textproduct: Fairbanks

SYNOPSIS

Cold weather continues across Interior Alaska, and especially for the eastern half and within the Yukon Flats and Upper Tanana Valley, with values dropping below -50F for a few locations this morning, such as Chicken at -56F. Due to gusty winds up to around 40 to 45 mph and very cold temps, dangerously low wind chills will be felt for locations along the Yukon riverbed to the AlCan border, such as Eagle, a Cold Weather Advisory has been issued through tomorrow morning for Forty Mile Country. The North Slope by contrast is relatively warmer for today, with temperatures in the single digits and teens above zero as a round of light snow shifts eastward across the area through tomorrow morning. Thereafter, colder air moves in behind a cold front, dropping much of the North Slope into the negative teens for tomorrow. This will quickly change from Thursday through the weekend as a low from Siberia transitions over the state from west to east, bringing widespread snowfall of at least an inch, and much warmer temperatures to Alaska north of the AK Range. The colder air locked in place across much of the Interior will begin to scatter out with southerly flow and warming temperatures ahead of the approaching low pressure system for Thursday into Friday. On the North Slope, winds will increase today, which could result in blowing snow and reduced visibilities at times, especially where they combine with falling snow. Very cold conditions settling in over the region into early next week could drop temperatures into the -40s or -50s in much of Eastern Alaska, even outside typical cold spots.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Cold weather will continue across the Interior through tomorrow, and then begins to warm on Thursday into Friday. Cold valley locations will see lows in the -30s and -40s, with the Upper Tanana Valley falling to around -50F.

- Beginning on Thursday, another system will move into the area and yield snow totals widely of around 1 to 3 inches through the weekend, with higher totals of over 4 inches possible from the north slopes of the Western AK Range to the White Mountains.

- Considerably warmer temperatures are likely on Friday with this system, with highs widely rising into the positive single or double digits.

- Much colder air is going to settle back into the area, especially over the eastern half of the Interior, during the early part of next week, which may allow for even colder temperatures to be possible.

West Coast and Western Interior... - Cold weather with lows in the negative teens and 20s will continue through tomorrow night ahead of the next system.

- From Thursday through the weekend, much warmer temperatures are expected, with increasing clouds and generally around 1-4 inches of light snow.

North Slope and Brooks Range... - Light snow will continue across the eastern North Slope through tomorrow before colder air is ushered in by a cold front in its wake. Accumulations will generally be light.

- A more robust wave of snow is expected from Thursday into the weekend as a low moves along the Arctic coast. 2 to 4 inches of snow are widely possible across the area. Higher totals are possible in the Brooks Range and Arctic plains, mostly east of the Dalton Highway. Portions of the eastern Brooks Range southeast of Sagwon may also receive between 6-8 inches of snow.

- As the low moves along the coast, widespread winds of 25 to 35 mph, with higher gusts, will shift from SW to W and could combine with falling/fresh snow to blow and reduce visibilities.

FORECAST ANALYSIS AND DISCUSSION

Currently, a weak shortwave is transitioning across the North slope and providing some light snow showers. There is also an area of high pressure located over western Canada and a decaying wave with an associated area of low pressure over the Gulf of Alaska has allowed for the pressure gradient to tighten through the Yukon River and Tanana River Valleys with a low-level jet present this morning, which has been providing some strong and gusty winds for locations from Delta Junction and Eagle. Because of the strong and gusty winds up to 45 mph, coupled with the very cold actual air temperatures in place, there has been very low wind chill values down to -55 for these locations. As the gradient loosens by early tomorrow morning, these winds will begin to diminish and allow for wind chill values to also come down below the threshold. In addition, the troughing over the North Slope has allowed for winds to become stronger and gusty at times out of the southwest, and this may result in some areas of blowing snow with reduced visibilities through tomorrow. There are Special Weather Statements issued which highlight all of these details. Models have continued to display a pattern change with an area of low pressure approaching from Siberia, which will allow for a return of some more mild temperatures as southerly flow ahead of this system becomes predominant, with warming temperatures beginning Thursday evening into Friday. This will also allow for there to be a broad area of anywhere between 1 to 4 inches across most portions of the Mainland, and even higher amounts for the eastern Brooks Range, with some areas receiving up to 6-8 inches.

EXTENDED FORECAST DAYS 4-7

Ensembles have been consistent in showing a large ridge strengthening over the Bering Sea and over up into the Chukchi Sea, and this will allow for much colder air advection to be reinforced over the area. For the Interior, cold air will reconsolidates, with widespread lows down into at least the -30s and -40s F in the Central and Eastern Interior and the negative teens in the Western Interior. Early next week, models depict a strong ridge over the Bering Sea and Siberia with extensive and very cold troughing over northwestern Canada. With a large, dry, and very cold air mass aloft from Mon Dec 15 through at least Wed Dec 17, where there could be -50s felt across much of the Eastern Interior and eastern North Slope even outside of just the typical cold spots.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...Cold Weather Advisory for AKZ835. PK...Brisk Wind Advisory for PKZ814-815-861. Heavy Freezing Spray Warning for PKZ817. Heavy Freezing Spray Warning for PKZ851. Small Craft Advisory for PKZ851.