Arctic blast heads east

Arctic blast heads east
Temperatures this morning close to -50° F in parts of Yukon Territory

The potent winter storm moving out of the Northwest tonight will spread a nasty mix of wintry weather across the northern Plains. Ahead of the low pressure, the clash of mild and cold air will lead to icy conditions, while behind the low there will be heavy wind-whipped snow and bitterly cold temperatures.

Today, the storm dumped more snow in the mountains of Washington and Oregon before moving over the northern and central Rockies. According to the Severe Weather Center, the storm-related watches and warnings will expire by tonight, but not before the storm dumps more than a foot of snow across the Intermountain West and the Sierras in Northern California.

Gusty winds topping 40 mph have led to blowing and drifting snow, significantly reduced visibility and dangerous winter driving conditions. Earlier today, Interstate 90, the main east-west corridor in Washington State, was closed over Snoqualmie Pass while crews conducted avalanche control work.

The Winter Weather Center has additional information on this major winter storm.

The storm will move across the northern Plains tonight and through Tuesday. The collision of the cold advancing air and the milder air already in place and the addition of sub-freezing surface temperatures will lead to icy conditions from the eastern Dakotas to the Great Lakes, while snow and gusty winds in excess of 40 mph will blanket Montana and North Dakota.

Winter Storm Watches are in effect through Tuesday from eastern Montana across virtually all of North Dakota and into western Minnesota. Again on Tuesday, lowing and drifting snow will create reduced visibility and treacherous driving conditions. South of the cold front, where temperatures will be above freezing, there will be a broad swath of rainy weather across the Midwest.

A second area of low pressure developing today will bring snow on Tuesday and Wednesday to the Front Range of the Rockies as far south as New Mexico. One to three inches of snow is forecast in Denver, Colo. from Tuesday night into Wednesday, with up to two feet possible at many of Colorado's ski resorts. Snow showers could develop as far south as Albuquerque, N.M., with heavier snowfall amounts forecast across the higher terrain of northern and central New Mexico.

Arctic Blast Follows the Snow and Rain

Arctic air that had been bottled up across Alaska and Canada's Yukon Territory pressed into Washington and Oregon on Sunday, and will continue to grip the Northwest through Wednesday before following the storm system to the east.

Temperatures across the Northwest will recover slightly on Thursday as the core of the arctic air shifts into the Plains; however, another system, though not as chilly, will deliver more rain and snow to the region.

The advancing cold air mass will bring dramatic changes in temperatures later in the week across the Upper Plains, the Midwest and the Northeast.

Second Storm will Spark Rain and Snow Later in the Week

While the potent winter storm moves across the northern Plains over the next couple of days, another storm system will be developing along the Gulf Coast. The second storm will move northeast out of Texas on Wednesday, sparking rain and thunderstorms to the south of the front and snow behind the storm. Amarillo, Tex., and Guymon, Okla., could receive as much as three inches of snow before the storm moves into the Ohio Valley late on Thursday into Friday. The remainder of the southern Plains will be lashed by strong winds that will result in RealFeel® temperatures that will feel much colder than the actual temperatures.

East Gets Chilled Before the Real Cold Arrives

As the bitterly cold arctic air begins its march across the country most of the East will enjoy another warm day on Tuesday. However, a "back door" cold front that will drop out of Atlantic Canada will bring a noticeable change in conditions across much of New England.

Highs today surged into the 60s as far north as southern New York challenging a number of records. The mild temperatures will continue on Tuesday from the Ohio and Tennessee valleys into the Mid-Atlantic. Meanwhile, the front will bring a few showers and much cooler temperatures to New England. The high Tuesday in Boston will struggle to reach 50, while temperatures in the 40s will be the norm in Maine.