Blizzard Warning Is In Effect For Parts of Montana, But No New Snow Is Expected

Linda Lam
Published: February 13, 2018

When many people think of blizzards, images of heavy snow falling in strong winds comes to mind. Although it may seem odd, blizzard warnings do not actually mean that additional snow will be accumulating.

(MORE: Winter Storm Central)

This is the case in portions of Montana through Tuesday evening. A blizzard warning is in effect for part of northern Montana, including Glacier National Park, where wind gusts up to 65 mph will cause whiteout conditions in blowing snow, likely resulting in blizzard conditions. This is sometimes referred to as a ground blizzard.

In addition, winter weather advisories are also in effect east and south of the blizzard warning, including the Cut Bank, Great Falls and Helena areas. Wind gusts up to 45 mph are expected in the advisory areas, which may cause areas of blowing and drifting snow and consequently poor visibility and slick roadways.

Blizzard warnings are shown in red, while the turquoise indicates winter weather advisories on the morning of Feb. 13, 2018.

So if snow does not have to be falling, what exactly is a blizzard? 

The National Weather Service defines a blizzard when the following conditions are met for at least three hours: sustained winds or frequent gusts to at least 35 mph and considerable falling and/or blowing snow that frequently reduces visibility to less than a quarter-mile. Blowing snow refers to snow that is picked up by strong winds and reduces surface visibility.

(MORE: The Difference Between Blowing Snow and Drifting Snow)

A blizzard warning means that those severe winter conditions mentioned above are likely, making travel extremely dangerous. In areas where a winter weather advisory was issued today in Montana and not a blizzard warning, the visibility requirement may not be met for at least three hours. 

The current setup features Chinook winds in this part of Montana. Chinook winds are the result of a warmer airmass rising over mountain ranges and as the air reaches the ridge tops, it begins to sink and warm as it descends the mountain slopes. The winds that result can be strong and gusty and can also create dramatic temperature changes.

(MORE: Map Shows an Important Factor in How Much Snow You Receive)

There is plenty of snow already in the area where the blizzard warning is in effect, with feet of snow on the ground. Farther east, areas from Cut Bank to Great Falls reported about 6 inches on the ground early Tuesday morning.

Estimated snow depth as of 1 a.m. EST Feb. 13, 2018.

The combination of snow on the ground and the Chinook winds will continue to make for treacherous travel conditions through this evening.

This area of the country is no stranger to blizzard warnings without falling snow. Blowing snow is not that unusual in the northern Plains and mountain West due to the strong winds that can develop here, along with the terrain.

It is important to pay attention to these warnings as conditions can deteriorate here rapidly.

(MORE: Yes, There Is A Blizzard Alley)

These hazardous weather conditions have already resulted in numerous road closures in the area due to the very limited visibility.

Blowing snow was also observed on Monday in central Montana.

Widespread blowing and drifting of snow will end Tuesday night, as the snow will become compacted which will limit the amount of snow available to be blown around. Temperatures will also continue to rise during the day, which will also eventually help to limit the blowing and drifting of snow.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

Featured Blogs

Meteorology of Saturday's Colombian Flood Disaster That Killed 254

By Dr. Jeff Masters
April 3, 2017

At least 254 people were killed in the in the city of Mocoa (population 40,000) in southwest Colombia near the border of Ecuador early Saturday, when torrential rains triggered a debris flow on a nearby mountain that surged into the town as a huge wall of water carrying tons of mud and debris. The disaster is the fourth deadliest weather-related disaster in Colombia’s recorded history.

Iconic American Destination Virtually Isolated for Rest of Year

By Christopher C. Burt
March 24, 2017

Half of the village of Big Sur, on the coast of central California, has lost its only access to the north following the demolition of the flood-damaged Pfeiffer Canyon Bridge along State Route 1 (also Rt. 1 or SR 1) on March 19. Although Rt. 1 to the south of Big Sur has reopened to traffic (after mud and rock slides were cleared) it is a long 70-mile journey along the windy but spectacular highway to Cambria, the next town of any significance where supplies can be had. CalTrans (California Department of Transportation) estimates it will take 6-9 months to rebuild a new bridge over the canyon.

An extraordinary meteorological event; was one of its results a 1000-year flood?

By Stu Ostro
October 5, 2015

The confluence of meteorological ingredients the first weekend in October 2015 resulted in an extraordinary weather event with severe impacts. Was one of them a 1000-year flood?

Why the Arrest of a Science-Loving 14-year-old Matters

By Shaun Tanner
September 16, 2015

By now, many of you have heard or read about the arrest of Ahmed Mohamed, a 14-year-old high school student from Irving, Texas. Ahmed was arrested because school officials called the police after he showed one of his teachers his homemade clock. Mistaken for a bomb, Ahmed was taken into custody, interrogated, shamed, suspended (still on suspension today, Wednesday), and reprimanded. All of this after it has been found that the "device" he brought to school was indeed, a homemade clock.