Skip to content
DAMWeather DAMWeather DAMWeather

The weather can get scary. Reporting on it doesn't have to be.

DAMWeather DAMWeather DAMWeather

The weather can get scary. Reporting on it doesn't have to be.

  • About Me
  • All Bylines
    • Books, Bylines, and Press
    • The Skies Above (Book)
    • Extreme Weather (Book)
    • The Weather Network
    • The Vane
    • Forbes
    • Capital Weather Gang
    • Mental Floss
  • Maps
    • Hurricane Maps
    • Hurricane Names
    • Monthly Tornadoes
    • Tornado Tracks
    • F5/EF-5 Tornadoes
    • SPC High Risk Days
  • GIS Resources
  • Contact Me
    • Bluesky
    • Facebook
    • Instagram
  • wxdam.com
  • About Me
  • All Bylines
    • Books, Bylines, and Press
    • The Skies Above (Book)
    • Extreme Weather (Book)
    • The Weather Network
    • The Vane
    • Forbes
    • Capital Weather Gang
    • Mental Floss
  • Maps
    • Hurricane Maps
    • Hurricane Names
    • Monthly Tornadoes
    • Tornado Tracks
    • F5/EF-5 Tornadoes
    • SPC High Risk Days
  • GIS Resources
  • Contact Me
    • Bluesky
    • Facebook
    • Instagram
  • wxdam.com
Close

Search

Those New ‘Snow Squall Warnings’ Are Designed To Prevent Deadly Pileup Accidents

By Dennis Mersereau
December 19, 2019 3 Min Read

Millions of smartphones across the Northeast flashed an unfamiliar warning on Wednesday afternoon. The message came across as a push alert with the iconic screeching tone and an abrupt vibration: “Emergency Alert. Snow squall warning until 4:15 PM. Sudden whiteouts. Icy roads. Slow down! -NWS” These alerts may seem a little excessive on first glance, but they’re targeted at motorists who need to know that they’re approaching a potential whiteout that could cause a deadly pileup accident like the one that occurred in Pennsylvania on Wednesday.

The National Weather Service created snow squall warnings as a way to warn people in the path of snow squalls that they could experience sudden whiteout conditions, giving them enough time to pull off the road and wait for things to calm down before driving again.

Source: NWS New York

A local NWS office can issue more than a hundred different types of watches, advisories, and warnings. Some of the products are more urgent than others. The most important warnings—the ones that require you to stop what you’re doing and pay attention to the weather instead—are usually issued using polygons, which allow forecasters to target warnings to only the areas at risk for life-threatening hazards like tornadoes and severe thunderstorms.

There’s a different target audience for each of those polygon-based warnings. Tornado warnings and severe thunderstorm warnings are “everyone” warnings, no matter who or where you are. Flash flood warnings are important to people who live in flood-prone areas and motorists who may approach a flooded roadway, but the vast majority of us can usually ignore them if we’re going about our business at home or work.

Beginning in November 2018, the National Weather Service officially began issuing polygon-based snow squall warnings, giving forecasters the ability to instantly warn people that they could be in the path of a sudden burst of snow. Snow squall warnings are “driver” warnings. They’re not targeted to people sitting in their living room or working at their cubicle. They’re targeted at people on the road or those who are getting ready to head out.

Snow squall warnings are handled with the same urgency as tornado and severe thunderstorm warnings for good reason.

Wow! Check out this time lapse of the #SnowSquall moving over Manhattan. Crazy cool view from the top of One World Trade Center. pic.twitter.com/K7kxjcA0Zt

— David Jones (@DavidJonesTV) December 18, 2019

We hear about pileup accidents all the time during the winter. A chain-reaction crash is pretty much the worst-case scenario for anyone out on the roads when a sudden burst of snow turns the roads to ice and drops visibility down near zero. Pileups can involve hundreds of cars in the most serious incidents, amassing dozens of injuries and fatalities as people get stuck in the wreckage and absorb the blow of every car and truck careening toward them.

The warnings worked exactly as expected on Wednesday. Several snow squalls moved across portions of the Northeast today, bringing whiteout conditions and dropping up to two inches of snow in under an hour. It doesn’t look like much on radar (shown at the top of the post), but the tweet above shows how abruptly a cloud of snow can drop visibility down near zero.

Unfortunately, a snow squall in central Pennsylvania actually did cause a deadly pileup on I-80 about 20 miles east of State College. The Daily Item reported that two people died and dozens more were injured during the chain-reaction crashes.

There’s only so much meteorologists can do to warn people of what’s on the horizon. Just like a tornado or severe thunderstorm warning, it’s not always possible to pull off the road or avoid a wreck when you find yourself driving into a snow squall. The new warnings are designed to give you an opportunity to seek safety that wasn’t available before. It’s all worth it if each warning helps even a couple of people stay safe.

[Top Image: Gibson Ridge]


You can follow me on Twitter or send me an email.

Please consider subscribing to my Patreon. Your support helps me write engaging, hype-free weather coverage—no fretting over ad revenue, no chasing viral clicks. Just the weather.
 

Author

Dennis Mersereau

I have 15+ of experience providing hype-free weather information for folks across the United States and around the world. In addition to DAMWeather, I also contribute to The Weather Network as a digital writer and weather specialist.

Follow Me
Other Articles
Previous

A Quick-Hitting Storm Will Bring Midwest Snows And Severe Thunderstorms To South

Next

This Was The Warmest Christmas On Record For Much Of The Midwest


Local ◈ UTC
Facebook | Bluesky
Instagram | Threads | Email
DAMWeather is now ad-free! Everyone benefits from engaging, hype-free weather coverage. Please consider supporting my efforts through Patreon:




Order The Skies Above today!

Bookshop.org || Barnes & Noble
Mountaineers Books || Amazon

My latest book, The Skies Above, is now available!

Did you know a puffy cloud can weigh millions of pounds? Or that every rainbow you see is unique to you?

Our atmosphere is full of spectacular sights that are always within your reach. Glistening layers of fog, gorgeous sunsets, and brilliant meteors flashing through the sky can light up even the calmest day.

The Skies Above, published by Mountaineers Books, is a celebration of what we overlook when we look up. I was thrilled to work with the editors and illustrators at Indelible Editions to share with you the quotidian beauty of our sky.

Order your copy now and learn about the wonders we take for granted every day.

I teamed up with the editors of Outdoor Life magazine to write The Extreme Weather Survival Manual, your guide to surviving and thriving in almost any weather condition. Whether you're an avid outdoorsperson or you enjoy watching the radar from the comfort of your home, you're sure to find helpful tips, advice, and new bits of knowledge in this fascinating book.

You can buy my book today through Amazon.
  • 2026 (34)
  • 2025 (49)
  • 2024 (59)
  • 2023 (43)
  • 2022 (57)
  • 2021 (71)
  • 2020 (83)
  • 2019 (88)
  • 2018 (92)
  • 2017 (1)
  • 2016 (4)
  • 2015 (10)

Copyright 2026 — DAMWeather. All rights reserved. Blogsy WordPress Theme