textproduct: Fairbanks

SYNOPSIS

As a ridge axis of high pressure shifts east across northern Alaska, warm and dry conditions continue for most heading through the weekend. A shortwave trough tracking northeast across western Alaska will continue to bring isolated showers for the West Coast and western Interior along with the Brooks Range/North Slope through Sunday. There is increasing confidence in the placement and strength of a low in the northern Bering Sea, which will slowly track east into northern Alaska with widespread rain and gusty winds early next week. High Wind Watches remain in effect for the Alaska Range passes and Delta Junction Sunday night into Monday and Tuesday where the strongest winds are expected. This system will be tapping into atmospheric river moisture, which will lead to moderate to heavy rainfall totals over a 48-72 hour period, focused across western Alaska and southern slopes of the Brooks Range. As this system gradually weakens towards midweek, winds will lessen as precipitation chances become more isolated to scattered. Temperatures that briefly cooled earlier in the week will hold steady or see a warming trend to finish out the week.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Warm and dry conditions will continue across much of the Interior through the weekend with plenty of sunshine. Highs will remain in the 70s to low 80s with lows in the 40s/50s.

- Isolated rain showers will be possible late Saturday into Sunday as a weak front tracks east over the Interior, but conditions are expected to remain predominantly dry.

- As a low from the Bering Sea tracks east Sunday into Monday, widespread rain and gusty winds will shift east across the Interior and Alaska Range. The bulk of precipitation is expected west of Fairbanks and in the Alaska Range, with driest conditions along the Alcan Border and Upper Tanana Valley.

- Rainfall totals late Sunday through Tuesday are expected to be around 0.10-0.25" around FNSB, T-0.10" east of Fairbanks to the Alcan Border, 0.25-1.00" northwest of Fairbanks, and 0.50-1.50" in the Alaska Range west of the Tok Cutoff.

- High Wind Watches have been issued for the Alaska Range passes and Delta Junction from Sunday night through Tuesday night for southerly wind gusts up to around 60 to 70 mph. Wind gusts elsewhere across the Interior will peak on Monday around 20 to 30 mph.

- As the Bering Sea low gradually weakens midweek, isolated to scattered rain showers will continue with temperatures that briefly cooled earlier in the week holding steady or seeing a warming trend to finish out the week.

West Coast and Western Interior...

- Warm and mostly dry conditions will continue across much of western Alaska through Saturday night, with isolated rain showers possible. Highs will be in the 60s to low 70s with lows in the 40s/50s, locally cooler along the West Coast.

- As a low in the Bering Sea tracks east Sunday into Monday, widespread rain and gusty winds will shift east across western Alaska. Steadier rain will reach St. Lawrence Island around midnight Sunday morning and West Coast throughout the day Sunday.

- Rainfall totals Sunday through Tuesday are expected to be around 0.50-1.50" regionwide, with locally higher totals up to around 2.00".

- Winds gusts will peak around 30 to 50 mph regionwide as the low moves in, with minor coastal impacts expected (primarily high surf) for communities along the West Coast.

- As the Bering Sea low gradually weakens midweek, isolated to scattered rain showers will continue with temperatures that briefly cooled earlier in the week holding steady or seeing a warming trend to finish out the week.

North Slope and Brooks Range...

- Warm and mostly dry conditions today across much of far northern Alaska will give way to increasing isolated to scattered rain showers building in tonight through the weekend out of the west. Highs will be in the 60s to low 70s with lows in the 40s/50s, locally cooler along the Arctic Coast. - While rainfall totals through the weekend are expected to remain light overall, steadier rain will move into the Brooks Range on Monday as moisture from a low in the Bering Sea tracks north.

- Rainfall totals Monday and Tuesday will be heaviest in central and eastern portions of the Brooks Range, where around 0.50-1.50" of rain is expected, focused on the southern slopes, as the North Slope gets downsloped and stays predominantly dry.

- As the Bering Sea low gradually weakens midweek, isolated to scattered rain showers will continue with temperatures that briefly cooled earlier in the week holding steady or seeing a warming trend to finish out the week.

