textproduct: Fairbanks

KEY MESSAGES

Central and Eastern Interior... - Colder/drier weather for most of the Interior through Monday.

- Snow moves into the Alaska Range Monday afternoon and persists through Wednesday. Very heavy snow with rates exceeding 1 inch per hour at times Monday night through Tuesday night. * Snowfall totals upwards of 2 to 3 feet in Isabel Pass.

- Snow, heavy at times moves into the Interior Monday night and persists through Wednesday. A tight snow gradient sets up from east to west around Fairbanks. Gusty north/northwest winds likely, especially in the AK Range and Eastern Interior Tuesday afternoon with visibility restrictions possible. * Snowfall totals around 4 to 8 inches around Fairbanks. * 5 to 10 inches from Harding Lake to Eagle Summit. * 6 to 12 inches for most of the Eastern Interior with locally 12 to 18 inches between Tanana Cross & Dot Lake. 2 to 5 inches near Northway.

- Most of the snow dissipates by Wednesday afternoon with cold and dry weather settling in Thursday/Friday. Temperatures may drop to the single digits/teens Wednesday night and near 0 Thursday night across much of the Interior.

West Coast and Western Interior... - Rain and snow showers persist through tonight with a period of snow likely in Southwest Alaska this evening through Monday afternoon then tapering off. * Snowfall totals around 1 to 3 inches with locally higher amounts in the Lower Yukon Valley. * Rain will mix with snow at times along the YK Delta Coast. But during periods of snow and gusty wind, visibility restrictions are expected.

- Moderate snow is likely to continue around Kivalina, Red Dog Mine and Point Hope. Winds will gust as high as 40 mph making for poor visibility. * Snow accumulations around 3 to 6 inches through Monday.

- Temps will range with highs in the 20s/30s for both the West Coast and Western Interior. The lows along the West Coast will likely range in the lower 20s, while the Interior will remain slightly cooler, with lows in upper teens.

- A strong coastal storm is becoming more likely as early as Thursday. For more details, see the coastal hazard and long range forecast sections.

North slope and Brooks Range... - Snow likely in Point Lay and Point Hope through this evening. * 1 to 3 inches of snow expected.

- Gusty winds up to 40 mph expected along the Chukchi Sea Coast with 20 to 30 mph along the Beaufort Sea Coast today. It remains breezy but weaker tomorrow.

- It remains below freezing for most of the North Slope, except the Chukchi Sea Coast which remains near/above freezing.

SYNOPSIS

Active weather continues in Northern Alaska with snow from Point Lay to Kivalina/Red Dog, heaviest in the Red Dog Mine where several inches of snow are likely through Monday. Winds will be gusting upwards of 40 mph in these locations making for minor blowing snow. Another spot we are monitoring for snow is Southwest Alaska, especially in the Lower Yukon Valley where light snow will increase in intensity this evening, then continue through Monday afternoon. Monday to Wednesday will come with heavy snow in the Interior, especially the Eastern Alaska Range and Eastern Interior. The heaviest will be in Isabel Pass where we might be measuring snow in feet. Otherwise the Central Interior, such as Fairbanks, will be right in the zone of the most uncertainty where a 30 mile shift west or east will result in significant amounts or close to nothing. There will be an in depth analysis in the short term discussion.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

A lot to get into so we'll start with 500mb vorticity charts. The broad view shows troughing from the Arctic to the Bering with a subtle, transient ridge over the Interior. This is allowing for breaks in the clouds in the Interior. A picturesque Arctic low at 497 decameters northwest of Utqiagvik and a shortwave trough moving north over Western AK is helping force a narrow band of snow from the Chukchi Sea to the NW Arctic Coast. A broad, weak, 524 decameter upper low is sitting south of the Gulf of Anadyr and this is helping provide rain/snow showers to the West Coast. To the southwest of this low is a potent piece of vorticity which will be moving towards SW AK this afternoon/evening allowing for snow to blossom in the Yukon Valley and along the West Coast from Unalakleet south. Snow will continue through Monday afternoon before dissipating. This piece of energy will continue trekking northeast bringing light snow showers to much of the Interior, especially north and west of Fairbanks on Monday night into Tuesday. If you're wondering why the Tanana Valley/Eastern Interior might not see snow, it is due to strong downsloping. The Alaska Range will have southerly winds gusting around 55 to 65 mph, strongest in Isabel Pass. Meanwhile, the Arctic low will be lifting to the northeast with a cold front dragging southeast, slowly moving through the North Slope and Western Interior on Tuesday. This will play an important role moving forward.

