textproduct: Fairbanks

SYNOPSIS

Winter's chill will be noticeable for much of the region tonight through Thursday thanks to the recent passage of an Arctic Front. However, this will be short lived as a disturbance over the Bering will be sending several waves of active weather into the region over the next several days. Southwesterly flow will help warm temperatures a bit, but will also allow for the arrival of abundant moisture. Strong winds and moderate to heavy rainfall will develop Thursday into the weekend, with the potential for additional precipitation early next week depending on where eventual storm tracks set up.

KEY MESSAGES

Central and Eastern Interior...

- Drier conditions behind an exiting cold front should allow for clear skies overnight and sub-freezing temps by Thursday morning for much of the Interior.

- Rain chances will be on the increase from southwest to northeast through the day Thursday as a warm front tracks northwards into the region.

- An approaching atmospheric river behind the front will bring additional rainfall Thursday night into Friday with a second push of steadier rain Friday night into Saturday.

- Expected rainfall amounts Thursday through Saturday are around 0.50 to as much as 1.50 inches for the Central Interior west of and including FNSB, and 0.10 to 0.50 inches east of FNSB. The exception to these amounts will be in the Upper Tanana Valley and Fortymile region, where conditions are expected to remain dry due to downsloping flow.

- Southwesterly flow into the Interior later this week with this system will lead to warming temperatures, as highs climb into the 50s/60s to near 70F for the Upper Tanana Valley starting Friday. Lows will also rise to the mid 30s to mid 40s.

West Coast and Western Interior...

- Atmospheric river moisture from a strong low pressure system in the Bering Sea will lift northeast across the West Coast tonight into Thursday. Widespread moderate to heavy rain and gusty winds are expected region wide with this system.

- Expected rainfall amounts through Thursday night shows around 0.50 to 1.00 inches across Western Alaska, with locally higher totals at St. Lawrence Island up to around 1.25 inches.

- Winds increase tonight and Thursday out of the E/SE, shifting to the S/SW late Thursday into Friday as winds lessen. Peaks wind gusts are expected to be around 30 to 50 mph across the West Coast (strongest at St. Lawrence Island) and 20 to 40 mph for the Western Interior.

- Southerly winds over the Bering will continue to push large volumes of water towards Alaska's West coast late Thursday through Saturday, especially for the Yukon Coast as well as the Norton Sound. High surf is possible in this area, with water levels potentially reaching 2 to 4 feet above the normal high tide, highest around Golovin and Elim.

North Slope and Brooks Range...

- Scattered rain and snow showers will continue to shift east across far Northern Alaska into Thursday along a series of cold fronts, with light additional snowfall accumulations favoring the Brooks Range.

- Temperatures will hold steady, remaining quite cool through Thursday, with highs in the 30s/40s and lows in the 20s/30s. High elevations of the Brooks Range tonight could drop to around 10-20F with wind chills down around 0-10F.

- A Bering Sea low will send a warm front into far northern Alaska late Thursday and Friday, with widespread light precipitation and warmer temperatures expected courtesy of southwest flow.

- Expected precipitation amounts late Thursday into Friday are expected to be around 0.1 to 0.50 inches in the Brooks Range, and a trace to 0.10 inches across the Arctic Coast/Plains. Light snow is also expected in the Brooks Range and Arctic Plains just north of the higher terrain.

SHORT TERM /THROUGH SATURDAY NIGHT/

Afternoon satellite imagery across Alaska reveals a couple of primary centers of circulation. One is located across the southern Beaufort where an Arctic upper closed low continues to send shortwave energy eastwards across the Arctic coastline and North Slope. While these impulses will continue to result in occasional rain/snow showers through Thursday morning, this system will get diverted to the east and weaken a bit as a north Pacific ridge pushes north into the eastern reaches of the state. Meanwhile, skies have started to clear across the Interior which will lead to maximum cooling overnight tonight. Portions of the Interior are still on track to see the first hard freeze of the season tonight, including the Fairbanks metro area.

The other visible circulation of note is located out over the Bering Sea in the form of an upper low that will quickly begin to focus impactful weather systems across the West Coast and portions of the Interior over the next several days. As of this writing, a warm front was ejecting northwards through the YK Delta and bringing widespread light to moderate rainfall. Rainfall associated with the warm front will continue to track north and east overnight and Thursday with precipitation reaching the Seward Peninsula by daybreak Thursday and expanding eastwards into the western Interior as the day progresses. Initial rainfall associated with the warm front will range from .25" across the western Interior to between .50" and 1.00" westwards towards the coast and the Bering Strait. But this is just the first wave of precipitation that the Bering low will be sending our way.

A large fetch of moisture is currently being transported northwards in the southwest flow east of the upper low. IVT products for the GFS and ECMWF both indicate a sustained influx of deep moisture into western and central Alaska through Saturday morning. While past model runs focused this moisture channel along the immediate west coast, subsequent runs have shown a tendency for the north Pacific ridge to weaken and shift eastwards a bit, channeling the moisture further eastwards into the western and central Interior. The current forecast package has followed this trend and is now placing the highest storm total QPF through Saturday over the central and western Interior. While total QPF should be in the .50" to 1.50" range over the Interior, there could be locations that actually see upwards of 2.00" of rainfall over the next few days. While there are no immediate hydro concerns, should rainfall wind up excessive over the weekend, that could change. (See hydro section below).

