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

Chris Dolce
Published: January 31, 2018

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.

Example of a snow squall warning.

(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.

Past History Shows Snow Squalls Are a Major Highway Danger

Major highway pileups caused by snow squalls occur every winter.

Here are a few recent examples:

- March 3, 2017: A 30-vehicle pileup on Interstate 81 in Schuylkill County, Pennsylvania, killed one person and left several others injured.

Vehicles pile up at the site of a fatal crash near Fredericksburg, Pennsylvania on Feb. 13, 2016. The pileup left tractor-trailers, box trucks and cars tangled together across several lanes of traffic and into the snow-covered median. (James Robinson/PennLive.com via AP)

- March 4, 2016: Snow squalls caused a 40-car pileup on Interstate 93 in New Hampshire that left ten people hospitalized.

- Feb. 13, 2016: A burst of heavy snow led to a pileup of 50 cars on Interstate 78 in Lebanon County, Pennsylvania, that killed three people.


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