Before we get there, a strong piece of energy will move into the Gulf of Alaska on Tuesday and nearly undergo bombogenesis (strengthening >24mb in <24 hours) before forcing itself into Prince William Sound and the Interior Tuesday afternoon into Wednesday. From here, the models do diverge a little bit. Some take the energy farther east over The Yukon, while others move it over the AlCan. These differences are very important in determining where the heaviest snow sets up. 700mb dynamics are indicating there will be a tremendous amount of lift, both with frontogenesis and vorticity advection. This is especially true in the Eastern Interior and Eastern AK Range. Highest confidence for heavy snow greater than 6 inches exists in the Eastern Interior, specifically the Upper Tanana Valley, west of Northway, Fortymile Country and Isabel Pass. Isabel Pass likely begins snowing as early as Monday and continue through Wednesday with snowfall rates exceeding 1 inch per hour at times from Monday night through Tuesday night. There is a potential for feet of snow around Trims Camp. The tricky spot is directly over Fairbanks. As the cold front moves in from the northwest, it will be providing colder and drier air. The low moving northeast from the Gulf will bring warm, moist air. There will be a boundary directly over FNSB where these two features meet. One thing to note is, 700mb vorticity shows a deformation zone setting up and pivoting from Circle to Isabel Pass (and continuing southwest). This deformation zone would tend to lean towards moderate to heavy snow somewhere near FNSB. Based on current trends, the greatest likelihood for this to set up is from Eielson to Chena Hot Springs to Circle. Fairbanks may only end up with light snow accumulations with nearly nothing in Minto and Tanana. It will be a very tight gradient from significant snow to no snow at all and a 30 mile shift west or east will make exceptional differences in the Fairbanks area. To give another reference on how narrow this is, some guidance indicates 6 to 8 inches in Eielson with 2 inches in Fairbanks. It will be difficult to pinpoint the exact location until more mesoscale models become available.

After this storm moves through it will get quite cold in the Interior, especially Thursday and Friday mornings where temperatures may approach or go below zero in some spots. At this time, there will be a low approaching the Bering Sea which may bring significant impacts to the West Coast. A more in depth look is in the long term forecast below.

LONG TERM /THURSDAY THROUGH SUNDAY/

On Thursday we should see a brief pause between active weather as an upper-level ridge moves over Alaska. This ridge will cause temperatures in parts of the Interior to dip into the single digits Thursday into Friday as 850 temperatures over the Interior fall to 10 to 15C below zero and skies clear.

Models are in good agreement on having this ridge stall and build over eastern Alaska on Friday. This will also put the brakes on a low arriving in the Bering behind the ridge. The strengthening of the ridge along with the relatively high strength of low will work together to produce an impressive pressure gradient between the two features. As a result, strong south/southwest winds develop from the Pacific toward the West Coast, resulting in coastal concerns for the southern West Coast. This will carry a significant amount of moisture toward Western Alaska. The bulk of the initial precipitation on Friday is expected to be wet snow, hitting the southern Seward Peninsula and southern Brooks Range. When paired with the strong winds, blizzard conditions may be possible. The band of snow will advance farther inland on Saturday, but as warmer, southerly air comes in behind the front, snow will change to rain along the Coast. It remains uncertain how far into the Interior precipitation will make it. It will depend heavily on the strength and orientation of the ridge and the resulting trajectory of the Bering low. The low may be deflected north, in which case precipitation remains mostly in Western Alaska. Otherwise, it may take a more easterly track pushing a band of rain and snow into the Interior. Winds through the Alaska Range passes are expected to peak Saturday, likely at hazardous levels given the strong gradient as the low pushes against the ridge.

After the first Bering Sea low exits, another low looks to take its place late Sunday potentially extending the duration of southwest winds into Norton Sound and presenting further coastal concerns.

Coastal Hazard Potential... A strong Bering Sea low develops and moves east of the Kamchatka Peninsula on Thursday. This low will bring a front with southerly wind gusts potentially over 60 mph to the West Coast Thursday night into Friday morning. After this, a long fetch of persistent, southwest flow is expected along most of the West Coast, especially from the Seward Peninsula southward Friday into Saturday. This will result in high water and potential coastal flooding. North of the Seward Peninsula, from Kivalina to Point Lay, the overall wind direction looks to be south/southeast. At this point it is too early to give exact values but significant coastal flooding is not entirely ruled out next weekend.

AFG WATCHES/WARNINGS/ADVISORIES

AK...Winter Storm Warning until 4 PM AKDT Monday for AKZ814. Winter Storm Warning from 10 AM Tuesday to 4 PM AKDT Wednesday for AKZ833-834-838. Winter Storm Warning from 10 PM Monday to 4 PM AKDT Wednesday for AKZ835>837. Winter Storm Watch from Tuesday morning through Wednesday afternoon for AKZ839>845. Winter Storm Watch from Monday afternoon through Wednesday afternoon for AKZ847-848. Wind Advisory from midnight tonight to 10 PM AKDT Monday for AKZ849. Winter Storm Warning from 7 AM Monday to 4 AM AKDT Thursday for AKZ849-850. MARINE...Small Craft Advisory until 10 PM AKDT this evening for PKZ801- 806-858. Small Craft Advisory until 4 PM AKDT this afternoon for PKZ802- 805-811-853-857. Small Craft Advisory from 4 PM to 6 PM AKDT Monday for PKZ806- 807-854. Small Craft Advisory until 7 PM AKDT this evening for PKZ810- 812-850. Small Craft Advisory until 1 AM AKDT Monday for PKZ813-859. Brisk Wind Advisory until 10 PM AKDT this evening for PKZ858. Brisk Wind Advisory until 1 AM AKDT Monday for PKZ859.