textproduct: Fairbanks

SYNOPSIS

High pressure will continue to build into northern Alaska today with warmer and dry conditions, leading to a cool morning with lows in the 30s/40s followed by highs in the 60s/70s for most. The exception to dry conditions will be across southwest Alaska, as a low pressure tracking southeast today will support rain showers south of the Seward Peninsula across the Y-K Delta and far southwest Interior. A cold front remains on track to work southeast out of the Chukchi Sea later today, reaching Northwest Alaska this afternoon and evening. This front will support an organized band of precipitation and breezy winds passing northwest to southeast across our region tonight into Sunday and early Monday, with a rain/snow mix expected for the Brooks Range north to the Arctic Coast. The heaviest snow accumulations will be on Sunday into Sunday night across northern slopes of the Brooks Range, where around 3-6" of snow is expected for Atigun Pass north to Toolik and Ice Cut Hill, with around 1-3" for Anaktuvuk Pass. Any snow totals farther north will be up to a T-1". Cooler temperatures will accompany and fill in behind the front as it passes overhead, ahead of increasing high pressure building in towards midweek with warmer and drier conditions. A secondary cold front looks to push south Wednesday and Thursday, with another round of precipitation and breezy winds.

KEY MESSAGES

Central and Eastern Interior...

- Following a cool morning in the 30s/40s, today is shaping up to be a beautiful day across the Interior. Expect dry conditions, highs in the 60s to low 70s, light winds, and plenty of sunshine.

- A cold front working southeast over the Brooks Range with pass over the Interior later in the day Sunday into Monday, with scattered rain showers, isolated thunderstorms, breezy winds, and cooler temperatures.

- Rainfall totals later Sunday into Monday are expected to remain light overall, with up to around 0.10-0.20" for most locations. Isolated thunderstorms will be possible during the afternoon and evening hours both days, favoring the higher terrain between the Yukon Flats and Tanana Valley.

- Highs in the 60s to low 70s over the weekend will cool behind the front for Monday to the 50s/60s. Increasing high pressure building in towards midweek will lead to warming and dry conditions for Tuesday and Wednesday as highs return to the 60s to low 70s.

- Another cold front is expected to track southeast over the Interior late Wednesday into Thursday with scattered rain showers and breezy winds.

West Coast and Western Interior...

- A weak low moving across southwest Alaska today will support isolated to scattered light rain showers for the Yukon Delta and far southwest Interior as dry conditions prevail elsewhere under increasing high pressure. Areas of low stratus and fog will continue across western Alaska today, particularly in the Kobuk Valley and along the West Coast.

- Temperatures this weekend will be warmest today with highs in the 50s/60s to low 70s, trending cooler for Sunday as a cold front works southeast from the Chukchi Sea tonight into Sunday, bringing scattered rain showers and gusty winds.

- Rainfall totals tonight through Sunday night are expected to remain light overall, with up to around a T-0.10" for most locations, locally higher across the Kobuk Valley and northwest Arctic Coast around 0.10-0.40" with higher totals up in the Brooks Range.

- Warmer and drier conditions will return for Monday and Tuesday with increasing high pressure, with another cold front on track to move into northwest Alaska Wednesday into Thursday with scattered rain showers and breezy winds.

North Slope and Brooks Range...

- Following a cool morning today in the 30s/40s, highs will climb into the 50s/60s for most with low 70s around Deadhorse and the Arctic Plains, as high pressure leads to dry conditions through this afternoon.

- Winds will increase today west to east ahead of a cold front moving in from the Chukchi Sea. Strongest winds today are expected along the Northwest Arctic Coast with gusts up to 45 mph. Wind gusts up to around 40 mph will shift into the Brooks Range and Eastern Arctic Coast throughout the day Sunday into Sunday night as lighter, albeit still breezy winds, fill in behind the front.

- A cold front tracking northwest to southeast from the Chukchi Sea will move into the central/western Arctic Coast this afternoon and evening with widespread rain, shifting east tonight into Sunday.

- As much colder air builds in on the backside of the front, a changeover from rain to all snow is expected for the eastern North Slope and central/eastern Brooks Range Sunday morning and afternoon. Pockets of freezing rain and sleet look to remain minimal.