The other big impact from the Bering Sea low will be increased winds. Coastal winds will be strongest tonight through Thursday along the Yukon coast and through the Norton Sound. However these winds will generally be from the E/SE and initially will not cause much in the way of high water concerns. But as this flow becomes more southerly Thursday night and into the weekend, higher water may be realized in these areas, especially across portions of the northern Norton Sound. As a result, a High Surf Advisory has been issued there to account for the increase in water levels.

Coastal Hazard Potential...

A Bering Sea low and associated warm front will move into Western Alaska this evening into Thursday, with widespread rain and gusty winds expected. Water levels could rise 2 to 4 feet above the normal high tide line in the Norton Sound, and 1 to 2 feet above the normal high tide line along the Yukon Delta Coast. Water levels are expected to peak late Thursday into Friday and Saturday morning. Gusty east to southeast winds Wednesday into Thursday will shift to the south to southwest Thursday into Friday, leading to more onshore flow and the potential for higher water levels. As a result we have issued a High Surf Advisory for coastal areas of the eastern Norton Sound where guidance is showing the highest water level rises at this time.

LONG TERM /SUNDAY THROUGH WEDNESDAY/

The extended will begin on Sunday as a Bering Sea low continues to force a sustained ridge east out of our area. This system will then remain relatively stationary within the Bering Sea until a new low approaches Sunday evening. A low pressure system originating from roughly 40N moves into the Bering Sea, and it will potentially form a triple point low with the preceding Bering Sea Low. This low will bring chances of gusty winds and another round of moderate to heavy rainfall.

As the low pressure system approaches Alaska Sunday into Monday, the track remains uncertain, if the storm tracks north and enters Alaska though the YK-Delta there will be higher chances for another round of moderate to heavy rainfall to reach the Interior. Given the multiple rounds of rainfall this region will experience over the next few days, this new round of rainfall could create hydro concerns. However, if the system instead trends toward the Gulf, and approaches Alaska from the south, the moisture associated with this storm will be focused outside of our area. As of today, model guidance has suggested a northerly trend of this system. This storm's track will remain monitored until more confidence is understood on its strength and impact.

FIRE WEATHER

An exiting cold front in the Eastern Interior today will bring clearer skies and colder temperatures across the Central and Eastern Interior Valleys tonight. Temperatures will drop to the upper 20s to low 30s. Any valley location with clear skies today will most certainly drop into the 20s. Behind this front Thursday morning a ridge will quickly move over the region. Accompanied with this ridge is a Bering Sea low which will allow for southerly flow to develop over the Alaska Range.

Southerly flow is expected to begin in the Alaska Range Thursday afternoon with wind gusts up to 30 mph. These winds could potentially extend into Saturday. This chinook flow will help to keep the Upper Tanana Valley warmer and drier compared to the rest of the Central/Eastern Interior. While the Central/Eastern Interior will warm into the low 60s starting Friday, the Upper Tanana Valley could approach 70.

While a ridge will be parked over the Eastern Interior the only dry spot will be the Upper Tanana Valley. A warm front associated with the Bering Sea low will be swinging through the Central Interior Thursday night. This warm front will stall over the region keeping widespread heavy rainfall continuing through the weekend. The Central Interior including Fairbanks could see 1" to 2" of rainfall through the end of the weekend.

HYDROLOGY

A strong push of moisture across the Western and Central Interior is expected over the next couple of days. Rainfall totals 1 to 2 inches between Fairbanks, Bettles, and McGrath will be possible so expect fairly decent rises in local streams and rivers with sandbars potentially covered. Exact location of these higher amounts remain uncertain as ensemble members show a wide range of totals due to varying storm tracks, but models are currently showing the area of heaviest rainfall in the lower Tanana River Basin and the middle Yukon. If the heaviest totals shift east towards the Chena Basin, there may be concerns for FNSB.

AFG WATCHES/WARNINGS/ADVISORIES

AK...High Surf Advisory from 10 PM Thursday to 11 AM AKDT Saturday for AKZ822-824. MARINE...Small Craft Advisory until 7 PM AKDT this evening for PKZ801. Small Craft Advisory from 1 AM to 1 PM AKDT Thursday for PKZ801-805. Small Craft Advisory from 4 AM to 1 PM AKDT Thursday for PKZ802-852. Small Craft Advisory from 1 AM to 4 PM AKDT Thursday for PKZ806. Small Craft Advisory from 7 AM to 6 PM AKDT Thursday for PKZ807-856. Small Craft Advisory from 10 AM to 6 PM AKDT Thursday for PKZ808-809-855. Small Craft Advisory from 1 PM to 6 PM AKDT Thursday for PKZ810. Small Craft Advisory from 4 PM to 6 PM AKDT Thursday for PKZ811-857. Small Craft Advisory until 10 AM AKDT Thursday for PKZ816-850. Small Craft Advisory until 10 AM AKDT Thursday for PKZ817. Gale Warning from 1 AM to 7 AM AKDT Thursday for PKZ817. Small Craft Advisory until 7 AM AKDT Thursday for PKZ851. Gale Warning from 10 PM this evening to 1 AM AKDT Thursday for PKZ851. Small Craft Advisory from 10 PM this evening to 1 PM AKDT Thursday for PKZ853. Small Craft Advisory from 10 PM this evening to 4 PM AKDT Thursday for PKZ854.