Can we get thunderstorms in the winter? The answer is yes! It happened just over a day ago after our first wintry system of the new year brought freezing rain, sleet, and eventually heavy rain showers overnight on Saturday to the area.
It’s rare to see thunderstorms in the winter, because they require precise conditions to take place that aren’t usually present during the colder season. Why?
Thunderstorms require warm, moist air to rise, a lifting mechanism such as a front, and an unstable air mass (air that will keep rising when given a nudge in one direction). This happens most frequently in the warmer, spring and summer months due to the abundance of these ingredients, and a beaming hot sun to heat up the ground to get things going. It’s not common during the winter to see the clash of warm and cold air masses like you would in the summer.
During the summer, thunderstorms usually form from growing convection at the surface caused by heat radiation from the sun. In the winter, colder air and less sunlight prevents this from happening, but if you get a warm enough layer within the atmosphere to be forced above a layer of colder air along a frontal boundary, you can get what’s called elevated convection.
How does this happen?
Elevated convection is just what it sounds like, it’s convection that’s elevated. This happens on the cool side of a front, usually a warm front. You can force warm air to move over colder air at the surface, because fronts are slanted as they approach. It’s not just a linear wall that plows through. This allows warmer air to slide up and over the colder air as the warm front pushes through which helps convection and storms to form along it like a conveyor belt.
Now, instead of the source of this convection originating from the surface, it’s coming from higher up in the atmosphere resulting from elevated instability.
Winter thunderstorms are much more common across parts of the mid and south Atlantic where the climate is slightly warmer, and where they still get occasional clashes of air masses to spark up storms. It’s much more difficult to get this to occur across anywhere in the Northeast since our climate during the winter is so much colder, which is why it’s so unique we saw this happen here in Western New York!
There also exists a phenomenon known as thunder snow, where you can get lighting and thunder to occur in a system that’s producing mainly snow as the precipitation. This typically happens within intense, snow squalls where there’s a lot of lift, or upward vertical motion present. When you have this quality in a storm, it’s known to have a strong updraft. If you have a strong enough vertical updraft within the squall you can get ice crystals within the clouds to generate enough friction to spark lightning, and therefore thunder.
Pretty neat, right?
~Meteorologist Christine Gregory