textproduct: Fairbanks

KEY MESSAGES

Central and Eastern Interior... -Temperatures briefly warm into the upper 60s/low 70s Thursday as a ridge continues to develop. As troughing returns to the region, highs drop back into the low/mid 60s for the weekend and into next week.

-A low entering the Bering and a weak frontal system will bring 0.25- 0.5 inches of precipitation to the Interior from Fairbanks west. Another low entering the southwest Yukon will likely bring wetting rains to the Upper Tanana from Northway south. The Upper Tanana between Dot Lake and Tok has the highest likelihood of staying dry through the weekend.

-There are chances for an isolated thunderstorm or two each afternoon from Thursday through Saturday. The greatest probability and extent of thunderstorms expected on Friday afternoon, where isolated storms are possible in the entire Eastern Interior from Fortymile Country north.

West Coast and Western Interior... -Most of the region gets a brief break from the rain Thursday, with the exception of continuing shower activity in the Northwest Interior.

-A weak low arrives in the Bering on Friday, bringing with it gusty winds, locally higher tides (no flooding is expected), another round of moderate rainfall.

-Temperatures cool slightly this weekend as an Arctic trough digs into the Interior. High temperatures above 60 degrees will be few and far between Saturday and Sunday afternoon.

North Slope and Brooks Range... -Isolated thunderstorms are possible in the Eastern Brooks Range and Arctic Plains Friday afternoon as a ridge shifts east into Canada.

-Temperatures cool into the weekend as an Arctic trough digs over the North Slope. Expect highs in the upper 30s/low 40s after the front passes through, which will be Saturday west of Umiat and Sunday from Umiat east.

-A front sweeps across the slope along with the trough this weekend, bringing the potential for traces-1 inch of non-accumulating snow, with 2-4 inches possible in the Northeastern Brooks Range.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

Weak ridging is expected to build across Northern Alaska midweek, but will be short-lived as upper-level troughing is expected to build in by the end of the week. Even with this weak ridging, cooler temperatures and isolated to scattered showers are expected to persist. By Friday morning, a low will be approaching the West Coast from the Bering Sea, bringing precipitation and gusty winds. There are some slight model disagreements on the strength and track, but current guidance keeps it above 990 mb and will keep it south of St. Lawrence Island. With the current track being south of St. Lawrence Island, any coastal impacts from the southwesterly fetch of winds will be minimized. Exact rainfall totals remain uncertain, but showers will likely linger for the state Friday through the weekend with the West Coast and Western Interior receiving a bulk of the precipitation.

LONG TERM /SUNDAY THROUGH WEDNESDAY/

The extended forecast period will begin with the Bering Sea storm that moved onshore on Friday beginning to quickly move southeast towards the Gulf of Alaska. Sunday night there is good model agreement regarding an arctic trough swinging west to east across the North Slope. This trough will bring cooler temperatures and another round of precipitation. This precipitation would be rain in the Arctic Plains and Coast, but in the Brooks Range we could see it become either a rain/snow mix or just snow. Snow levels will drop to around 2500 to 3500 in the Brooks Range. We are not anticipating much on accumulations with 1 to 3 inches possible in the Central/Eastern Brooks Range.

Sunday night and into Monday, a low will begin to move into the Bering Sea. This low will be accompanied with a ridge axis that is in the Gulf of Alaska that will allow for southwesterly flow into the West Coast. This low is not expected to be strong with it bottoming out at around 990 mbs. While the winds are not expected to be strong, we could see a round of moderate to heavy rain showers across the West Coast and Western Interior. Models are struggling with how much rainfall we are expecting due tropical moisture rotating towards the Aleutian Island chain around the North Pacific High. Some models do not have this moisture phasing with this low. With not all of the models agreeing we are seeing large model spreads on the rainfall amounts. Between the 25th and 75th percentiles of the NBM there is a spread of 0.5" to 1.5" of rainfall. As this low moves northeast from Norton Sound to the Arctic Ocean, this rain will move eastwards bringing widespread rain chances across the Interior.

Mid to late week we will be monitoring how Hurricane Lala will interact with our pattern is the North Pacific Ridge steers it towards the Aleutian Islands. Models are keeping the low center out of the Bering Sea, and letting it meander in the North Pacific to eventually weaken. The moisture contents however could potentially get phased together with another low that will be rotating into the Bering Sea out of Eastern Russia. Depending on the timing of these two features we could see another low in the Bering tapping into tropical moisture bringing the chance for another round of moderate to heavy rainfall across the West Coast and Western Interior by the end of the week. There is a lot of uncertainty regarding this extended forecast, and we will continue to monitor it, but outside of the potential of moderate to heavy rainfall we are not anticipating significant impacts.

Coastal Hazard Potential... A very weak Bering Sea storm will bring higher waters to the Eastern portions of Norton Sound Friday morning during high tide. This storm could bring an additional 1 to 2 feet of water above the mean high water mark. This could create some minor beach erosion, but no flooding is expected with this system.

FIRE WEATHER

The primary fire weather concerns today will remain in the far Eastern Interior particularly the Upper Tanana Valley, as the Western/Central Interior will remain cooler and wetter. From Fairbanks west isolated to scattered rain showers will continue throughout today. The best chances for wetting rains today remain in the Koyukuk and Kobuk Valleys while the Tanana and Yukon Valleys would most likely see T-0.09". Temperatures across the Central/Eastern Interior will continue to be in the 50s/60s today and will begin to slightly cool tomorrow as troughing will begin to make a return.

In the Eastern Interior conditions will be slightly better than yesterday, with the addition of an isolated rain shower or two in the Upper Tanana Valley and isolated thunderstorms in the Fortymile Country. Temperatures across the Eastern Interior Valleys will be around 70 and minimum RH values above 40%. We will still see southwesterly downslope flow across the Alaska Range and into the Upper Tanana Valley, but cloud cover should keep temperatures and RHs moderated. There is the potential to see some marginal clearing in the clouds from 12 PM to 6 PM. These clearer skies and a weak upper-level disturbance are what will help to allow for rain showers to potentially form today. These showers will be very isolated, but if they do for we could see 0.05" - 0.15" of rainfall. Areas between Delta Junction and Northway have the best chance to see a rain shower.

Friday will mark the general cooling trend across the Eastern Interior for the next couple of days. This will be accompanied with chances for isolated thunderstorms from the Upper Tanana Valley to the Brooks Range. Yesterday models were hinting at the potential for wetting rains Friday night and Saturday across much of the Upper Tanana Valley. Models are beginning to back off significantly from that solution, and most of the rain will be from Northway to the AlCan with up to 0.25" of rain being possible. Dot Lake to Tok could see some light rain of T-0.09", but downsloping off the Alaska Range is reducing the chances for wetting rains.

HYDROLOGY

Despite recent heavy rainfall across portions of the Central Interior and Brooks Range, rivers and streams have not seen significant rises in water levels. While some smaller creeks and streams could still reach bankfull with additional showers today, no flooding is currently anticipated. An additional 0.5" to 1.0" of rainfall is possible Friday and Saturday across the Koyukuk and Middle Yukon Valleys. This rainfall could keep the water levels elevated in the smaller creeks and streams.

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. MARINE...None.