What Is A Snow Squall? They Are An Unsuspecting Danger For Drivers

S​now squalls are an unsuspecting danger for travelers, turning driving conditions from good to treacherous in an instant and sometimes resulting in multi-vehicle pileups.

What makes snowfall a "snow squall"? They are brief, but intense burst of snowfall that suddenly drops visibility and can slicken roads. Because of its rapid movement, accumulations from a snow squall are light, but the drop in visibility can create whiteout conditions in minutes.

The National Weather Service (NWS) issues snow squall warnings for the danger. They are of short duration and specify a localized area similar to what you would see with a tornado warning. You can see an example of a warning below that was issued for a snow squall near the border between Pennsylvania and New Jersey on Dec. 3, 2024.

As with all other warnings the NWS issues, they are targeted at state and local officials, media, the general public and others. These warnings will also trigger a Wireless Emergency Alert on your smartphone.

Walking you minute-by-minute through a snow squall encounter. Let's say you're driving in good winter conditions, with the pavement dry. Then, you a white haze some distance ahead. There is no winter storm warning in effect, so you're not concerned about a big snowstorm. You keep driving expecting some snow flurries ahead. No big deal, right?

Within just a few minutes, it all changes. The snow squall arrives.

Strong winds and snow create a whiteout. You can barely see the vehicles in front of you, and a thin film of snow makes the road increasingly slippery.

You hope the vehicles ahead of you don't stop suddenly, or there isn't an accident blocking lanes in front of you, since the sudden drop in visibility and slippery roads can lead to multi-vehicle, chain-reaction accidents.

Scary, right?

Pressing play below or going to this link gives an idea of what it's like to drive into these blinding walls of snow.

They sometimes occur where there is no major large-scale winter storm ongoing. What we mean by this is that they often accompany weather systems that aren't expected to produce snowfall totals high enough to trigger National Weather Service winter weather alerts that cover broad parts of one or more states.

"There are a few rare winter events each year that don't fit the mold of a winter storm warning or winter weather advisory and was determined to be a gap in our services," said Tim Halbach, warning coordination meteorologist at the National Weather Service near Milwaukee in an email to weather.com in 2019.

T​he snow squall warning mentioned earlier was created to fill that gap.

W​hat you should do to stay safe. Next time you hear "snow squall" mentioned by a meteorologist in your area, take the threat seriously.

-Delay your trip until the snow squall passes. Put simply, there is no safe place on the road in a snow squall.

-If you must travel, turn on your headlights, slow down, leave more distance between you and the vehicle in front of you and avoid slamming on your brakes, which could lead to a loss of control on a slippery road.

-If you become stopped on the road or involved in an accident, only if it is safe to do so, exit your vehicle and move as far away from the road as possible. Do not stand along or near the road, as approaching vehicles may not be able to see you and may have lost control of their vehicles.

Chris Dolce has been a senior meteorologist with weather.com for over 10 years after beginning his career with The Weather Channel in the early 2000s.