At a Glance

National Weather Service offices nationwide will be capable of issuing a new warning.Several NWS offices tested these warnings last winter.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.

The National Weather Service is expanding a new snow warning nationwideto convey the danger travelers face from an extreme reduction in visibility during short-term bursts of heavy snow.BeginningNovember 1, snow squall warnings can be issued by any NWS office when conditions warrant.

The warnings are somewhat similar to tornado, severe thunderstorm or flash flood warnings in that they will only cover a small area, typically only a few counties, and last for anhour or less.

An example of an NWS snow squall warning issued in mid-March 2018. Arrows were added to the polygon to show the direction the snow squall was moving.

Snow squalls have historically been a contributor to major highway pileups due to their brief but intense snowfall rates, dropping 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 for the new snow squall warning.

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Seven NWS offices fromVermonttoWyominghad the capability to issue snow squall warnings last winter as a test before national implementation.

Four of those offices - Binghamton, New York, Burlington, Vermont, Cheyenne, Wyomingand Pittsburgh - issued at least one snow squall warning last winter.

The Federal Emergency Management Agency and wireless carriers are expected to transmitthese snow squall warnings via to your smartphone at a future time.

A snow squall warning issued for your area will trigger the alarm on your.

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For now, you won't see a scroll of a snow squall warning on TV via the Emergency Alert System, but that may change if there is interest from local emergency managers and broadcasters, according to the .

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 showan example of a snow squall in Hollidaysburg, Pennsylvania, on Jan. 12, 2016.

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

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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, allow extra time and turn on your headlights 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:

- : 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)

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

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