Does thunder in the winter mean snow in 10 days?
**UPDATED WITH THIS WINTER SO FAR**
So we had thunder today in Meteorological Winter so naturally I’ll start to get quetions about a certain folklore. I have heard the old folklore for years, that thunder in the winter means snow is coming. Though it appears to change depending on who tells it. Sometimes I’ve heard it as 7 days, 10 days or 14 days after thunder in the winter time that snow is coming. The general folklore though goes by 10 days from getting winter thunder you should get snow.
Some folklore can actually be based on a bit of science. This one isn’t entirely a crazy idea. If you think of the weather pattern that leads to thunder or thunderstorms in the winter. You usually have a strong cold front that is bringing in a colder pattern after a warm-up. So on its face, it kinda makes sense that it would turn colder after we get a strong cold front with thunderstorms in the winter. Though as you know getting cold is only half the equation for snow in the Carolinas.
What the data says.
So ever since hearing this, I always like to look back at the actual data to see how often it works out. So here’s the bad news. It only works about 11% of the time.
In the past 8 winters including last winter, I looked for all the time’s that thunder was reported at the airport. Yes, I’m sure someone hears thunder in other spots, but we have 24/7 365 reliable weather data that goes back 141 years here in Charlotte.
So I used the airport data for quality control. In the past 8 winters, I looked for when thunder was reported anytime of the day in the winter months of December, January and February. I found 52 sperate days where thunder was reported. Of those 52 days of thunder, only 6 times for sure did we have snow within 10 days. That means just in the past 8 winters this folklore only worked out 11% of the time.
Not to burst anyone’s dreams but in general, the whole thunder in winter then snow within 10 days thing. Just doesn’t stand up to the data. It’s fun to dream but in reality, it just doesn’t work out the way the saying goes. Now I’ve heard people argue it’s 14 days or some other criteria but that just makes it even less of a reality. If you need to adjust the rules for it to work then it’s not really much of a rule. 🙂