- The heaviest snow accumulations will be on Sunday into Sunday night across northern slopes of the Brooks Range, where around 3-6" of snow is expected for Atigun Pass north to Toolik and Ice Cut Hill, with around 1-3" for Anaktuvuk Pass. Any snow totals farther north will be up to a around a T-1".

- Rainfall/snow water equivalent totals through Monday will be around 0.10-0.25 regionwide, locally higher across the southern Arctic Plains and in the Brooks Range around 0.25-0.75".

- Dry conditions will return west to east Sunday into Monday as initially cooler temperatures see a warming trend through midweek. A secondary cold front remains on track to move in Wednesday into Thursday with scattered showers and gusty winds.

SHORT TERM FORECAST DISCUSSION

Today through Monday Night.

Early morning satellite imagery shows a southwest to northeast oriented ridge of high pressure over northern Alaska, with one low centered in the Northwest Territories and another over the Bering Strait. Farther north across the high arctic, a deep and very broad polar low remains centered around 85N. Any rain/snow from yesterdays cold front across the eastern Interior and North Slope has shifted into northwestern Canada today, with dry and warmer conditions expected regionwide today for most. The only exception to these drier conditions will be out across Southwest Alaska where that low centered over the Bering Strait will track southeast towards the Alaska Peninsula and Kodiak today into tonight with scattered light rain showers. Light rain will remain focused south of the Seward Peninsula down towards the Yukon Delta and far southwest Interior.

An arctic trough will be ejected from that main polar low in the high arctic today into Sunday, with a cold front expected to track southeast out of the Chukchi Sea across northern Alaska with an organized band of precipitation and gusty winds. Winds have already begun to ramp up from the Bering Strait north to Point Hope and Point Lay where wind gusts around 30-50 mph have been observed. This stronger wind field will expand as the front traverses the state, with precipitation first reaching the northwest Arctic Coast this afternoon and evening. This organized band of rain will push southeast tonight into Sunday, as much colder air fills in on the backside of the front, particularly for the Brooks Range and across the North Slope. As a result, a changeover from rain to all snow is expected for the eastern North Slope and central/eastern Brooks Range Sunday morning and afternoon. Pockets of freezing rain and sleet look to remain minimal.

The heaviest snow accumulations will be on Sunday into Sunday night across northern slopes of the Brooks Range, where around 3-6" of snow is expected for Atigun Pass north to Toolik and Ice Cut Hill, with around 1-3" for Anaktuvuk Pass. Any snow totals farther north will be up to a around a T-1". The speed of the front will be the main driver of snow amounts in this corridor, with a slower track favoring heavier snow and a quicker track favoring less. The latest ECMWF actually develops a weaker closed low over the eastern North Slope late Sunday into Monday, which would further accumulating snow chances into Monday. Our latest forecast aligns closely with the 50th percentile NBM solution, with a 90% percentile forecast showing up to around 8" possible from Galbraith to Toolik. A Winter Weather Advisory may be needed for this corridor to highlight the increasing confidence of heavier accumulating snow, which coupled with gusty winds, could lead to hazardous winter travel conditions. Stay tuned.

Elsewhere across our region, we will keep rain as the predominant precipitation type, with that organized band of rain shifting southeast throughout the day Sunday into Sunday night and early Monday. Winds accompanying the front will be strongest for the NW Arctic Coast today, shifting into the Kotzebue Sound, Brooks Range, and Eastern Arctic Coast with peak gusts to around 30-45 mph expected in these corridors. Elsewhere, wind gusts will peak around 20-30 mph. Isolated thunderstorms will be possible across the Eastern Interior during the afternoon and evening hours Sunday and Monday, favoring the higher terrain between the Yukon Flats and Tanana Valley.

Broad upper level troughing in the wake of the front on Monday will keep temperatures cooler across northern Alaska with highs in the 50s/60s for most with some 30s/40s farther north. High pressure will then begin to lift northeast Monday night into Tuesday with warmer and drier conditions heading towards midweek. More on that below.

Coastal Hazard Potential Days 1 and 2...

