textproduct: Fairbanks

SYNOPSIS

Warm summertime conditions prevail through this evening across Eastern Alaska while cool and wet weather continues out west. High temperatures in the 70s and 80s are expected across the Central/Eastern Interior and Arctic Plains this afternoon where Heat Advisories remain in effect until 10pm late this evening. Southerly gap winds upwards of around 55 mph remain possible through this evening through Isabel Pass, but will gradually diminish through the evening. Inversely, a lingering low pressure system in Bristol Bay continues to support scattered rain showers across Western Alaska, keeping temperatures fairly cool through Tuesday. A new pattern starts to dominate Tuesday into Wednesday as the upper level ridge over Eastern Alaska breaks down and allows for broad-scale troughing and southwesterly flow to move in over the state. The new pattern will support widespread showers across Northern Alaska and a return to cool and wet weather across the Interior by midweek. Looking ahead, a Bering Sea low is still expected to move over Western Alaska Wednesday into Thursday causing some minimal coastal impacts as well as some high surf being possible. There remains some uncertainty regarding the exact track of the low, but we will continue to monitor its development over the next few days.

KEY WEATHER MESSAGES

Central and Eastern Interior... - High temperatures peak this afternoon in the low to mid 80s, with the hottest temperatures in the Yukon Flats and Fortymile Country. Heat Advisories are in effect for highs near 85F to 90F possible. Temperatures cool back into the 60s/70s by Tuesday onwards.

- Isolated to scattered thunderstorms return this afternoon through Tuesday over the Northern and Eastern Interior. The most active spots will be over the Fortymile Country today and over the Yukon Flats tomorrow.

- Southerly gap winds with gusts to around 55 mph through Isabel Pass linger through this evening, diminishing through tonight. Another round of enhanced southerly gap winds are expected through the Alaska Range Passes, particularly Isabel Pass Tuesday night into Wednesday morning.

West Coast and Western Interior... - Widespread continuous showers are expected through early this week with the highest rainfall totals in the YK Delta, southern Seward Peninsula, & Kobuk Valleys. Rainfall totals between 0.25" to 0.50" with locally higher amounts near 0.75" are possible through Tuesday. - Isolated thunderstorms remain possible over the Seward Peninsula and Nulato Hills this afternoon with isolated thunderstorms possible again Tuesday afternoon with chances tapering off by Wednesday.

- A Bering Sea low approaches the state on Wednesday and is expected to support widespread moderate to heavy rain showers and some gusty winds across the West Coast. The primary concerns right now are high surf and minor coastal flooding, but impacts look to remain minimal. (See the coastal section for additional information)

North Slope and Brooks Range... - Scattered showers continue over the Brooks Range and Arctic Plains today, with isolated to scattered thunderstorms possible over the Central/Eastern Brooks Range this afternoon through Tuesday.

- Temperatures peak this afternoon in the 70s to near 80F over the Arctic Plains where a Heat Advisory is in effect through 10 PM tonight. By Tuesday, temperatures start to gradually cool back into the 50s/60s through the week.

- Areas of low stratus and patchy fog may continue to develop during the evening/overnight along the Arctic Coast through midweek.

- Colder low temperatures as low as the 20s & 30s will be in store along the northern slopes of the Brooks Range as we move into the weekend.

FORECAST ANALYSIS AND DISCUSSION

No significant changes to the ongoing pattern as upper level troughing prevails over Western Alaska and an upper level ridge sits over Eastern Alaska. Between these two features, southerly Chinook flow persists keeping the Central/Eastern Interior north towards the Arctic Plains warm and dry. High temperatures at or above 85F to 90F are expected to continue in the Yukon Flats and Fortymile Country this afternoon while the Arctic Plains will continue to see temperatures nearing 80F this afternoon. Heat Advisories remain in effect for these regions through 10 PM tonight. Elsewhere, expect high temperatures in the low to mid 80s across the Central/Eastern Interior with cooler temperatures out in the western zones in the 50s/60s. In addition to warm temperatures, isolated to scattered thunderstorms are possible this afternoon through the evening for the Seward Peninsula, Eastern Interior, and Central/Eastern Brooks Range. The most active areas are expected to be over the Fortymile Country and southern slopes of the Eastern Brooks Range. While not as strong as yesterday, southerly gap winds through Isabel Pass may continue to gust upwards of 55 mph through this evening before progressively diminishing overnight as the pressure gradient relaxes & the temperature cools. A Wind Advisory remains in effect through late this evening for Isabel Pass. As for Western Alaska, cool and wet weather continues as a lingering low pressure system around Bristol Bay continues to push multiple shortwaves and fronts through the area.

