Winter Weather: Snow Squalls
By: Marina Kobasiuk
Snow squalls are a specific type of winter storm that are not new, but predicting them has been difficult due to a variety of reasons. Squalls, no matter the precipitation type, are described as narrow bands of convective storms with intense winds. They form and dissipate quickly and can either track ahead of a larger system or be a localized event, but are often tied to strong cold fronts. As a result, the exact atmospheric conditions that can trigger their life cycle has been a focus by meteorologists in order to improve forecasting.
It can be easy for winter weather terminology to get confusing though, especially since snow squall forecasts were not issued by all weather service offices until recently. And they can often be compared to blizzards due to the similarities in what they do to visibility. These storms, however, are not exactly the same as blizzards due to their short life span. Blizzards require three hours or more of sustained winds and squalls will complete their passage in under an hours time. Squalls often are associated with precipitation, though if the snow accumulates can depend on the local conditions before the snow begins. Warmer surface temperatures can reduce accumulation but the speed and quantity can still result in inches of snow remaining after a storm has finished. Blizzards, however, can occur with or without snowfall since the necessary low visibility can come from falling snow, or previously deposited snow that is being blown back into the air by the constant winds and strong gusts.
These extreme conditions are brief but can cause significant damage and loss of life; notably on roadways where people are unable to take shelter and there is no way for people to accommodate for the sudden change in weather. In an effort to minimize this NOAA began testing a process of issuing warnings for snow squalls, which was why only selective offices were issuing these forecasts until the winter of 2018-2019 when the program went nationwide, just in time to get plenty of potential uses with the intense cold the nation saw with the trend of low temperatures and storms associated with the polar vortex in January. As the winter continues the weather service may or may not see more use of this particular warning, but now it can be used anywhere that these conditions may develop, and in an effort to keep people safer this is an excellent improvement to see in winter weather forecasting and safety.
References:
“Snow Squall Warnings Now Available Nationwide.” National Oceanic and Atmospheric Administration, www.noaa.gov/stories/snow-squall-warnings-now-available-nationwide.
US Department of Commerce, and Noaa. “Snow Squall.” National Weather Service, NOAA’s National Weather Service, 20 Apr. 2018, www.weather.gov/safety/winter-snow-squall.