textproduct: Fairbanks

SYNOPSIS

A Bering Sea low pressure system will move into the Gulf of Alaska this weekend. This system will rotate a series of shortwaves up into the Alaskan Range and Kuskokwim valley with cloudy, cooler and showery conditions through the weekend. Behind this system a high pressure ridge builds over the North Slope with a stationary front setting up just south of the Brooks Range. A warming and drying trend will occur into next week for much of the Interior and Northern Alaska. Isolated thunderstorms are Friday and Saturday over the higher terrain and along the stationary frontal boundary.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Clouds, showers and cooler conditions will increase over the Alaskan Range Friday into the weekend. Elsewhere in the Interior a warming and drying trend will occur with daytime temperatures in the 70s.

- Isolated showers and thunderstorms will develop over the mountains Friday and Saturday.

West Coast and Western Interior... - Cloudy, rainy and cooler conditions will occur along the southwest coast into the Kuskokwim Valley on Friday. Gusty northerly winds will continue Friday.

- Temperatures remain in the 50s and 60s today across most of the region, but there will be a gradual warmup this weekend.

- Isolated showers and thunderstorms will occur over the higher terrain of the Western Interior Friday and Saturday.

North Slope and Brooks Range.. - High pressure develops over Northern Alaska with a gradual warming and drying trend Friday through the weekend. Foggy conditions will develop along the Arctic Coast.

- Gusty northerly winds will continue into Saturday across the Brooks Range with 20 to 30 mph winds through the passes.

- Isolated thunderstorms are possible over the Brooks Range Friday and Saturday.

FORECAST ANALYSIS AND DISCUSSION

Shortwave energy and associated moisture from the Yukon will linger into Friday across the upper Tanana Valley, Fortymile Country and the Yukon Flats. This moisture will shift east from Alaska this weekend with some warming and drying developing. Isolated afternoon and evening thunderstorms will still pop over the mountains of the Eastern Interior this weekend.

The next upstream system in the Bearing Sea will impact the Southwest Coast and Kuskokwim Valley with cloudy, cooler and showery conditions through Saturday. This system moves into the Gulf of Alaska this weekend spreading moisture up into the Alaskan Range and back into the upper Tanana Valley by Monday. Projections are showing most of the Fortymile and the Yukon Flats will miss this moisture return on Monday continuing a drying trend. Similarly there will be some temporary drying along the West Coast and Kuskokwim Valley Sunday and Monday before the next upstream system moves into the Bering Sea.

Up north a high pressure ridge extending from Siberia develops over the Arctic Coast and North Slope, strengthening down over the Northern Interior early next week. The airmass will be stable under this ridge diminishing shower and lightning activity. As this ridge builds, a northerly pressure gradient with gusty northerly winds develops over the Brooks Range Friday and Saturday. This downslope flow will enhance the warming and drying in the northern Interior.

FIRE WEATHER

Warm and dry continues for most of the state, with thunderstorms expanding westward Friday. As the thunderstorm footprint pushes west, a dry cold airmass will move into the North Slope, bringing breezy northerly winds into the Brooks Range and Seward Peninsula. Northerly to northeasterly winds will move into the northern Interior, perhaps bringing very slightly cooler temperatures; however, RH will still reach into critical thresholds.

The hot and dry footprint increases into the weekend for our entire area, with temperatures heading back into the upper 70s/mid 80s and min RH back down to near 20 to 35 percent by Mon/Tue. The focus for 80F to 85F temps and min RH near 20 percent will be Bettles into the Yukon Flats. This period for the weekend into the start of next week will bring ample opportunity for the region to dry out, with the ridge breakdown sometime near Wednesday bringing thunderstorms back to the interior. Main concern remains in the central and northern interior, with troughing along the west coast moderating fire weather concerns from McGrath southwest into the lower Yukon.

We are not out of the fire season yet.

EXTENDED FORECAST DAYS 4-7

Monday through Wednesday

High pressures will be the dominant weather feature over Northern Alaska early next week. 850mb temperatures peak in the 10-12C range under this dome of stable air next Tuesday and Wednesday. Above normal temperatures with dry conditions are expected. The next Bearing Sea low pressure system is projected to move eastward across the Northern Gulf of Alaska by Wednesday. Shortwave energy and moisture will circulate up into the Southwest Coast and the Alaska Range as this system tracks through. Models appear to be too strong and fast with the return easterly flow in the deformation zone over the Central and Eastern Interior, but that is our consensus forecast attm for the middle of next week. That will result in increasing thunderstorm activity as the high pressure ridge presumably breaks down. We will continue to monitor that situation for the potential fire weather implications.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. PK...Small Craft Advisory for PKZ806-807-816-851-854-856. Small Craft Advisory for PKZ810. Small Craft Advisory for PKZ811. Small Craft Advisory for PKZ817. Small Craft Advisory for PKZ857.