textproduct: Fairbanks

SYNOPSIS

A broad upper level trough continues to remain anchored over Alaska through the remainder of the week and the weekend, keeping chances of rain and sometimes breezy conditions throughout much of the area, with more isolated showers and a few thunderstorms along the North Slope. A system and its associated fronts is currently pushing across the area through the remainder of Tuesday and into Wednesday. Following it is another organized wave which arrives Thursday and lasts through the duration of the week, although this second system will not be as strong as the first. Precip chances will be trending downwards through the weekend, with Chinook winds across the Alaska Range and warmer temperatures for the eastern interior a possibility as we head into next week.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- More widespread showers Tuesday night into Wednesday. In the wake of the front, an isolated storm east of Fairbanks or between the 40 mile area and Alaska Range is possible Wednesday afternoon. More chances of rain arrive late in the week.

- Winds are increasing through the Alaska Range and will persist through Wednesday as a stronger front moves through.

-Gusts of up to 75 mph in Isabel Pass are likely, prompting a High Wind Warning which lasts through Wednesday morning. -Up to 65 mph will be possible for Windy Pass, prompting a Wind Advisory to be issued to early Wednesday morning as well. -Another Wind Advisory has been issued for Delta Junction to Wednesday morning for wind gusts as high as 60 mph.

-A Special Weather Statement has been issued for the southern slopes of the eastern Alaska Range for wind gusts as high as 45 mph.

-Temperatures remain seasonably cool, with highs in the 60s to near 70, with the warmer temperatures towards the ALCan Border and Fortymile Country.

West Coast and Western Interior...

- Expect high temperatures in the 50s with low 60s possible by the end of the week.

North Slope and Brooks Range..

-Highest rain totals now through Thursday are expected to be on the southern slopes of the Brooks Range, especially the central and eastern Brooks Range, ranging 0.25-0.75" with localized 1.00" at higher elevations.

-There is a possibility for a period of freezing drizzle, or even freezing rain, Wednesday night into early Thursday morning, as low temperatures reach the lower 30s.

-Isolated chances of thunderstorms linger today (Tuesday) for the Arctic Plains, and especially for the eastern Brooks Range.

-High temperatures in the widespread 60s to possibly near 70 in the eastern Arctic Plains today diminish to the 50s and 60s beginning Wednesday through the rest of the week.

FORECAST ANALYSIS AND DISCUSSION

A longwave upper level trough looks set to remain persist through the remainder of the week. Multiple stronger shortwaves rotating around the broad trough axis have been responsible for rounds of precipitation and windy conditions across much of the interior. In particular, wind gusts have approached 65 mph in places like Isabel Pass. Rain totals for parts of the southern Alaska Range have reached ~4 inches, with portions of the west coast and western interior approaching or even exceeding an inch. The enhanced rain and wind with this system will remain through the day on Wednesday before diminishing late Wednesday night as the main low moves E into the Yukon; another 1-2 inches of rain are possible for parts of the southern Alaska Range, with an additional 0.25 to 0.5 inches for the West and up to an inch along the Brooks Range. A lingering shortwave spinoff over the NE Arctic Plains will contribute to a chance for some freezing rain or drizzle, although any accumulations will be minor at best.

Although shower chances will diminish on Thursday, mainly for areas from the western Interior and Yukon Flats down towards the Alaska Range, the reprieve will be short-lived. Another system is set to swing up from the the Aleutians. While the actual isobaric strength of the low - around 1008 mb per GFS guidance, is less than impressive, the system does have a respectable round of moisture with it. PWAT values along the eastern flank of the system will reach ~100 gm/kgs. Although much of the rain with this next system will be absorbed by the Alaska Range, do expect the potential for some more widespread rain showers to reach into the YK Delta on Thursday and the rest of the interior Thursday night into Friday. For additional information, refer to the long range forecast discussion.

FIRE WEATHER

As a broad longwave trough sets up shop across the Bering, it will continue to steer moist disturbances into the state, with the primary question on how far wetting rains can penetrate into the Eastern Interior. Anticipate excellent rainfall from Galena/Ruby southwest to the lower Yukon, with some guidance highlighting the potential for 0.50 to 1 inch of rain by Thursday morning. For the Central/Eastern Interior, ensemble 10 th percentiles suggest near 0.30 inches for Bettles/Allakaket with near 0.05 to 0.10 for the Yukon Flats by Thursday morning. Shifting focus into the Tanana, gusts to 60 mph have already been observed Tuesday but extensive cloud cover has limited RH/ fire potential for areas downwind of major passes. As winds diminish slowly Wednesday, isolated thunderstorms are anticipated for the Whites into Fortymile.

The only game in town right now appears to be the Yukon Flats and Tok/Northway, where we see some clearer skies and higher potential for some drying into Tuesday evening; however, light rains arrive Wednesday limiting the fire environment.

Attention turns to the long range, where we continue to see broad troughing along the western portion of the state certainly suggesting continued wetter/cooler conditions for WCZ. There is some coherent signal for southerly flow and ridging once again across the Yukon/NW Territories of Canada, bringing the potential for continued warming and some drying for the Tanana and Yukon Flats. The limitation is the persistence of the ridge, and anomalously high moisture riding up from the southeast, with most long-range ensembles suggesting a quick breakdown with the return of moist SW flow.

Simply put, while we could see some resurgence of initial attack activity in the east, most of the state will start to wind down as a fall pattern begins to take hold.

HYDROLOGY

Another 1-2 inches of rain remain possible for the southern Alaska Range through early Thursday. Some stream and river rises are likely, but flooding is not expected.

EXTENDED FORECAST DAYS 4-7

Friday through Tuesday.

Ensemble guidance has converged on a solution for the early weekend that does not favor ridging building into the Eastern Interior, keeping conditions cooler than normal and showery through the weekend in the region. This should change come next week, as a majority of both deterministic and ensemble solutions are in agreement that ridging will build into the Central/Eastern Interior early next week. Though there are variations in the position of the ridge in the solutions, most have the ridge axis tilted northwesterly, vaguely following the Yukon/Northwest Territories border into the Arctic Ocean. This pattern will result in southerly flow over the Alaska Range, bringing the potential for another round of gusty winds in the Alaska Range passes Sunday through Tuesday. As ridging is able to build into the Central and Eastern Interior, summer-like conditions will return with highs in the 70s and isolated thunderstorm activity in the Interior. Troughing is expected to remain over the western half of the state through the end of the period, keeping more fall-like conditions, including cooler temperatures and showery/windy conditions on the West Coast and in the Western Interior through at least the beginning of next week.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...High Wind Warning for AKZ849. Wind Advisory for AKZ837. Wind Advisory for AKZ847. PK...Small Craft Advisory for PKZ801. Small Craft Advisory for PKZ804. Small Craft Advisory for PKZ806. Small Craft Advisory for PKZ850.