textproduct: Fairbanks

SYNOPSIS

Active weather continues for the North Slope, West Coast, the Brooks Range and the Northern Interior due to either periods of snow, gusty winds and blowing snow, as well as blizzard to near blizzard conditions along the Arctic Coast from Point Hope to Kaktovik. For the above reasons, Blizzard Warnings and Winter Weather Advisories remain in effect for the Arctic Coast through at least Wednesday with potential to extend some of these through Friday. Gusty winds and snow chances continue in the Northern Interior through mid-week, especially for the higher elevations. Blowing snow and gusty winds become of greater concern Tuesday through Wednesday night around the Dalton, Elliot and Steese Highway Summits which resulted in the issuance of a Winter Storm Watch. Otherwise, generally dry and quiet conditions persist with temperatures trending warmer by mid-week in the Interior, although Delta Junction and the Middle Tanana Valley are expected to get more gusty winds midweek. Cold temperatures persists for the North Slope for the foreseeable future.

KEY WEATHER MESSAGES

Central and Eastern Interior...

- Generally quiet and dry conditions with a mix of sun and clouds and strong inversions persist over the next few days.

- Temperatures for the coldest valleys will reach down to around -10F to -20F through Tuesday morning.

- Isolated light snow showers will continue across the Northern Interior through Monday night, with increasing snow chances building in from the southeast Tuesday into Wednesday. Accumulations between a T-3" are expected with the highest amounts in the mountains.

- A Winter Storm Watch has been issued for the Dalton, Elliott, and Steese Highway Summits from Tuesday through Wednesday night for gusty winds and blowing snow.

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

West Coast and Western Interior...

- Light snow showers will continue across the West Coast and Northwest Interior through tonight, with additional snow accumulations around a T-1".

- Northeast winds will continue to increase across Western Alaska tonight into Monday and Tuesday, with strongest winds expected along the West Coast and across higher elevations. Gusty winds may lead to areas of blowing snow at times through mid-week.

- Temperatures hold steady today with highs from the single digits to the teens, and lows in the single digits above and below zero with the coldest locations dropping to around -15F. A dip on temperatures is expected on Tuesday, before a warm trends sets by midweek 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...

- An 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 in effect through Wednesday. These could potentially be expanded later in the week.

- Light snow showers will continue through Monday, favoring the Brooks Range and Eastern North Slope. Additional snow accumulations of a T-2" are expected.

- Temperatures cool down to the -10F to -30F range this week with even colder wind chills down to -40 to -50F.

FORECAST ANALYSIS AND DISCUSSION

Today through Wednesday Night.

Active weather continues across the area as observations in the West Coast, Northern Interior, the Brooks Range and the Arctic Coast continue to indicate periods of light snow. Furthermore, gusty to strong northeast winds persist along the coastal and high elevation areas. Blizzard to near blizzard conditions remain in the warned areas along the Arctic coast this morning. Point Hope and Cape Lisburne have had periods of near blizzard conditions overnight. Blowing snow and reduced visibility persists between Wainwright and Kaktovik. Therefore, no changes to the current Blizzard Warning and Winter Weather Advisory is expected.

The advertised weather pattern over the weekend appears to come to fruition this week. A high amplitude upper level ridge extends all the way from the US West Coast through Central Alaska, while another upper high sits in the Arctic Ocean. Meanwhile, near the surface a 1040mb high in the Arctic interacts with a surface low in the Gulf of Alaska tightening the pressure gradient across the state, especially from the Bering Strait to the Arctic Coast. As the surface high expands to the east and the low tracks towards southwest Alaska; this will aid in enhancing strong and gusty winds in the West Coast and Arctic Coast, especially between Point Hope to Point Lay, where gusts of 50 to 65 mph are likely to continue through Wednesday. Current ensemble guidance from the GFS and ECMWF continues to indicate that these winds are expected to continue through most of the week with a very slow decrease in winds during the second part of the week. For the rest of the Arctic Coast, from Wainwright to Kaktovik wind gusts of 30 to 40 mph persist with an increase in winds on Tuesday into Wednesday to 40 to 50 mph. Although this is less likely, as most members of the ensembles are keeping the winds up to 40 mph with the latest run. Still periods of blowing snow and reductions in visibility will continue until the gradient relaxes during the second half of the week.

Another area of concern will be the Northern Interior between Tuesday and Thursday as moisture is advected north from a shortwave ejected from the low in the Gulf of Alaska. Periods of snow are expected across the Interior, especially for the summits of the Dalton, Elliott and Steese Highways and other high elevations areas, where 1 to 3 inches of snow are likely with a 40-80% chance of exceeding 2 inches. The rest of the area will receive a trace to 1 inch of snow. Gusty to strong east to northeast winds in the Northern Interior will result in periods of blowing snow and reduced visibility, as gusts to 55 mph are possible. The latest model runs have brought this system slightly earlier. Thus, decided to start the Winter Weather Watch earlier, now starting at 9 AM Tuesday to encompass the period of the strongest winds and the best chances for snow.

Also, southerly gap winds develop on Tuesday night into Wednesday morning leading to gusty winds around Delta Junction and the Middle Tanana Valley.

EXTENDED FORECAST DAYS 4-7

Thursday through next Sunday Night.

In the extended part of the forecast, the main area of concern is the placement of the Arctic and how fast it will move west; to allow the pressure gradient to relax resulting in lighter winds over the Arctic Coast. At the moment, the latest ensemble and deterministic guidance continues to show a slow westerly trajectory, which will lead to gusty winds persisting in the Western Arctic Coast. However, the ensembles of the ECMWF keep gusts in the 40 to 50 mph range, while the ensembles of the GFS have a lot more variability with a drop from Thursday and through the weekend into the 30 to 40 mph range. So, there are two scenarios, but both of them would still keep periods of blizzard to near blizzard conditions. Therefore, the likelihood of the Blizzard Warning to be extended through the rest of the work week. Meanwhile, from the Northwest to the Northeast Arctic Coast guidance shows a quick drop of winds Thursday and beyond.

For this weekend, a deep upper level trough in far north Nunavut expands towards the North Slope and Brooks Range bringing back colder temperatures down to -20 to -30F with wind chills remaining in the -40 to -50F. Farther, south into the Interior the weakening of the upper ridge will decide if we get an upper trough moving towards the Eastern/Central Interior, or will it take a more northerly track into the Bering Strait and the West Coast. We will have to wait and see where the solutions of the next model runs end up to gain more confidence in the forecast for this weekend.

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

AFG WATCHES/WARNINGS/ADVISORIES

AK...Blizzard Warning for AKZ801. Winter Weather Advisory for AKZ802>805. Winter Storm Watch for AKZ832-834. PK...Brisk Wind Advisory for PKZ801>803. Brisk Wind Advisory for PKZ804. Brisk Wind Advisory for PKZ805. Brisk Wind Advisory for PKZ806-807-809-813-814-816-817-851-854- 859. Gale Warning for PKZ810. Gale Warning for PKZ811-812-856>858. Brisk Wind Advisory for PKZ815. Brisk Wind Advisory for PKZ850. Brisk Wind Advisory for PKZ852. Brisk Wind Advisory for PKZ860. Brisk Wind Advisory for PKZ861.