textproduct: Fairbanks

SYNOPSIS

Friday, temperatures in most of Alaska will be seasonably warm as we get a brief break between weather systems. Temperatures in the Yukon Flats will continue to be the hottest in the State, in the mid 80s, through Saturday. Friday evening, widespread rain will make landfall in the YK Delta and proceed north across western regions on Saturday. Southerly gap winds through the Alaska Range passes will strengthen Saturday evening. Cloudier, wetter, and cooler conditions will engulf the rest of Alaska by the end of the weekend.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Highs in the 70s and 80s are expected in Interior valleys Friday and Saturday, with a heat advisory in effect for the Yukon Flats where temperatures will reach around 85F. Temperatures will begin a cooling trend from west to east on Sunday.

- Isolated thunderstorms are most likely to form over the White Mountains Friday afternoon, but should also develop over higher terrain surrounding the Yukon Flats and Fortymile Country. Saturday, coverage should shift back towards the Central Interior, over the Dalton Highway Summits and White Mountains north of Fairbanks.

- Southerly gap winds through the Alaska Range will strengthen Saturday afternoon, with potential gusts up to 60 mph through Isabel and Windy Pass.

West Coast and Western Interior... - Highs are expected to reach the lower 70s in Western Interior valleys today. Along the coast, highs will be in the 50s/60s. Temperatures will cool as widespread rain sweeps across the region from south to north on Saturday.

- Widespread wetting rain will arrive in the YK Delta Friday afternoon and travel north through the region through Friday night and Saturday. The current track of the low supports half an inch or more in the the YK Delta and Southern Seward Peninsula on Saturday, around a quarter in the lower to middle Yukon Valley, and less than a quarter in most other regions. - Winds lull Friday before strengthening again Saturday with the arrival of the next system from the Bering. Areas along the coast will see gusts up to 35 to 45 mph. Farther into the Interior, gusts will reach 25 to 35 mph. Winds will weaken slightly on Sunday, but remain gusty through the weekend.

- Fog and low stratus have moved in from the Bering along portions of the West Coast and will linger through the weekend.

North Slope and Brooks Range.. - Max temperatures on the North Slope will cool somewhat on Friday, peaking closer to 70 through the weekend, and into the 60s on Monday. Temperatures along the coast will be cooler, in the 50s and low 60s, and in the 40s around Utqiagvik.

- Scattered thunderstorms are expected in the central and eastern Brooks Range Friday afternoon. The best chances will be in an area from Anaktuvuk Pass to Arctic Village.

- Widespread rain will reach the Western Brooks Range from the south on Saturday and may continue into the Western North Slope on Sunday.

FORECAST ANALYSIS AND DISCUSSION

A weak ridge extends northward from the Alaska Peninsula and over Interior Alaska, providing an opportunity for temperatures to warm back up into the 70s across the majority of the Interior on Friday. The northern Interior, and especially the Yukon Flats, will not have a break from hotter temperatures through Saturday, peaking in the mid 80s each afternoon. Thunderstorms will develop in the Eastern Interior and Eastern Brooks Range Friday afternoon. With the ridge positioned over the Interior, convective development will be limited to isolated storms over the higher terrain. However, the ridge is weaker over the eastern Brooks Range with a weak shortwave riding over the top of it. This will support more significant scattered thunderstorm development in an area from Anaktuvuk Pass to Arctic Village to the AlCan Border. Breezy wind in the Western Interior will diminish at least briefly Friday morning before a trough which is currently over the Bering sends a shortwave into the YK Delta.

Late Friday evening, the trough over the Bering will pull a bit of tropical moisture from the north Pacific toward southwest Alaska. As a result, there will be widespread rain in the western region of Alaska throughout the weekend. Models continue to shift slightly regarding the exact location and amount of rain. Recent runs have brought rain totals up to around half an inch in the YK Delta, Seward Peninsula, and St Lawrence Island, and that's just for Saturday. Total QPF amounts through the end of the weekend are reaching an inch or more on the Southern Seward Pen and along the YK Delta Coast. In addition to the rain, winds along the coast will gust in the 35 to 45 mph range. Farther inland, winds in the western Interior look like they will reach 25 to 30 mph. The center of the low will be positioned over the Seward Peninsula, so while winds will be southerly in the Western Interior, Kotzebue Sound and Norton Sound, they will be northerly through the Bering Strait Coast. The arrival of system will also lead to gusty southerly gap winds through the Alaska Range. Currently wind gusts seem to peak around 45 to 50 mph on Saturday night, as the front crosses the range and the upper level pattern becomes aligned south to north across the Range.

Conditions will begin to cool down in the Central and Eastern Interior on Sunday as the trough gradually bumps the ridge off to the east. Only light showers will make it into the Central and Eastern Interior as most of the heavier precipitation stays to the West. The cloudier and cooler conditions will limit thunderstorm development to the AlCan Border.

FIRE WEATHER

As upper-level ridging persists for the state, thunderstorms continue to be expected for the eastern Interior and the central and eastern Brooks Range today and Saturday. Thunderstorm outflow boundaries on Saturday are forecasted to be especially strong over the Yukon Flats and Eastern Brooks Range. By this afternoon, another low from the Bering begins to approach the state, pushing the ridge eastward and causing high temperatures to rise, especially for the Yukon Flats where a Heat Advisory has been issued through Saturday. As this low approaches, rainfall totals as high as 0.50" in some locations are expected for the West Coast and Western Interior, moderating fire weather concerns for the time being for those areas. Gap winds through the Alaska Range may also increase as the low approaches on Saturday evening into Sunday. Gusts as high as 50 mph are possible, causing potential Red Flag conditions for Delta Junction, though recent heavy rainfall has limited fire weather potential for the Tanana Flats and Upper Tanana. We will continue to monitor this within the coming days.

EXTENDED FORECAST DAYS 4-7

On Monday a low pressure system will be over the Chukchi Sea. A series of strong open wave troughs will lift through southwest Alaska and track over the Interior through Wednesday. Clouds and widespread showers will continue over the West Coast, Western Interior and the Alaska Range during this time. With a strong southwest flow some of that moisture should make it into the central Interior for scattered rain and isolated thunderstorms despite some blocking from the Alaska Range. The Yukon Flats and eastern Brooks Range have the lowest chance for significant rain through Wednesday. Gap winds will continue to be monitored through the Alaska Range passes. A cooling trend is likely to occur with the Interior seeing highs in the low 70s with mid 50s. Highs should be mid 50s to lower 60s on the West Coast and North Slope.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Heat Advisory for AKZ833. PK...Small Craft Advisory for PKZ811. Small Craft Advisory for PKZ857. Small Craft Advisory for PKZ858.