June 2016: It Never Rains in Crozet!
By Heidi Sonen & Roscoe Shaw
When it starts to get dry, as it does almost every summer, Heidi and I hear the same complaints. “Everybody keeps getting rain except us. All the storms miss us! They always get the rain over there but not here.”
Actually, rainfall is very evenly distributed in central Virginia and the complaints are not true. But there’s a reason it seems this way. The typical afternoon thunderstorms are often nearly randomly distributed. But you can see them for many miles away and hear the thunder many miles away.
So it seems like everyone else is getting rain but not you. The reality is, the people a few miles away are getting missed as well and complaining just like you.
When you look at monthly rainfall totals, they are often wildly different from one place to another. But over time it evens out. The mountains average slightly higher rainfall but everywhere else is about the same.
You also have to be careful what you wish for. Summer heat creates a lot of demand for water so usually you want more rain. But the recent floods in West Virginia show you can get way too much way too fast sometimes.
Forecasting has challenges in the summer thunderstorm season as well. Individual thunderstorms usually last less than an hour and grow and shrink and move, making them difficult to forecast. About the only thing you can do is forecast probabilities of storms at different times of day.
One thing you can be sure of is that in summer, thunderstorms are very likely at 6 p.m. and very rare at 6 a.m. That is because thunderstorms thrive on heat and the sun provides increasing fuel as the day goes on.