LOLO, Mont. — Snow is certainly nothing new for Montana, and we all are well aware that driving in a snowstorm can be difficult. Add blowing wind and heavily reduced visibility to the mix, and conditions can become downright dangerous.
Through the winter, western Montana could experience blizzards and snow squalls. What criteria make these two winter storms different? Meteorologist Mitchel Coombs explains in the video above.
3D Weather: Defining snow squalls and blizzards
Blizzards are defined by the National Weather Service when there is blowing and/or falling snow with winds of at least 35 mph, reducing visibility to a quarter of a mile or less for at least three hours. We can still see blizzard conditions even if it is not snowing outside but the wind is blowing snow around reducing visibility. This is known as a ground blizzard.
Definition of a blizzard by the National Weather Service
Snow squalls, on the other hand, are fast-moving narrow lines of heavy snow and strong wind. From clear conditions to a sudden onset of intense bursts of snow and wind. You could even experience whiteout conditions with rapidly deteriorating road conditions. These events often have a flash freeze component on impacted roads. They are typically short-duration events, lasting only about 30-60 minutes.
The first known use of the term “snow squall” was back in 1775.
The first use of “snow squall” was in 1775
However, it was not until 2018 that the National Weather Service designated the use of a Snow Squall Warning to address these short-term life-threatening conditions. These warnings are more akin to a Severe Thunderstorm or Tornado Warning.
Snow Squall Warnings first implemented in 2018
Whether you are under a Blizzard Warning or a Snow Squall Warning, both are dangerous to travel in as they can lead to high-speed accidents and large pileups. Travel is highly discouraged during both of these winter storms, so stay off the roads if a warning has been issued. If you are already driving when the warning is issued, put on your hazard lights and find a spot to pull off the road.
Keep in mind, it takes much longer to stop a vehicle on snowy and icy roads. You may suddenly be driving toward a pileup and can’t stop in time. Using this example, a car travelling at 40mph will stop on a dry road in about 80 feet. Double that distance for a snowy road and increase it by nearly 5 times the distance for snow & ice.
Stopping distances in snowy and icy road conditions
We are likely to experience more snow squalls and potential blizzards during the winter season, so be prepared for rapidly changing weather and travel conditions as you hit the road. Download the NBC Montana Weather App to be notified of Blizzard and Snow Squall Warnings in your area.
