November 17, 2021

PEMA Digital Newsletter

Snow Squall Safety

Snow Squall Safety


When you think of winter weather hazards, what comes to mind? Do you think of big snowstorms that drop a significant amount of snow? Do you think of ice storms that cover trees, powerlines, and roadways in a glaze of ice?

Or maybe you think of flooding that can occur when a storm drops heavy rain on top of melting snow, overwhelming creeks, streams, and rivers with water.

Pennsylvania sees many forms of hazardous winter weatherWe are going to talk about snow squalls.

A snow squall is a brief but intense period of heavy snow (up to 2 inches in 30 minutes), strong winds (30+ mph) and whiteout conditions (visibility less than 1/4 mile). Snow squalls often occur on days with otherwise partly cloudy skies. Coming on so suddenly, snow squalls can catch drivers off guard and lead to major transportation impacts, including deadly multi-vehicle accidents.

Winter Weather Awareness

The seasons are a changing - winter is on the way. The National Weather Service is forecasting above-average warmth and slightly above average precipitation for December through February.

With a La Niña pattern expected over the winter, Pennsylvania winters tend to include more frequent and “warmer” storms, often producing a mix of rain, sleet, ice, and snow. So, before you stock up on salt, put the winter tires on, and fuel up the snow blowers, take a second to refresh on these winter weather terms.

Winter Weather Terminology

  • Blizzard: Sustained winds or frequent gusts of 35 mph or more with snow and blowing snow frequently reducing visibility to less than a quarter-mile for three hours or more.
  • Blowing Snow: Wind-driven snow that reduces visibility. Blowing snow may be falling snow and/or snow on the ground picked up by the wind.
  • Snow Squalls: Brief, intense snow showers accompanied by strong, gusty winds. Accumulation may be significant.
  • Snow Showers: Snow falling at varying intensities for brief periods of time. Some accumulation is possible.
  • Flurries: Light snow falling for short durations with little or no accumulation.
  • Freezing Rain: Rain that freezes when it hits the frozen objects near the ground; creating a coating of ice on roads, walkways, trees and power lines.
  • Sleet: Rain that freezes into ice pellets before reaching the ground. Sleet also causes moisture on roads to freeze and become slippery.

Know Your Winter Weather Alerts 

When a hazardous storm is forecast to arrive in a day or two…

  • Winter Storm Watch: Issued for the possibility of a blizzard, heavy snow, heavy freezing rain or heavy sleet.
  • Wind Chill Watch: Issued for the possibility of wind chill temperatures dropping low enough to be hazardous to life within several minutes of exposure.

When a hazardous storm is occurring or less than a day away…

  • Winter Weather Advisories: Issued for accumulations of snow, freezing rain, freezing drizzle and sleet which will cause significant inconveniences and, if caution is not exercised, could lead to life-threatening situations.
  • Winter Storm Warning: Issued when hazardous winter weather in the form of heavy snow, heavy freezing rain or heavy sleet is imminent or occurring.
  • Ice Storm Warning: Significant icing is expected to produce downed utilities, trees and create treacherous travel.
  • Blizzard Warning: Issued for sustained or gusty winds of 35 mph or more and falling or blowing snow creating visibilities at or below ¼ mile; these conditions should persist for at least three hours.
  • Lake Effect Snow Warning: Widespread or localized lake-induced snow squalls or heavy snow showers which produce significant snowfall accumulation in less than 12 hours.
Wind Chill Warning: Issued when wind chill temperatures are expected to be hazardous to life within several minutes of exposure.

Sign up for Alerts

AlertPA

Join the AlertPA notification system by CodeRED for emergency and weather related alerts, health notifications, building alerts and other updates from commonwealth and federal agencies.

A CodeRED Weather Warning will automatically alert you through the AlertPA notification system if your address falls in the path of severe weather, as determined by the National Weather Service.

511PA

Winter weather will soon be here. Did you know you can receive your own Personal Travel Alerts? It’s easy to sign up and customize your alerts: Where you want them… When you want them… What roadways you want!

Don’t want alerts on the weekend? No problem! Just set your alerts on weekdays only or before your daily commute.511PAprovides traffic delay warnings, weather forecasts, traffic speed information and access to more than 860 traffic cameras.

We are encouraging you to "Know Before You Go" by checking conditions on more than 40,000 roadway miles by visiting511PA. It is free and available 24 hours a day. 511PA is also available through a smartphone application for iPhone and Android devices, by calling 5-1-1, or by following regional Twitter alerts accessible on the511PAwebsite.

Sign up for both AlertPA and 511PA today!