What are snow squalls?
Much like rain, snow comes in many different forms and fashions. Falling as scattered flurries or a full blown blockbuster snowstorm, and pretty much everywhere in-between. Snow squalls are a lesser known yet highly impactful form of the white stuff that can quickly create a localized winter wonderland and nightmare for unsuspecting drivers.
The National Weather Service defines a snow squall as “an intense short-lived burst of heavy snowfall that leads to a quick reduction in visibilities and is often accompanied by gusty winds.” These walls of white come in two distinct types, lake effect and frontal.
Lake effect snow squalls occur near large inland bodies of water, most commonly the Great Lakes. As arctic air blows across unfrozen waters moisture can evaporate and condense into an organized band of clouds which generates snowfall.
Frontal snowsqualls occur near and along strong cold fronts, and don’t require bodies of water. As an arctic air mass pushes into relatively warmer air, lift along the frontal boundary can generate bands of moderate to heavy snowfall. These air masses can also be accompanied by a broad trough of low pressure, providing enough lift and instability to generate a scattering of snow squall activity in the hours following a strong cold front.
More intense than a snow shower, but less widespread than a winter storm, snowsqualls can be sneaky and often hyper-local. They also tend to roll in fast, creating rapidly changing conditions for motorists.
Suddenly slick roads and rapidly reduced visibilities that occur in the midst of a snow squall make them notorious for causing high speed collisions and multi-car pileups. Earlier this week a lake effect snow squall in southwest Michigan contributed to a massive 100 car pileup on an area interstate.
Just last week, a series of frontal snow squalls blew through parts of Northwest Missouri and Northeast Kansas, generating patches of snowy roadways and low visibility. During this event, the National Weather Service in Kansas City issued its first ever “Snow Squall Warning” for parts of the KC metro.
A snow squall warning is similar to that of a severe thunderstorm or tornado warning, but instead dealing with bursts of heavy snow. These warnings are a relatively new practice for the NWS as a whole, which began issuing them for parts of the country in 2018 to alert the public of particularly hazardous conditions over specific locations.
