heavy Freezing Spray Warning for PKZ858.