A "New" Weather Alert This Winter: Snow Squall Warning

A big pileup in Toronto, Canada in 2015 was caused by a snow squall.

Snow flurries dusted much of Vermont yesterday. None were heavy, and none came in the form of the more dangerous heavy snow squall.

But snow squalls are inevitable, and they'll happen this winter. They're basically intense, short-lived localized bursts of very heavy snow.

They are dangerous because they can lead to sudden white outs and suddenly iced over roads on highways. You can go from clear and dry to icy and very blurry in an instant.

Seven National Weather Service offices, including the one here in Vermont, tested a new snow squall warning system last winter, and now everywhere in the nation that can get snow squalls will be subject to snow squall warnings.

The snow squall warnings are much like severe thunderstorm and tornado warnings. They'll usually cover a small area, such as a county or small collection of counties. The warnings will tell you where the snow squall is, where it's heading, which highways it will affect, and what to do about it.

For instance, the National Weather Service office in South Burlington might issue something roughly like this:

"Snow Squall Warning for Chittenden and Franklin Counties. At 1:30 p.m a dangerous snow squall was located along a line extending from Alburgh, Vermont to Plattsburgh and Port Kent, New York, moving east at 40 mph.
Hazard: Heavy snow and blowing snow. Wind gusts to 35 mph. Source: Radar indicated. Impact: Dangerous, life-threatening travel.
This snow squall will be near St. Albans at 1:40 p.m., South Hero by 1:45 p.m and Burlington at around 1:55 p.m. Consider avoiding or delaying travel until the snow squall passes your location. If you must travel, use extra caution and allow extra time. Rapid changes in visibillity and slick road conditions may lead to accidents."

Your weather radio or other weather warning device will go off when a snow squall warning is issued for your area, just like it does when a severe thunderstorm is bearing down on you.

The NWS in Burlington, as I recall, issued one snow squall warning last winter during the experimental phase of this program. I'm sure we'll hear more this winter.

Weather radar has gotten much better at picking up localized hazards like snow squalls. There's better satellite data, improved Doppler radar, and more accurate weather models that help the National Weather Serice detect snow squalls and other hazards.

Snow squalls are a big cause of often fatal and large scale highway crashes. With all these things in mind, the National Weather Service decided snow squall warnings make sense. I wholeheartedly agree.