textproduct: Fairbanks

SYNOPSIS

Cool and sometimes unsettled conditions will continue as a series of systems affect Alaska over the next several days. Well below normal temperatures Tuesday will moderate back to seasonal levels as the week continues with the exception of the Northwest Arctic Coast where a taste of winter will be possible through midweek. An Arctic front approaching from the Chukchi Sea will bring a mix of rain and snow to parts of northwest Alaska through midweek. Additionally, some scattered showers will occur elsewhere late in the week and over the weekend.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Scattered showers will continue through Tuesday afternoon across the Interior, with best chances for rain and isolated thunder for the Upper Tanana and Fortymile Country.

- Below normal temps generally in the 60's will continue Tuesday with moderating temperatures back into the lower 70's for the rest of the week.

West Coast and Western Interior... - Gusty southwest winds will continue across the west coast, with speeds beginning to diminish by Tuesday evening.

- Scattered showers coming to an end this evening with additional rain chances returning Tuesday evening and Wednesday as another front approaches.

- Chilly temps in the 40's/50's near the coast Tuesday with lower 60's over the western Interior. Temps stay cool near the coast but begin to modify for locations further inland Wednesday and Thursday.

North Slope and Brooks Range.. - Snow showers will continue through this evening across highest elevations of the Brooks Range and across the Arctic Coast from Point Thomson east to Kaktovik, where a Winter Weather Advisory is in effect through 10 PM tonight for a rain/snow mix.

- Recent heavy rainfall has led to rises of rivers and streams throughout portions of the Brooks Range leading to minor flooding of Slate Creek and the Koyukuk River from Coldfoot north to Atigun Pass.

- An arctic cold front will reach the northwest Arctic coast during the day Tuesday with falling temps expected through the day. Some light mixed precipitation is likely near the coast as the front arrives. Additional rain/snow will be possible across the western Brooks Range and western North Slope Tuesday night into Wednesday.

FORECAST ANALYSIS AND DISCUSSION

A general troughing pattern looks to dominate the region throughout the short term period. This will keep somewhat unsettled conditions in place as individual closed lows and associated vort maxes pivot around the trough. Currently an upper low is situated over the YK Delta and is allowing for southwest flow into much of the Interior providing widespread cloud cover and occasional showers along with cooler than normal temperatures. In addition, a stalled frontal boundary north of the low remains over the Brooks Range where steady rainfall continues, but should be winding down later tonight as the upper support for this feature continues to shift north into the eastern Beaufort Sea. This feature is also producing a mix of winter type precipitation along the eastern Arctic coast this afternoon where a Winter Weather Advisory will remain in effect until later this evening.

The upper low over the YK Delta is progged to shift east to the upper Panhandle by midweek. This will allow for a renewed easterly push of moisture over the eastern Interior the next few days along with moderating Interior temps. This will allow for additional convective activity over the eastern Interior with scattered light showers elsewhere.

Meanwhile another upper low over the high Arctic will begin to push an Arctic front ashore along the Northwest Arctic coastline tonight and early Tuesday. Some light precipitation will accompany the front from Utqiagvik down towards Point Hope. Temperatures may be cold enough for some mixed precipitation, but overall QPF will be light, so will hold off on any winter headlines for now. However, another wave of energy will quickly drop south through the Chukchi Sea by Wednesday that will allow for some additional moisture advection over northwest Alaska for midweek. Depending on just where the previously mentioned Arctic front winds up, there may be enough cold air in place behind the front to allow for snowfall over portions of the western North Slope as well as the northern Seward Peninsula late Wednesday into Thursday.

FIRE WEATHER

Broad upper level troughing remaining in place over Northern Alaska this week will keep cloudier and cooler weather around to start to the week, as a series of closed lows rotate around relative high pressure in the Central Interior. Following a cold front that has stalled in the Brooks Range, scattered showers have filled in across the Interior and Western Alaska today, with breaks in the clouds remaining conducive for isolated thunderstorm development across the Upper Tanana, Fortymile, and Alaska Range this afternoon and again Tuesday afternoon. Breezy southwesterly winds with gusts up to 30 mph are possible for the Northeastern Interior through this evening. Winds will weaken through midweek, with lighter winds expected for a majority of the Interior Tuesday into Wednesday. The exception to this will be the Upper Tanana with northwest gusts of 20-30 mph Tuesday afternoon into Wednesday. A more organized easterly wave will build into the Southeast Interior from the Yukon tonight into Tuesday and Wednesday, supporting steadier rainfall for the Eastern Alaska Range north through the Upper Tanana and Fortymile along the Alcan Border. Rainfall amounts through Wednesday in this region are expected to be around 0.25-0.75". Outside of this region, a series of fronts building into Northwest Alaska will support several rounds of mixed precipitation for the NW Arctic Coast along with breezy winds for the Seward Peninsula and Kobuk/Koyukuk Valleys on Tuesday with gusts to around 15-25 mph. Overall, with cooler temperatures and higher RHs in place with generally showery conditions, fire weather has moderated across our region with no significant warming and drying trend expected for at least a week at this time.

HYDROLOGY

As much as 1-2" of rain has fallen across much of the Yukon Flats and parts of the Fortymile over the last 48 hours. This represents a 1 in 25 year precipitation event for some locations. As rain showers slowly diminish overnight tonight, expect continued rises and higher water, especially for the Fortymile and Slate Creek near Coldfoot. A Flood Advisory has been issued through Tuesday morning for Slate Creek at Coldfoot and the Middle Fork of the Koyukuk River at Wiseman.

EXTENDED FORECAST DAYS 4-7

Thursday through Sunday. Three upper low pressure systems linger over our region for the upcoming weekend. One low in particular, located within the Bering Sea, has the potential to produce northerly wind gusts along the Bering Strait from Thursday to Friday. Model guidance suggests that each closed low has the potential to produce light rainfall throughout the state during the extended time frame, although there is low confidence on where the precipitation will be throughout this period. Guidance also supports higher confidence in temperatures trending slightly below normal with continuing longwave troughing and cloud cover over Alaska during this period.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Winter Weather Advisory for AKZ805. PK...None.