textproduct: Fairbanks

SYNOPSIS

In general, fair and dry weather continues across the majority of northern Alaska. However, light snow chances and gusty to strong winds are expected to continue over portions of the West Coast, North Slope and Brooks Range through Monday. A long period of blizzard conditions are expected across the Western Arctic Coast from Point Hope to Point Lay, as well as blowing snow and localized blizzard conditions for the rest of the Arctic Coast through the Canada border. Therefore, Blizzard Warnings and Winter Weather Advisories are in effect for those areas through at least Wednesday with a likely upgrade of the advisories to a blizzard warning around mid-week due to stronger winds. Gusty winds are also likely over portions of the Central Interior near the Dalton and Elliot Highways early this week along with periods of light snow that could cause travel difficulties. Enhanced southerly winds over the Interior will lead to warmer temperatures this week, but northeasterly winds north of the Brooks Range lead to colder wind chills.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Generally quiet and dry conditions along with strong inversions continue through the next several days.

- Temperatures for the coldest valleys will reach down to -10F to -25F with warmest higher elevations reaching up to the 20s/30s through Tuesday.

- Isolated light snow is expected today and tomorrow over the Interior, with better snow chances building from the southeast late Tuesday into Wednesday with the best chances across the higher elevations.

- Temperatures rise mid to late week as winds ramp up across the higher elevations and the Middle Tanana Valley.

West Coast and Western Interior...

- Light snow showers continue across the West Coast and Northwest Interior through Monday night with additional snow accumulations of a T-2 inches.

- Wind gusts up to 40 mph continue from the Bering Straight south to the Y-K Delta and in the Interior Norton Sound through tonight.

- Winds will steadily increase from the NW Arctic Coast southwest to St. Lawrence Island today into Monday. Wind gusts up to 45 mph in this corridor may lead to areas of blowing snow at times.

- Temperatures hold steady through tomorrow with highs in the single digits and teens and lows in the single digits above and below zero with coldest locations dropping to around -15F. A dip on temperatures is expected on Tuesday before a warm trends sets by mid-week with highs into the 10s/20s above zero.

- Light snow chances will increase across Western Alaska Wednesday into Thursday, but with light accumulations expected.

North Slope and Brooks Range...

- Light snow showers will continue through Monday, favoring the Brooks Range and the Eastern North Slope. Additional snow accumulations of a T-3" are expected.

- Another extended period of blowing snow and low visibility is expected through at least mid-week across the Arctic Coast, with a mix of Blizzard Warnings and Winter Weather Advisories now in effect Sunday through Wednesday. These could be potentially expanded through Thursday or Friday.

- Temperatures cool down to the -10F to -30F range heading into early next week with even colder wind chills down to -50F. This will be followed by a gradual warming trend for the second half of the week.

FORECAST ANALYSIS AND DISCUSSION

Today through Tuesday Night.

An upper ridge dominates the weather in Central Alaska at this time as mostly clear skies are observed in nighttime microphysics satellite imagery. These conditions are allowing for strong inversions to persist in the Interior as light winds, clear skies and dry conditions prevail. In the periphery of the ridge, we have low clouds and light snow showers, mainly along the West and Arctic Coasts. A weak shortwave moving north over the Y-K Delta is enhancing the dynamics to develop light snow in the region. That's not the only low pressure system in the region as a conglomerate of shortwaves are rotating around a 985mb low pressure in the Gulf of Alaska. The interaction of this low with the Arctic high pressure system is enhancing the pressure gradient, especially in areas near the Chukchi Sea and the Western Arctic Coast. Thus, gusty winds are increasing this morning with gusts of 40-50 mph as of the time of this writing. Gusts from the northeast are expected to reach up to 65 mph which is the reason for the Blizzard Warning. Blowing snow due to gusty winds is also expected across much of the Arctic Coast later today as the high slowly moves east, but at least winds are not expected to be as strong early this week with max gusts up to 30-40 mph. However, these conditions are expected to deteriorate once the Arctic high centers north of Alaska and the low in the Gulf of Alaska strengthens to a 955 mb low which is quite strong. So, the current Winter Weather Advisory may need to be upgraded to a Blizzard Warning as with stronger winds the localized blizzard conditions may become widespread.

The low over the Gulf will eject shortwaves towards the Alaska Range by Tuesday. These waves will push moisture towards the Interior resulting in periods of snow on Tuesday into Wednesday. However, snow amounts are expected to be light in the Central Interior. The snow will favor the higher elevations of the Eastern Interior and into Canada. However, the best snow accumulations will be in the Yukon. There is around a 10-40% chance of snow accumulations greater than 2 inches for the higher elevations of the Eastern Interior, and up to 60% for the Western Alaska Range by Wednesday morning. The passes may have a trace up to an inch of snow. The other concern for the Alaska Range and passes will be gusty winds on Tuesday night as winds shift to the south strengthening gap winds in the region. These winds may lead to blowing snow in the passes, as the winds start just after the snow has fallen. Winds will also start to increase from the east and northeast in the northern portions of the Central Interior on Tuesday night with gusts in the 25-40 mph range.

Temperatures also drop in the Brooks Range and North Slope as the northerly winds push a colder airmass into the region. Temperatures early this week will continue to cool down to the -10 to -25F by Tuesday with wind chills down to -40 to -50F below zero. In the Interior, the strong inversions will continue to support temperatures dropping into the -10 to -30F in the coldest valleys. However, the increase in winds towards mid-week will help start breaking those inversions by Tuesday night, especially in valleys closer to the Alaska Range.

EXTENDED FORECAST DAYS 4-7

Wednesday through next Saturday Night.

The active weather pattern continues by mid-week. The blizzard conditions persist in the Arctic Coast as the high slowly retreats from the region. ECMWF ensemble guidance continues to indicate strong wind gusts for Point Hope and vicinity through Saturday with a break of sorts on Thursday. However, winds would still be quite strong. For the rest of the Arctic Coast, the strongest winds are still expected between Wednesday and Thursday with a quick drop late on Thursday. As the center of the high retreats to the east and the winds take more of a southerly orientation temperatures will gradually increase over the North Slope, but remain quite cold.

The northern portions of the Eastern and Central Interior appear to become quite active with respect to winds as those continue to increase on Wednesday and Wednesday night. The main areas of concern will be near the summits of the Dalton and Elliot Highways, where gusty winds are possible with a 40-80% chance of receiving gusts greater than 35 mph from the east and northeast. These could lead to areas of blowing snow and visibility reductions.

Coastal Hazard Potential Days 3 and 4...None.

AFG WATCHES/WARNINGS/ADVISORIES

AK...Blizzard Warning for AKZ801. Winter Weather Advisory for AKZ802>805. PK...Brisk Wind Advisory for PKZ804-815>817. Brisk Wind Advisory for PKZ805. Brisk Wind Advisory for PKZ806-807-814-861. Brisk Wind Advisory for PKZ809-850. Brisk Wind Advisory for PKZ810-813-859. Gale Warning for PKZ811. Gale Warning for PKZ812-858. Brisk Wind Advisory for PKZ851. Brisk Wind Advisory for PKZ854-860. Gale Warning for PKZ856. Gale Warning for PKZ857.