textproduct: Fairbanks

SYNOPSIS

A Bering Sea low that brought widespread rain, gusty winds, and high surf along the coast to northern Alaska over the past 36 hours will continue to weaken tonight into Tuesday as another, weaker low moves onshore tonight into Tuesday into western Alaska. Best rain chances and strongest winds will shift to being west of Fairbanks for Tuesday and Wednesday, primarily across the West Coast, western Interior, and southern slopes of the Brooks Range, as another system and associated front moves in from the Bering Sea. Winds will also remain elevated through Alaska Range passes through Tuesday, with gusts up to around 65 mph. Warmer and drier conditions will return to the North Slope and central/eastern Interior Tuesday into Wednesday as southerly downsloping flow off the Alaska Range and Brooks Range leads to warming and drying conditions. Broad troughing in the west and ridging in the east will both shift east later this week, allowing for scattered showers and cooler conditions farther west to build east across the Interior later this week.

KEY MESSAGES

Central and Eastern Interior...

- Cooler temperatures across the Interior today as a Bering Sea storm brings cloud cover and rain showers. Temperatures will return to the mid 70s Tuesday afternoon.

- Steadier rain in the morning and early afternoon will become more showery in the afternoon hours.

- Areas of wildfire smoke will continue to potentially impact the Fairbanks area into Tuesday, following a very active day on the Tatlanika Fire about 40 miles south of Fairbanks on Sunday which led to ash falling across portions of the FNSB Sunday night into Monday morning.

- Additional rainfall totals through Tuesday are expected to be around 0.10-0.25" around FNSB northeast across the Yukon Flats, T-0.1" east of Fairbanks to the Alcan Border, 1.0-2.0" northwest of Fairbanks, and 0.5-1.5" in the Alaska Range west of the Tok Cutoff.

- A Wind Advisory remains in place for southerly wind gusts have been issued for the Alaska Range passes through Tuesday night for gusts up to 65 mph. Wind gusts elsewhere across the Interior will peak on Monday around 20 to 30 mph.

- Precipitation will become more showery on Tuesday and Wednesday as drier and warmer conditions prevail due to persistent southerly flow over the Alaska Range.

West Coast and Western Interior...

- A Bering Sea low is continuing to bring widespread gusty winds and moderate to heavy rainfall to the region. The low peaked in intensity this morning, and has begun to slowly weaken and stall.

- So far this storm has produced 1-2" of rainfall across the region, locally higher across higher elevations. There will be a brief lull in precipitation as the current warm front moves east out of the region. Another front will bring an additional 0.5" to 1.5" of rainfall Monday night through Tuesday.

- Winds gusts will peak around 30 to 50 mph regionwide as the low moves in, with minor coastal impacts expected for communities along the West Coast. A High Surf Advisory has been issued for the YK Delta Coast and now additionally for the southern Seward Peninsula Coast including Nome where the highest surf is expected.

North Slope and Brooks Range...

- Temperatures will be slightly cooler as a front moves through the region bringing rain. Daytime highs will be in the 60s/70s with locally cooler conditions on the coast. Temperatures will trend warmer starting on Tuesday with highs in the 60s to mid 70s.

- With the approaching front there will be a round of rainfall today. North of the Brooks Range rainfall amounts will be light with a T-0.1" expected. The Brooks Range however could see 0.25" to 1" of rainfall, locally higher around 1-2" for southern slopes of the western Brooks Range.

- Winds will ramp up through the Brooks Range tonight into Tuesday, with gusts of 30-40 mph possible across higher elevations to include Anaktuvuk and Atigun Passes.

- After the front moves over the coastal communities later this afternoon, onshore flow will return bringing chances for fog and low stratus again Monday night.

SHORT TERM FORECAST DISCUSSION

Today through Wednesday Night. Early afternoon satellite imagery shows a pair of low pressure systems out off the West Coast, one in the Chukchi Sea that was the primary storm center of the storm impacting Alaska currently, and another in the Bering Sea near St. Lawrence Island. As that low farther north dissipates its energy and is incorporated into the low by Gambell and Savoonga, this will allow for another front to build into western Alaska tonight into Tuesday with widespread rain and continued gusty winds. There will be a brief lull in precipitation farther west as the current warm front moves east, with an additional 0.5" to 1.5" of rain expected Monday night through Tuesday across the West Coast, western Interior, and southern slopes of the Brooks Range. Elsewhere across northern Alaska, precipitation will become increasingly showery tonight into Tuesday as southerly downsloping flow ramps up over the Brooks Range and Alaska Range. This will cutoff the moisture transport into the central/eastern Interior and North Slope and with downsloping, will lead to warming and drying conditions through midweek.

Winds will remain strongest through Tuesday across western Alaska, higher elevations of the Brooks Range, and through Alaska Range passes. Peak gusts will continue to be around 30-40 mph across western Alaska with gusts up to 65 mph through the Alaska Range. The pressure gradient along the Alaska Range should peak from 10 AM to 4 PM today with a gradient of 8-10 mb. This will allow for us to see 65 mph winds in the passes. While the pressure gradient slacks after 4 PM today, the low will bring a series of mountain waves through late Tuesday to help keep the winds elevated ahead of winds dropping off for Wednesday. Winds will remain elevated along the West Coast and across the western Interior for Wednesday with gusts peaking around 25-35 mph.

