If you are a regular viewer of weather forecasts on television, you have probably heard the meteorologists mention isolated or scattered thunderstorms.
Well, what exactly does that mean? In general, a 10% to 20% chance for precipitation translates into isolated thunderstorms. This means that most people will remain dry, while just a few areas may see some rain. A 30% to 50% chance for precipitation generally means scattered thunderstorms. Again, not everybody will see rain.
When the rain chances hit 60% or higher, we will generally say that rain or snow is likely and most of the forecast area will see precipitation, especially when the chances are at 70% to 90%. Sometimes you may hear us say a good chance for precipitation and that translates to about a 50% chance for precipitation. A lot of times I will get asked, “Will it rain tomorrow; I have an outside wedding planned.”
I then say; “Well it looks like about a 30% chance for thunderstorms.” They will then ask, “Well, will it rain or not”? And I say; “the odds are in your favor that it won’t rain, but there is that small chance.” Now I know that can be frustrating and while forecasting technology has improved dramatically over the last several years, it has not advanced to the point where we can actually say that there is a 100% chance of rain in your neighborhood and a 0% chance for rain across town.
Hopefully some day! Some stay away from percentages altogether, using words like “small chance” or ” storms likely”. Just another way to do it!