textproduct: Fairbanks

SYNOPSIS

Hot conditons will persist in the Northern Interior, and particularly in the Yukon Flats where temperatures will have potential to reach the mid 80s through Saturday. Conditions will be cooler and wetter in the Tanana and Kuskokwim Valleys as a band of rain continues west across the Southern Interior Thursday morning. Thunderstorm coverage shifts eastward from the Central Interior on Thursday toward the Eastern Interior for the weekend. Widespread rain will arrive for the western regions on Saturday.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Highs in the 70s and 80s are expected in the northern Interior, with a heat advisory in effect for the Yukon Flats where temperatures will reach around 85F. Temperatures will be cool in the southern Interior Thursday before warming into the 70s Friday.

- Rain is expected in the southern Interior Thursday morning. Around a quarter of an inch is expected along the north side of The Alaska Range before rain disperses this afternoon.

- Isolated thunderstorms will be possible from the White Mountains to Tanana northward and northern Fortymile Country and along the AlCan Border on Thursday and Friday.

- Southerly gap winds through the Alaska Range will strengthen Saturday afternoon. Wind gusts up to 40 mph through Isabel and Windy Pass are possible by Saturday evening.

West Coast and Western Interior... - Rainfall along the northern slopes of the Western AK Range and in the Upper Kuskokwim Valley could produce additional totals of around a quarter of an inch through Thursday Morning.

- Temperatures cool slightly with highs in the lower 70s in Interior valleys today. Along the coast, highs will be in the 50s/60s.

- Stronger southwesterly/westerly winds with gusts up to 20 mph will be possible throughout the western Interior Valleys through Thursday night. Winds lull Friday before strengthening again Saturday.

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

North Slope and Brooks Range.. - Warm temperatures persist through Thursday. Highs warm into the 50s near Utqiagvik to the low 80s in the Arctic Plains. A heat advisory is in effect for the Arctic Plains for Thursday. Max temperatures on the North Slope will be closer to 70 on Friday and Saturday, and into the 60s on Sunday.

- Isolated thunderstorms will be possible in the Central Brooks Range and Arctic Plains on Thursday. On Friday, the eastern Brooks Range will see scattered thunderstorms.

- 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

The upper-level pattern consists of a weak ridge over the north and west portions of Alaska, and a 547 decameter low moving quickly from west to east across the Gulf of Alaska. There is troughing through the Western Bering, which will play an important role in delivering widespread rain to western Alaska on Saturday. Presently, there is rain across much of the Southern Interior which will dissipate through Thursday morning as the low in the Gulf moves to the southeast. Up to a quarter inch of additional precipitation is possible in the Kuskokwim and Tanana Valleys as upslope flow against the Alaska Range wrings out the remaining precipitation. Then, Thursday evening, another round of rain looks to wet the upper Tanana Valley again, before the low finally exits the Gulf into British Columbia and warmer, drier weather arrives for the Interior. Thunderstorms will develop in the afternoon under the weak ridge. On Thursday, the best corridor looks to be from around Tanana to the Central Brooks Range, and north into the Central Arctic Plain. On Friday, coverage shifts east but storms remain isolated in the Interior, developing over the higher terrain in the eastern Interior. The exception will be in the Eastern Brooks Range, where more scattered thunderstorms will develop. By Saturday, thunderstorms are pushed to the eastern Interior along with the weak upper-level high pressure.

After the rain subsides in the Southern Interior Thursday, temperatures will be cool, only peaking in the 60s. However, with the ridge sliding east over the Interior on Friday, temperatures will warm back up into the mid 70s. The northern Interior, and especially the Yukon Flats, will not have a break from hotter through Saturday, peaking in the mid 80s each afternoon. Apart from the hotter temperatures in the Yukon Flats and thunderstorms, the weather becomes relatively benign on Friday.

Early Saturday morning, the trough over the Bering will make landfall in the YK Delta, managing to pull a bit of tropical moisture north along with it. As a result, there will be widespread rain across the western regions of Alaska. Totals are still somewhat uncertain but recent runs have trended upward, leading to widespread areas of 0.25 inches with pockets up to half an inch. Rain totals will depend on exactly how much moisture the part of the trough in the North Pacific is able to steal away from a ridge in the Pacific. Along with the precipitation out west, the arrival of system will also lead to gusty southerly gap winds through the Alaska Range. Currently wind gusts are peaking around 40 mph, but it could be that as the day gets closer, that it will increase towards 45 or 50 mph. I will be keeping an eye on that.

EXTENDED FORECAST DAYS 4-7

Sunday through Wednesday. Ensemble models remain in reasonable agreement for Sunday, with around a 545 dm upper level low centered over St. Lawrence Island, a 555 dm low in the Gulf of Alaska, and a 560 dm ridge of high pressure centered over the Alcan Border. This setup will remain conducive for efficient southwest moisture transport into Northern Alaska, supporting scattered to widespread rain chances across the western two thirds of our CWA, while the ridge of high pressure closer to the Alcan Border and the Yukon Territory work to limit precipitation chances to more isolated. Given more breaks in the clouds farther east, isolated to scattered thunderstorm chances and warmer conditions will be found in the Eastern Interior and Eastern Brooks Range, while cooler and wetter conditions are expected farther west with cloudier and rainier weather in place. As that broad trough over the Bering Sea shifts east for early next week, look for temperatures to stabilize or see a cooling trend across our region as daily precipitation chances persist, keeping around our unsettled weather pattern around through at least midweek next week.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Heat Advisory for AKZ833. Heat Advisory for AKZ806-808. PK...Small Craft Advisory for PKZ804-805. Small Craft Advisory for PKZ807. Small Craft Advisory for PKZ856.