textproduct: Fairbanks

SYNOPSIS

Active weather continues for portions of Northern Alaska as numerous weather systems are bringing snow, wind, extreme cold, or a mix of the three to the region. Cold Weather products are in effect for the Brooks Range and North Slope as wind chills in the -50 to -75 range continue over the next several days. Blizzard conditions are ongoing along the Arctic coast through this evening before conditions briefly subside. Blowing snow and windy conditions redevelop again Tuesday and Wednesday. Along the west coast, a prolonged high wind event is underway with northerly to northeasterly wind gusts of 60-75 mph right along the Coast and through the Bering Sea. Quiet and cold conditions continue in the Interior as the polar low keeps an arctic airmass in place. Further southeast within the Alaska Range Passes and Upper Tanana Valley, expect accumulating snow to increase in coverage over the next 24-30 hours as pacific moisture is drawn up from the southeast. The overall weather pattern becomes more benign towards the end of the week and into the weekend as the arctic airmass in place moves well to the west allowing temperatures to warm back to normal with little chances for precipitation.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Winter weather headlines posted for the eastern Alaska range passes and Upper Tanana Valley Monday and Tuesday as snow increases from the southeast. Highest accumulations within Alaska range passes.

- Temperatures trend colder through Wednesday with coldest valley locations reaching down to -30F to -45F

- Winds ramp up across higher elevations, peaking on Tuesday and Wednesday as a Tanana Valley Jet sets up near Delta Junction and southerly gap winds increase through Alaska Range Passes.

- Warmer temperatures build in mid to late week, returning to more seasonal levels

West Coast and Western Interior...

- A prolonged high wind event ongoing across Western Alaska, with wind gusts of 45-70 mph becoming widespread along the West Coast and in the Bering Strait where High Wind Warnings are in effect. - Temperatures plummeting back below zero through Thursday with lows -10F to -30F and even colder wind chills.

North Slope and Brooks Range...

- Near Blizzard wind down this evening along the northeast Arctic Coast; however northeasterly winds increase to 25-40 mph with higher gusts Tuesday and Wednesday resulting in blowing snow and reduced visibility at times.

- A prolonged high wind event continues for the NW Arctic Coast with gusts up to 60-70 mph through Thursday. Near Blizzard conditions at times from Kivalina to Cape Lisburne.

- Widespread double digit below zero temperatures expected to fill in regionwide through midweek. Coldest locations are expected to drop to around -30F to -50F.

- Cold Weather Advisories and Extreme Cold Warnings include all of the Brooks Range and North Slope through Wednesday for wind chills as cold as -55 to -75F.

FORECAST ANALYSIS AND DISCUSSION

A complex synoptic set up is responsible for the extreme weather across much of Northern Alaska this week. A sub 500mb upper polar low traverses the state from Mackenzie Bay to the Bering Sea over the next several days keeping the very deep Arctic airmass in place before shifting it westward by the end of the week. At the surface, an intense 1060mb+ high exists over the Arctic while a weak area of low pressure responsible for blizzard conditions today along the arctic coast dissipates as it hits the Brooks Range tonight. Lower pressure moving northward into the Gulf of Alaska tightens the northerly pressure gradient over the state, prolonging the high wind event over the west coast and arctic while increasing moisture and clouds over the Alaska Range and Tanana Valley.

Temperatures: A deep arctic airmass currently sits over the state with 850mb temperatures as low as -35C to almost -40C along the North Slope. The coldest day of the week will be Tuesday as the Polar low becomes directly overhead. With the exception of the far eastern and SE Interior, mainly clear skies over much of Northern Alaska should allow for temperatures to plummet tonight into the -30F to -50F range. Lower confidence exists in Fairbanks temperature forecast for tonight and for areas further southeast where thicker cloud cover is. Still thinking temperatures will plummet around Fairbanks, but cloud cover may help moderate temperatures somewhat over the next 24-36 hours. As the Polar low shifts to the Bering on Wednesday, southerly flow on the backside of this helps kick out the arctic airmass with 850mb temps rising to +3C to -10C by Wednesday night. Low lying interior valleys and the West Coast likely hold onto the more extreme cold through Thursday; however the eastern half of the state significantly warms up to near or above zero by the end of the week, with near to above normal temperatures persisting into the extended.

