ROANOKE, Va. – It’s been fun for me to hear about or learn some of the weather wives’ tales that have been passed down from generation to generation. One of the big ones I often hear is the one regarding thunderstorms in winter.
[Do you believe it? Click here to take our poll]
Recommended Videos
Depending on who I hear this one from, it’s either that it’ll snow 7, 10 or 14 days after hearing thunder. I wanted to put this to the test in our part of Virginia.
In the past decade (2012 to 2022), it worked out four out of 16 times (25%) that snow would follow 7-10 days after thunder.
1. How’d we perform this test?
Iowa State University has a database that collects more weather data than just high and low temperatures and precipitation. I went into this database and researched when we saw thunder during the months of December through March.
From there, I wanted to see if there was measurable snow the following week. I went to another (more user-friendly) database to research that.
2. What did we find?
In analyzing the winter months from 2012 to 2022, I found there were 16 occurrences of thunder in the Roanoke Valley. There were four instances seven-to-ten days afterward in which we saw measurable snow (0.1″ or more).
It happened once in 2012, once in 2013 and once in 2018.
We also found that it was more common for thunder to happen in February and March than it was for it to happen in December and January. This makes sense, as we gain more daylight and start to transition into the warmer season.
While we’ve been in a snow drought of sorts this winter, it’s important to remember that there’s still plenty of winter to go.
On average, 45% of our annual snowfall comes after January.
3. Why might snow follow thunderstorms?
This all has to do with the positioning of the jet stream.
The jet stream is not only your dividing line between cold air and mild air in the winter, but it’s often referred to as a “storm track.” It’s the railroad for storm systems to ride along.
When you hear thunder or see lightning in the winter, you’re on the more mild side of the jet stream. That often means there’s colder air in the western half of the country.
So if the jet stream then dips in the Eastern U.S., we get colder. If a storm then rides that railroad, we’re in business for snow not long after being mild with storms.
4. Will we see snow in the next 7-10 days?
Like real-estate and a pitch in baseball, it’s all about location, location, location.
Most of our west-facing slopes see snow Friday into Saturday. As for a large majority of the area, we won’t see anything measurable for at least the next week.
The pattern beyond Martin Luther King Day has us on that warm side of the jet stream again.
If snow is ever part of the forecast, you’ll be the first to know by downloading our free 10 News and weather apps here.
Want more extra content like this? Check out our weekly newsletter, ‘Beyond the Forecast’ below: