textproduct: Fairbanks

SYNOPSIS

Warm conditions will be possible across the area through midweek, with widespread highs in the 70s and 80s in inland areas, with 50s and 60s in the cooler coastal areas. Showers and thunderstorms will be possible across much of the area each day; the best chances will be in Western Alaska and in the higher terrain of the eastern Interior, with more isolated thunderstorms possible in much of the remainder of the area. By later this week, somewhat cooler temperatures will be possible, with decreasing thunderstorm chances but potentially increasing rain chances.

KEY WEATHER MESSAGES

Central and Eastern Interior... - A warming and drying trend will continues across the Interior through Tuesday with daytime temperatures rising into the 70s and lower 80s. A heat advisory is in effect for the Yukon Flats for highs near 85F Tuesday and Wednesday. Temperatures cool late Wednesday into Thursday.

- Isolated thunderstorms will be possible today across much of the Central and Eastern Interior with the exception being the Yukon Flats. Thunderstorms will also be possible in the Alaska Range, mostly on be the northern slopes.

- Tuesday night and into Wednesday, southerly flow through Isabel Pass could briefly support winds gusting up to 40 mph.

West Coast and Western Interior... - Temperatures will continue to rise across the region with daytime highs in the 70s and low 80s in the Western Interior valleys. Along the coast, highs will be in the 50s/60s. Temperatures will cool across the region on Wednesday.

- Scattered to numerous thunderstorms are expected today across the southern half of the Western Interior. The Kuskokwim mountains will see the brunt of the storms, but as those storms move west to southwest, they could potentially move into the valleys. The thunderstorm threat will shift northward tomorrow across the whole Western Interior, with another chance for scattered to numerous storms.

North Slope and Brooks Range.. - Warm temperatures expected. Daytime temperatures warm into the 50s near Utqiagvik to near 80F on the Arctic Plains. A heat advisory is in effect for the Arctic Plains from Monday through Wednesday.

- Isolated thunderstorms will be possible in the Brooks Range and Central Arctic Plains today. These chances will continue on Tuesday and Wednesday, when scattered thunderstorms will be possible from there to the Arctic Coast.

FORECAST ANALYSIS AND DISCUSSION

A 569 dm ridge aloft at the 500 mb level persists across the northern and northeastern reaches of Alaska to start the period. At the 850 mb level, temperatures with the ridge today will range from 10 to 15C over the Central and Eastern Interior and Brooks Range, with upper single digits in the Western Interior. This will coincide with surface temperatures rising into the upper 70s or low 80s across most of the Interior and the inland portions of the North Slope. Closed lows are in place in the eastern Bering Sea and the northern Gulf of Alaska. Along the interface of these lows and the ridge in northern Alaska in the Central Interior, a shortwave trough will move from east to west into the Western Interior, then from south to north. As this occurs, periods of showers and thunderstorms will be possible across much of the Interior but especially in the southwestern Interior, where they may be numerous. Hundreds of J/kg of surface-based CAPE and LIs of 1 to 3 C will be available to support these storms.

Moving into Tuesday, the ridge will begin to shift eastward, as will the Bering Sea low. Surface temperatures will nonetheless remain quite warm across the Interior and southern North Slope, with another day of widespread 70s and 80s expected, with cooler conditions over coastal areas. A more substantive shortwave moving in from southwestern Alaska will traverse the Western Interior and Western Brooks Range, with showers and scattered to numerous thunderstorms possible in these areas, with isolated thunderstorms farther east. CAPE and LIs in the most favorable areas will be similar to those Monday.

Wednesday, the ridge will retreat even farther east into northwest Canada. Abundant moisture will flow into southwestern Alaska on the north side of the Bering Sea low, which by this point will be shifting eastward toward the Gulf, while the Gulf low moves into southeast Alaska. Yet another round of shortwave energy coupled with this moisture and a third day of good instability will support isolated to scattered thunderstorms and numerous showers in the Northern Interior and North Slope, especially farther west. Some of the thunderstorms could potentially affect coastal areas of the Arctic.

By the late-week time frame, there is higher uncertainty on what happens with the ridge, but it could be shifted somewhat northeastward with lower pressure aloft possible in the Interior. This will coincide with potential scattered to numerous showers and cooler temperatures in the Interior and on the North Slope.

FIRE WEATHER

Tuesday a broad area of high pressure will continue to slowly transit east, while a closed low undercuts the state, moving east across the Gulf of Alaska. A consequence of this synoptic dance will be the general shift of southerly flow over the Central and Western Interior, serving as the catalyst for more vigorous thunderstorm development, even as far north as the Arctic Plains. While thunderstorms hammer the west and northern portion of the state, temperatures will continue to increase, reaching 75F to 85F over many locales. Min RH will also continue to reach critical thresholds of 20 to 30 percent, with the driest regions focused across the northwest and Yukon Flats. With that said, the Tanana Flats into the lower Tanana continues to be quite dry, a testament to the uptick in initial attacks over the area.

Wednesday, an inverted trough moves across the central portions of Alaska, bringing another beefy thunderstorm day across the state. Thunderstorms will likely shift further into the northwest, perhaps as far as Point Hope/Wainwright. This pattern will bring increased chances for wetting rains, and some relief in temperatures and min RH, for the western Interior.

All eyes continue to track how the broad area of high pressure moves by the end of the week, with general model consensus that the northeast part of the state, from Yukon Flats to Mackenzie Bay, will remain under the influence of this high.

EXTENDED FORECAST DAYS 4-7

The extended period begins on Friday with a trough developed over Eastern Siberia and a high pressure system over the Northeast of Alaska. As the trough extends southeast towards the Gulf of Alaska Friday through Saturday, the high pressure system weakens slightly, and is forced eastward out of Alaska. This pattern suggests that showers will become more likely throughout the majority of Northern Alaska. Model guidance supports the first round of precipitation staying focused around the West Coast/Western Interior of Alaska on Saturday, and the second round reaching into the Central Interior as well on Sunday.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Fire Weather Watch for AKZ916-918-919-928. Red Flag Warning for AKZ918-919-923-928-929. Heat Advisory for AKZ833. Heat Advisory for AKZ806-808. PK...None.