What is a snow squall? Warning issued in Chicago area as white-out conditions snarl morning commute
Chicago weather Wednesday morning took a sudden turn for the worst, and a Snow Squall Warning was issued. But what is a snow squall?
A snow squall is an intense short-lived burst of heavy snowfall associated with gusty winds that leads to a quick reduction in visibilities and is often accompanied by gusty winds. They may be characterized by one main squall or multiple squalls.
According to the National Weather Service, they are often associated with strong cold fronts but they can happen at any time. As a result, flash freezes can happen with the dropping temperatures paired with the wet ground.
Snow squalls are strong winter weather events, creating sudden white-out conditions that, combined with dropping temperatures, can ice over roads in a matter of minutes.
Squalls often occur outside of large-scale winter storms, according to the NWS, and don't' usually produce major accumulations. But they are distinct hazards for drivers and commuters, and the NWS says there's "a long history of deadly traffic accidents associated with snow squalls."
The primary difference between a snow squall and a snow storm is the duration; snow squalls are quick, lasting 30 to 60 minutes, while winter storms last much longer – several hours or even days.
As a result, Snow Squall Warnings are more akin to tornado and severe thunderstorm warnings than other types of severe weather alerts: short in duration, severe in scope.
When a Snow Squall Warning is in effect, it's best to delay driving if at all possible until the squall has passed, and crews can treat the roads. This is especially crucial on highways; the NWS warns there is "no safe place on the highway during a snow squall." If you're already on the road and can't exit, reduce your speed, turn on your headlines and hazard lights, and allow as much distance between you and the car in front of you as possible.
If you can, try not to slam on your brakes, too. If it's possible to pull over, you should.
Roads treated with salt and other anti-ice measures will be safe for travel, but any untreated areas will be slick.