What is a snow squall?

Snow squalls can cause sudden white-out conditions as well as slick roads

Warnings of snow squall conditions were being issued in the United States on Wednesday as the “historic” Winter Storm Olive tightened its grip.

But what is the lesser-known weather phenomenon?

According to the National Weather Service, a snow squall is an “intense short-lived burst of heavy snowfall that leads to a quick reduction in visibilities and is often accompanied by gusty winds”.

Squalls can be dangerous because they can cause sudden white-out conditions as well as slick roadways, which can make driving or travelling during the weather phenomenon treacherous.

They typically last for between 30 and 60 minutes, during which time the surrounding temperature drops swiftly.

The warnings for snow squalls are similar to those issued for severe thunderstorms or tornadoes, according to the weather service.

When a warning is issued, people in affected areas are instructed to avoid motor travel until it passes. If you’re already on the road, the NWS advises drivers to exit where possible. If there is no opportunity to exit, slow speed, turn on hazard lights, don’t change lanes, increase following distance and avoid slamming on brakes.