SHORT TERM FORECAST DISCUSSION

Today through Sunday Night. Afternoon satellite imagery shows a ridge axis of high pressure shifting east over Northern Alaska as a shortwave trough and weak closed low track northeast across Western Alaska and the eastern Bering Sea. As that trough tracks northeast this weekend, isolated showers to scattered showers will follow suit, with a focus across western Alaska and the North Slope/Brooks Range while conditions remain predominantly warm and dry across the Interior. There is increasing confidence in the placement and strength of a low in the northern Bering Sea, which will slowly track east into northern Alaska with widespread rain and gusty winds early next week. By Sunday afternoon and evening, a 985-990 mb low is expected to be centered west of St Lawrence Island, with a widespread precipitation shield lifting northeast into Western Alaska. Light to moderate rain with localized bands of heavy rain will be the predominant rainfall rates, with gusty winds filling in behind the leading band of precipitation late Sunday into Monday. As this low ejects a series of fronts into northern Alaska, widespread precipitation chances will shift east into the Interior Sunday night into Monday, with the highest uncertainty centering around where the heaviest precipitation sets up in the central/eastern Interior with drier conditions favored farther east out towards the eastern Interior and Alcan Border. As winds are ramping up regionwide late Sunday into Sunday night, winds through Alaska Range passes will also steadily increase. This is where a High Wind Watch goes into effect Sunday night for gusts up to 70 mph, with a watch also in effect for Delta Junction for gusts up to 60 mph. See the long term discussion below for a deeper dive into this system.

FIRE WEATHER

Drier weather has settled across much of northern Alaska as a ridge continues across the Interior of the state. High Temperatures through the weekend will be on a warming trend as the ridge traverses east across Alaska, reaching into the 70s to near 80. The highest temperatures for the Western/Central Interior are expected Saturday while the Eastern Interior will likely see higher temperatures on Sunday. Min RHs will continue to be as low as 30% through Saturday, with some spots likely near 25%, especially in the Tanana Valley.

By Sunday, the pattern is expected to change as widespread wetting rains will be spreading across the West Coast and Western Interior, and into the Central Interior by Monday, though drier weather may linger further east between the Yukon Flats and Fortymile country. Strong southerly winds through the Alaska Range Passes are expected Sunday evening through Tuesday evening with gusts as high as 70 mph possible while areas along the West Coast and Western Interior could see gusts as high as 45 mph on Sunday. Cooler temperatures in the 60s to low 70s will arrive with this precipitation.

HYDROLOGY

An atmospheric river arriving across the western interior late Sunday into Monday will bring river rises across smaller rivers in the west and along the Alaska Range through the first half of next week. No flooding concerns are expected. Precipitation totals of 1-2 inches are looking increasingly likely from Sunday to Tuesday for these areas, with isolated higher amounts possible in areas of terrain.

LONG TERM FORECAST DISCUSSION

Monday through next Friday. Continuing from the short term discussion, the main story will be the Bering Sea low approaching northern Alaska beginning Sunday into Monday, bringing gusty winds to the West Coast, Western Interior, and Alaska Range passes. High Wind Watches have already been issued for the Alaska Range and Delta Junction Sunday evening through Tuesday evening for southerly wind gusts as high as 70 mph. The West Coast and Western Interior could also see wind gusts as high as 45 mph and is expected to peak on Monday. Wind Advisories may be issued in those areas, but that decision will be made tomorrow. With these gusty winds, high surf may be possible along coastal locations, though exact locations with water levels remain fairly uncertain.

This atmospheric river is also expected to be tapping moisture from the tropics, leading to high precipitation totals expected. Generally, rainfall totals for Sunday and Monday are expected to range as high as 1-1.5" from the YK Delta to Nome and along the Western Interior with a bulk of the rainfall along the Middle Yukon and Upper Kuskokwim Valleys where totals could reach higher then 1.5". Primarily drier conditions are expected east of and including Fairbanks along the AlCan border and across the Arctic Coast from Point Lay to Kaktovik due to the chinook flow from the Alaska Range.

As this system is winding down, it is expected to linger into Tuesday, reverting more to periods of light rain for the West Coast and Western Interior with accumulations as high as 0.25" with locally 0.5" in the higher terrain possible.

Coastal Hazard Potential Days 3 and 4... Some minor beach erosion and high surf are possible for Norton Sound and the Kuskokwim Delta Monday and Tuesday as a 985-990 mb low over St Lawrence Island sends southerly winds up across much of the West Coast. More updates will be made available this weekend as forecast confidence in a final track and strength of the low develops, which will lead to increasing confidence on exact water level rises expected in each community. Stay tuned.

AFG WATCHES/WARNINGS/ADVISORIES

AK...High Wind Watch for AKZ837-849. High Wind Watch for AKZ847. PK...Small Craft Advisory for PKZ811-857. Small Craft Advisory for PKZ812-858. Small Craft Advisory for PKZ856.