textproduct: Fairbanks

SYNOPSIS

A frontal system pushing across Northern Alaska is bringing areas of rain and snow to much of the Interior. Gusty south winds in the Alaska Range will diminish through this evening. In the Central and Eastern Brooks Range and on the North Slope, snow could be heavy in some areas. On the eastern Arctic Coast, blowing snow will is expected from this evening into Thursday with gusty westerly winds. Colder conditions are expected across the Interior/West Coast beginning Wednesday and Thursday, with isolated thunderstorms in the Eastern Interior Thursday afternoon.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Southerly winds through the Alaska Range passes are gusting at 30 to 45 mph but will decline through the night tonight.

- A cold front brings colder, occasionally gusty winds and chances for precipitation into the Interior Tuesday afternoon. Expect widespread rain/snow in the Central and Northeastern 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 Thursday, likely only reaching the mid/upper 40s Wednesday. Similarly, low temperatures will cool into the low 30s, allowing for some patchy areas of frost to develop overnight.

West Coast and Western Interior...

- Frontal rain/snow in the Western Interior including near McGrath is expected to end outside the mountains by late this evening into tonight.

- Breezy north/northwest winds strengthen Tuesday night as the front advances inland. Interior winds subside Wednesday evening but remain strong along the Northwest Arctic Coast and into Kotzebue Sound. Thursday, the strongest winds move to the southern Bering Strait.

- Temperatures will remain cooler than average across the western half of the state. High temperatures along the coast will be in the low 40s farther inland. Lows will range from the upper teens across the Seward Pen and Kotzebue Sound to the low 20s across the Western Interior.

North Slope and Brooks Range...

- Snow showers continue in the Central/Eastern Brooks Range and across the Eastern Arctic Coast. Widespread snow showers are expected to reach Utqiagvik by late Tuesday night. Snow accumulations of 4 to 7 inches will be possible through Thursday between Utqiagvik and Nuiqsut.

- 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.

- North to northeast winds, at times gusty, will allow for localized areas of blowing snow to develop through Wednesday night where there is fresh and/or falling snow.

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

FORECAST ANALYSIS AND DISCUSSION

Rain and snow is occurring across parts of the Interior along a stationary front extending from the Western Brooks Range northeastward to the Central/Eastern Brooks Range. With a cold air mass across Western Alaska, there is a gradient of precipitation type across the front, with snow on the back side in the colder air and rain ahead of it. This will shift eastward through this afternoon, with showers likely across the Eastern Interior by late Wednesday morning. Snow will also be possible with any showers overnight tonight as temperatures cool down. Snow will also be favored in the higher elevations (especially above 2000 feet), including the White Mountains, Dalton Highway Summits, and the Alaska and Brooks Ranges. Any snow that manages to accumulate in Interior valleys will likely be short-lived due to abundant surface heating during the daytime periods and residual ground heat.

In the Central and Eastern Brooks Range, final snow totals through Wednesday morning could exceed 6 to 8 inches with upslope flow. In the Arctic Plains and on the Arctic Coast, most areas will see the potential for at least a couple inches of snow through Thursday. Along the Arctic coast between Utqiagvik and Nuiqsut, around 4 to 7 inches of snow will be possible, with higher totals possible offshore over the sea ice. On the eastern Arctic Coast, the winds are currently light but will turn to the west tonight as the front moves north. Given the likelihood for a couple inches of light snow during this same time frame, blowing snow will be possible with these winds. On Wednesday, as a shortwave trough transits across the Eastern Interior from the southwest, isolated thunderstorms will be possible in the area, especially in the Fortymile Country. Any storms will likely be limited to mostly the higher terrain near the eastern border of Alaska.

FIRE WEATHER

High temperatures in the Middle and Upper Yukon Valleys, the Fortymile Country, and the Yukon Flats will fall from the 50s today in most areas into the 40s Wednesday behind a front. Showers will occur along the front as it shifts east but will likely drop under a tenth of an inch of additional liquid-equivalent precipitationin most Eastern Interior valleys. Highs will rise back into the 50s by Friday with potential further warming early next week. In the Western Interior, cooler conditions in the 40s or upper 30s will prevail through the period with a cold airmass focused over the area, although the dry air in place will permit min RH values in the 40s and 50s. Minimum relative humidity values in the 30s and 40s are likely across the Upper Tanana Valley and Fortymile Country today and will expand to the Yukon Flats and Middle Tanana Valley from Wednesday through Friday. Parts of the Delta Junction to Tok areas could see RHs fall into the 20s. Warmer and drier conditions will be possible early next week with the chance for southerly downsloping across the Alaska Range.

HYDROLOGY

***NEW*** A Flood Warning has been issued at Eagle at 4:30PM AKDT Tuesday May 5th. According to reports from Eagle, the ice has stopped moving and water has begun to gradually rise. River water has been observed on the road between the town and village. If the ice jam continues to impound water, this may result in rapid rises upstream.

Otherwise, as of 10 am the local breakup front had not yet reached Calico Bluffs. Aerial observations on Monday found all Yukon tributaries from the Canadian border to Coal Creek open and creating small areas of open water where they entered the Yukon. The ice in the same region was showing signs of weakening. A flood watch was issued for the Upper Yukon region (Canadian border to Coal Creek). Ice jams may form as the breakup front progresses downriver and cause localized flooding. Downstream of Coal Creek the ice appeared to be stronger (more white/blue ice) and more remnant snow remained in the low lands. River Watch flights will begin on Wednesday (weather permitting) and updates on breakup progression will be provided as information becomes available.

If you live near or along the Yukon River monitor ice movement and water levels; stay alert and be prepared to take action. Stay tuned to further developments by listening to your local radio, television, or NOAA Weather Radio for further information.

For online information, see http://www.weather.gov/aprfc

EXTENDED FORECAST DAYS 4-7

Friday through Monday. Cold air will still be present in Western Alaska with an amplified trough in place over the area. Substantial moisture with a shortwave trough/front from the North Pacific will push into the Eastern Interior Saturday; this will allow for scattered to numerous showers, mostly over the higher terrain, across much of Northern Alaska moving into next week. Southerly flow on the east side of the trough could lead to much warmer conditions by Sunday. Troughing could begin to shift westward by late this weekend into early next week, although there is high uncertainty on exactly how this could play out due to model uncertainty. Regardless, south flow is likely to persist, with temperatures potentially nearing 60 in Interior valleys next week and continuing showers across much of Northern Alaska, especially in the higher terrain.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Flood Watch for AKZ835. Winter Weather Advisory for AKZ805. PK...Brisk Wind Advisory for PKZ808-809. Heavy Freezing Spray Warning for PKZ812-858. Brisk Wind Advisory for PKZ814. Gale Warning for PKZ815-861. Brisk Wind Advisory for PKZ859. Brisk Wind Advisory for PKZ860.