When I was on Bob and the Showgram this morning, a very nice lady called in to ask me the following question: "I heard that if there is snow on the ground for 3 days, it will snow again in 10 days. Is there any truth to this old wives tale?"
Wow. What a great question! I've heard a lot of those weather-lore stories, but this one was new to me. I told her I would answer it here. So here you go ...
First of all, the most famous weather folklore story I hear this time of year is: "If there's thunder in the winter, we'll have snow 7-10 days later."
That one is mostly false. I went through the data for the Triangle for the past 30 years and found out that only happens about 3 out of 10 times.
The great folks at the North Carolina State Climatologist's office found that statewide it's even less.
In their study, it was only 13 percent of the time. You can find more on their study, here.
One of the oldest weather folklore stories goes something like this: Red Sky in the morning, sailor take warning. Red sky at night is a sailor's delight! Or some variation. Though it's not always correct, for those of us that live where the weather generally moves west to east, it can be TRUE most of the time. Here's why.
For the sky to be red in the morning, it would have to be clear in the east.
As the sun was rising in the east, it would reflect off the clouds (from the approaching storm) in the west.
For it to be true in the evening, those clouds would have to be moving away with a clear sky in the west for the sun to set into. Calmer weather would be moving in.
The origin of the saying can actually be traced back to the Bible. In the book of Matthew, Jesus says "When evening comes, you say, 'It will be fair weather, for the sky is red,' and in the morning, 'Today it will be stormy, for the sky is red and overcast.'"
Let's get back to the snow on the ground question.
I checked with several meteorologists I knew, including a life-long North Carolina resident, and NONE of them were familiar with the saying.
I can theorize, however, why it may have come about.
If snow is on the ground for 3 days here, that means we're in some pretty cold air.
For cold air to stick around, we need to be in a cold weather pattern. And if a system with a lot of moisture runs into a cold weather pattern, it can drop more snow.
With all of that being said, my short answer to the question of "is this true?" is I really don't know.
That being said, I'll start going back through some weather records, and I'll let you know if I come across any patterns.
I'll also be watching what the weather will do on February 3rd and 4th. That is about 10 days out from 3 days of snow on the ground. For now, the search continues ...