Out across the southeast Interior, warmer and dry conditions will continue for the Upper Tanana Valley and Fortymile Country through midweek. Highs here in the 70s on Monday will expand north to the Yukon Flats and Arctic Plains, with some locations climbing to the 70s to low 80s. Considered a Heat Advisory for the Arctic Plains on Tuesday and Wednesday as highs climb into the mid 70s, but have held off for now given marginal temperatures. The warmest temperatures across the North Slope will be near Umiat to the Dalton Highway north to Deadhorse with highs in the 60s to mid 70s. Elsewhere, temperatures look to stay below any advisory issuance criteria of 85F. Out across western Alaska, highs will remain in the 50s/60s.

LONG TERM FORECAST DISCUSSION

Thursday through Sunday. On Thursday, the remnant of the low pressure system that brought heavy rain to Western Alaska will have stalled and weakened over the West Coast. Despite being cut off from the plume of moisture in the Pacific, it looks like it will deliver another quarter to half an inch of rain in parts of the Western Interior before dwindling into light showers for the weekend. Those light showers won't all be in the west though. The Central and Eastern Interior will be kept warm and dry under a ridge on Thursday. However, an Arctic trough descends from the north Thursday night to usher the low eastward across Alaska. The strength, positioning, and speed of the Arctic trough, and its interactions with the weak low, are still uncertain leading to differences in Interior temperatures and rainfall amounts. The ECMWF currently favors a more 'aggressive' solution, with the trough arriving sooner on Friday morning and pushing the low along the Brooks Range and out of the northeast by Saturday morning. In this solution, more widespread rain hits the West Coast and North Slope Friday afternoon, and the track of the low means fewer showers in the Eastern Interior. The GFS however, has the trough remain much farther north. With less of an influence, the low meanders more slowly on its path across the middle of the state. Light showers linger in the Interior through Saturday. Instead of a trough, a low from Siberia delivers rain to the West Coast on Saturday. The Canadian model seems to land somewhere in the middle of these two. Clustering analysis has me leaning towards the slower GFS and Canadian solutions, with half of the ensemble solutions for the GEFS and GEPS showing troughing over western Alaska on Friday. Regardless, common features between solutions include more rain on deck for the West Coast this weekend, and temperatures in the Interior cooling beyond Thursday as the low moves over the area.

FIRE WEATHER

A large, very wet, low pressure system brings widespread wetting rains to the West Coast and the Western and Central Interior as well as gusty southerly winds across the West Coast, Western Interior, and over the Alaska Range. This low settles Monday over the Norton Sound area and slowly weakens in place through Thursday. The heaviest precipitation is expected Monday with steady rains expected to turn more showery late Tuesday into Wednesday. Rain showers remain over the West Coast and Western Interior through much of the rest of the week as the remnants of the low still linger over the West Coast. Gusty southerly winds across the West Coast/Western Interior in the 30 to 40 mph range are expected through early Tuesday. Funneling through the Alaska Range passes will allow even stronger winds with gusts up to 70 mph through those passes.

Areas just north of the Alaska Range in the southern portions of the Tanana Valley and much of the Fortymile Country will see significantly less rain as the large amount of southerly flow over the Alaska Range creates a dry layer that the rain would need to overcome first. Due to the presence of strong winds and lack of wetting rains these areas see the worst conditions early this week.

As the low weakens extremely isolated thunderstorms become possible across the Western Interior Tuesday, spreading into the Central Interior Wednesday, and farther east to cover much of the Interior by Thursday. Heavy rains from this system will leave the fuels in much of the Western and Central Interior quite damp, limiting the potential for new starts.

Temperatures for the week bottom out Monday due to the low and its rain. Temperatures are expected to slowly warm through the end of the week as the low weakens and conditions return more towards their seasonal norm.

HYDROLOGY

A low in the Bering Sea is continuing to move widespread moderate to heavy rainfall into the Western Interior and southern slopes of the Brooks Range. Over the past 24 hours there has been 1" to 3" of rainfall reported across the West Coast and Western Interior. An additional 0.5" to 1.5" of rainfall is expected over the next 24 to 36 hours. No flooding is currently expected, but river rises are anticipated and smaller creeks and streams could become bankfull.

COASTAL HAZARD POTENTIAL

Gusty southerly winds from a Bering Sea low will result in higher surf along the West Coast. Water will rise 1 to 4 feet above mean high tide, with the highest water peaking Monday afternoon into Monday night during high tide. These higher waters will remain elevated even during the low tide overnight Monday, by the Tuesday afternoon high tide water levels will begin to decrease. High Surf Advisories remain in effect for the Yukon Delta Coast and now also include Nome and the southern Seward Peninsula Coast through Monday night into Tuesday.

AFG WATCHES/WARNINGS/ADVISORIES

AK...Wind Advisory for AKZ847-849. Wind Advisory for AKZ829-830-852. High Surf Advisory for AKZ822. High Surf Advisory for AKZ825. PK...Gale Warning for PKZ801. Gale Warning for PKZ802. Small Craft Advisory for PKZ803>805-809-852. Small Craft Advisory for PKZ806-853. Small Craft Advisory for PKZ810. Small Craft Advisory for PKZ811. Small Craft Advisory for PKZ812-851-858. Gale Warning for PKZ850. Small Craft Advisory for PKZ854. Small Craft Advisory for PKZ855.