Winds: As mentioned above, an anomalously strong 1060mb+ Arctic high has created an exceptional northerly pressure gradient over the state, leading to dangerous wind chills through the Brooks Range and a prolonged high wind event along the West Coast and Bering. As the high settles in over the Arctic, expect a round of strong Northeasterly winds to set up all along the Arctic Coast Tuesday into Thursday potentially resulting in periods of blizzard conditions. The NW Coast has already been dealing with near blizzard conditions at times due to blowing snow, with the threat continuing for several more days. Strong northerly flow continues into Wednesday through the Bering as lows coming up into the Gulf of Alaska further strengthen the pressure gradient. The Cold airmass in place combined with high winds has prompted widespread Cold Weather and Extreme Cold products for all of the Brooks Range where wind chills may be as low as -75F at times.

For the Alaska Range, southerly flow sets up Tuesday into Wednesday on the backside of the Polar low. At 700mb, a strong 60-70kt jet set up over the Alaska range, helping to kick out the arctic airmass in place, but also increase winds through Alaska range passes where winds may gust to 60 mph at times along the summits. Watching Isabell Pass for the potential for at least Advisory level winds. Confidence is lower at the moment if they will reach 50 mph however still expect breezy conditions going into Wednesday. Gusty conditions extend to Delta Junction as the Tanana Valley jet briefly develops.

Snow: Focusing on the Alaska Range and Upper Tanana Valley for accumulating snow through Tuesday as numerous winter weather advisories and warnings have already been issued. Aloft, a quasi- stationary mid and upper level boundary on the south side of the Polar low remains in place and is the focus for snow shower development today in this area as Pacific moisture. Flow aloft has already turned southerly in the SE Interior allowing pacific moisture to flow up and over the boundary. Satellite imagery clear shows an E-W oriented band of clouds and snow from Palmer to Northway and into the Yukon. Expect this band to pivot, becoming more N-S oriented as the Polar upper low shifts westward; however this will only increase southeasterly flow into the Alaska range and Tanana Valley and keep snow in this region. A strong wave currently in the Gulf of Alaska heads northward by tomorrow, further helping to increase snow coverage and intensity in the Alaska Range. A foot of snow or more is possible at higher elevations of the Alaska range while 3 to 7 inches is possible in valleys and within the Upper Tanana Valley. Downsloping on the northside of the Alaska range should prevent areas further north into the Interior and around Fairbanks from receiving much snow. However, as energy pushes northwestward into the Eastern Interior Tuesday and Wednesday, expect snow shower activity to overspread the region, especially in areas that are not downsloped off the Alaska Range.

EXTENDED FORECAST DAYS 4-7

A fairly benign weather pattern sets up for the end of the week and through the weekend. The polar low responsible for the arctic air pushes off into Russia while weak upper ridging extends from Northwest Canada into the Interior. The trajectory and orientation of the ridging overhead should keep the numerous waves and lows in the Gulf in southern and southwest Alaska. Easterly/southeasterly flow persists at the surface into the weekend with well above normal 850mb and surface temperature anomalies. Will still have to watch the Arctic Coast and Bering Sea for strong winds through the period resulting in blowing snow at times. The majority of the interior is expected to remain dry and relatively mild under the influence of weak ridging aloft.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...High Wind Warning for AKZ801. Cold Weather Advisory for AKZ809>812. Winter Weather Advisory for AKZ849. Winter Storm Warning for AKZ850. Extreme Cold Warning for AKZ813. Winter Weather Advisory for AKZ815. High Wind Warning for AKZ820-821-827. Cold Weather Advisory for AKZ803>805-808. Cold Weather Advisory for AKZ832. Winter Storm Warning for AKZ832. Winter Weather Advisory for AKZ836. Blizzard Warning for AKZ805. Extreme Cold Warning for AKZ806-807. PK...Brisk Wind Advisory for PKZ801>805-813>815-852-858-859-861. Gale Warning for PKZ806-807-856. Brisk Wind Advisory for PKZ808. Brisk Wind Advisory for PKZ809-860. Gale Warning for PKZ810-857. Gale Warning for PKZ811. Brisk Wind Advisory for PKZ812-855. Gale Warning for PKZ816-817-851-854. Gale Warning for PKZ850. Gale Warning for PKZ853.