Winter Storm

New Type of Snow Warning Can Now Be Issued by the National Weather Service

At a Glance

Several National Weather Service offices can now issue snow squall warnings.
Snow squalls contain brief but intense snowfall rates that drop visibility and slicken roads.
The sudden change to poor weather conditions can lead to dangerous travel conditions.

A new type of snow warning can now be issued by the National Weather Service (NWS) to convey the danger travelers face from an extreme reduction in visibility during short-term bursts of heavy snow.

The new winter weather alert is called a snow squall warning, and as of Jan. 16, 2018, it can be issued by NWS offices in Detroit, Pittsburgh, State College, Pennsylvania, Binghamton, New York, and Burlington, Vermont. The warnings are posted when conditions warrant in the local forecast area for each of those offices.

Two additional NWS offices will also eventually issue these new warnings. Cheyenne, Wyoming, is expected to implement the snow squall warning on or about Jan. 31. Buffalo, New York, will follow at a later date.

(MORE: Winter Storm Central)

In general, these snow squall warnings will be of short duration and specify a localized area similar to what you would see with a tornado, severe thunderstorm or flash flooding warning.

As with all other warnings the NWS issues, they are targeted at state and local officials, media, the general public and others.

To the right is an example of the information contained in a snow squall warning, including cities and highways affected and how long it will last.

Snow squalls have historically been a contributor to major highway pileups due to their brief but intense snowfall rates, which drop visibility quickly while slickening roads. Snow squalls can occur in situations where there is no major large-scale winter storm in progress and may only produce minor accumulations.

"Annual highway fatalities from these events can exceed fatalities due to tornadoes in many years," the NWS said in its product description for the new snow squall warning.

Time series every 6-8 min from 2:59 pm to 3:20 pm of a snow squall in Hollidaysburg, Pennsylvania, Jan. 12, 2016. Credit: wunderground.com

The series of images above show an example of a snow squall in Hollidaysburg, Pennsylvania, on Jan. 12, 2016.

Notice how the visibility in the top two images of the series went from good to poor in about eight minutes. At the bottom right, you can see the visibility improve after the snow squall had ended about 13 minutes later.

(MORE: Weather-Related Car Accidents Far More Deadly Than Tornadoes, Hurricanes, Floods)

If a snow squall warning is issued for your area, the NWS has this advice:

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 visibility and slick road conditions may lead to accidents.