While a cold front moving southeast from the Chukchi Sea Saturday night into Sunday will bring gusty northwesterly winds across the Kotzebue Sound tonight into Sunday, water levels are now only expected to climb as high as 1 foot above the normal high tide line across the Kotzebue Sound as opposed to the up to around 2 feet that was previously forecast. Minimal coastal impacts are expected other than high surf for some areas in this corridor.

LONG TERM FORECAST DISCUSSION

Tuesday through Friday.

At the start of the extended forecast period Tuesday, the overall pattern is dominated by 3 main features: a very large upper level low near the North Pole, a building ridge in the Bering Sea, and a low in the Gulf of Alaska that stretches a trough to the North Pole low. Tuesday there is high confidence in benign weather for the region between these 3 features. Wednesday however is where confidence begins to falter and forecasts begin to diverge. A front moving around the North Pole low approaches the region Wednesday into Thursday. The ridge in the Bering also attempts to push east into the West Coast/Western Interior. As a result there is significant model disagreement about the strength, timing, and southward extent of the front that is expected Wednesday through Thursday. A stronger front would push precipitation and gusty winds south of the Brooks Range across much of the West Coast and Interior and would limit the expected warming and drying of the approaching ridge. A weaker front would limit much of the precipitation and gusty winds to the Brooks Range and North Slope, and allow the ridge to push farther into the Interior warming and drying the region somewhat.

After the front passes through confidence in the forecast increases somewhat with pressure likely to increase across the Interior late in the week. There however remains the chance that yet another low rotates around the North Pole low and towards the West Coast which would bring yet another round of wind and rain to parts of Northern Alaska next weekend. Currently the higher pressure forecast seems more likely bringing clearer and calmer conditions, but rainy and gusty is still possible.

Coastal Hazard Potential Days 3 and 4...None

FIRE WEATHER

The Interior will see a slight increase in favorable fire weather conditions this weekend as a ridge sets up between systems. By Saturday morning, rainy and cloudy weather will depart to the east, allowing skies to clear over most of Interior Alaska. Temperatures in the Interior on Saturday will climb into the upper 60s and low 70s, but the hottest region may be the eastern North Slope where temperatures could reach the mid 70s all the way to the coast thanks to downsloping southerly winds off the Brooks Range. Relative humidity will be lowest in the Interior, where areas of low 30 to upper 20 percent will be possible. Winds will be generally light.

An arctic trough will descend from the northwest overnight Saturday into Sunday. By Sunday morning, the associated cloud deck and precipitation will span roughly from the Seward Peninsula to the Central Brooks Range to Point Thompson, bringing significantly cooler air in behind it. Temperatures in the Central and Eastern Interior will have a chance to reach around 70F before the cold front arrives later in the afternoon. Winds will become gusty along with the front, westerly ahead of the front in the Interior, but turning more northerly behind the front closer to the West Coast as well as through the Alaska Range. Gusts will blow up to 25 mph for much of northern Alaska on Sunday afternoon. Rainfall amounts associated with this front should be light, generally less than a tenth except on the North Slope where around a quarter and in the Brooks Range where around half an inch is expected.

For the start of next week, a cool air mass will continue to linger over Northern Alaska. Monday will be the coldest day for most areas of the Interior. Max temperatures will likely be 10 to 15 degrees Fahrenheit cooler than normal, peaking in the low 60s or 50s. Conditons should remain moderate, but follow a gradual warming trend through the rest of week, until a ridge provides the chance for temperatures above 70 again for the latter half of the week.

HYDROLOGY

With the recent widespread rainfall, rivers and their tributaries continue to respond and show minor rises as of Saturday morning. The Kuskokwim River at McGrath has shown the highest rise over the past several days, with around a 3.5 foot rise since Wednesday. The Upper Kuskokwim and Alaska Range have seen the highest rainfall totals around 1.5 to 3 inches this week, with most other locations picking up around 0.25 to 1.50 inches. While no flooding is expected, remain mindful of the higher water levels.

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. PK...Small Craft Advisory for PKZ806-810. Small Craft Advisory for PKZ807-856. Small Craft Advisory for PKZ811-857. Small Craft Advisory for PKZ812. Small Craft Advisory for PKZ813-854. Small Craft Advisory for PKZ817. Small Craft Advisory for PKZ858. Brisk Wind Advisory for PKZ859.