A noticeable change in the pattern begins late tonight into Tuesday as the upper level ridge over Eastern Alaska breaks down and gives way to broad-scale troughing. Southwesterly flow then sets up over the state and allows for a front to push widespread showers across Northern Alaska Tuesday through Wednesday. This front will have a northwest to southeast orientation and move northward across the state from the YK Delta. Expect rainfall totals between 0.10" to 0.25" across the Interior with locally higher amounts around 0.50" possible. As this front lifts north, it will also help to initiate additional isolated to scattered thunderstorms across the Eastern/Northern Interior, the Brooks Range, & the Seward Peninsula, once again, Tuesday afternoon. Thunderstorm activity diminishes on Wednesday but looks to potentially pick back up again going into the weekend.

One particular feature of note we will be monitoring over the next few days will be a Bering Sea low approaching the West Coast on Wednesday. Although not very strong (around 550 dm or 999 mb at the SFC), this system may present minor coastal impacts in addition to some potentially high surf, moderate-to-heavy heavy rains, & gusty winds. However, the extent of impacts from this system will be highly dependent on what track the low takes, which remains a bit uncertain, but now, guidance looks to be shifting the track a bit more south, more toward the YK Delta region. More information on this system is in the "Extended Forecast" and "Coastal Hazard Potential" sections.

FIRE WEATHER

Broad upper-level troughing over the western side of the state and ridging over the east still persists. This is creating southerly flow through Delta Junction and the Alaska Range, specifically Isabel Pass, through this evening. This ridging over the eastern portion of the state is continuing to cause warming and drying conditions, especially for the Yukon Flats, Fortymile Country, and Arctic Plains where heat advisories remain in effect until 10pm AKDT this evening. Temperatures as high as 85F to 90F this afternoon will be possible in these areas with min RHs as low as 25%. By Tuesday, temperatures will begin to fall and min RHs will rise. A few isolated to scattered thunderstorms will be possible this afternoon and Tuesday for these areas, as well.

A coastal storm is expected to move into Western Alaska Wednesday into Thursday with widespread precipitation and gusty winds moving across all of Northern Alaska mid to late week. Cooler temperatures will accompany this system as widespread highs in the 50s/60s return, with locally colder low temperatures farther north, particularly along the north slope of the Brooks Range as we move into the weekend.

HYDROLOGY

No concerns at this time.

EXTENDED FORECAST DAYS 4-7

For Friday through Monday.

By Thursday morning, the 540 decameter low over the Bering Sea will begin to be pushed to the northeast by ridging building to the west. Between Thursday morning and Friday morning, model guidance is hinting towards this low moving up and over the North-Pacific high in the gulf. During this timeframe, another push of moisture over Northern Alaska will support additional scattered showers with the highest chances expected for the Central Interior and Middle Yukon. Some isolated thunderstorms are likely over the Eastern Interior Thursday afternoon into the evening. A front moving in from the north is likely to bring light snow accumulations to the Central Arctic Plains and Eastern North Slope/Brooks Range Thursday night through Friday night. Chances of freezing rain or a wintry mix are possible over coastal areas between Utqiagvik and Kaktovik. Friday night into Friday morning, a ridge is expected to push out any residual moisture to the east. High temperatures on the North Slope are expected to drop from Thursday to Friday into the upper 40s/lower 50s with overnight lows reaching 10 to 20 degrees just north of the Brooks Range. By Saturday, highs are expected to recover into the upper 50s.

Models are showing the indication for an Arctic trough to begin digging down from northern latitudes by Saturday night into Sunday morning. This trough is expected to bring a band of additional rain and snow over the North Slope through Sunday, eventually breaking up as it moves over the Brooks Range and brings scattered showers to the Interior by Sunday night.

Coastal Hazard Potential

We have issued a Special Weather Statement for potential coastal impacts later this week from a Bering Sea storm. The main things we are monitoring are the track and strength of the storm but there is uncertainty with both of these. The good news is, the storm doesnt look to intensify too much and impacts should be minor. The West Coast from the Yukon Delta to Kivalina should continue to monitor the latest forecasts, but the latest model guidance suggests that the low could take a more southerly track more toward the YK Delta region. Stay tuned to weather.gov/fairbanks to stay up-to- date & aware of potential impacts from this storm.

Current coastal flood guidance is hinting at high surf and potentially minor flooding. Fortunately, significant impacts are not expected. We will continue to update as necessary.

AFG WATCHES/WARNINGS/ADVISORIES

AK...Wind Advisory for AKZ849. Heat Advisory for AKZ806-808-833-835. PK...Small Craft Advisory for PKZ801-850. Small Craft Advisory for PKZ814. Brisk Wind Advisory for PKZ815. Brisk Wind Advisory for PKZ861.