More than one friend sent me a link to a Yahoo! story today about how rainy forecasts are misunderstood. The article contends that only half of the population fully understands what the visual forecast icons and percentages mean.

What do I mean by visual forecasts?

Tuesday has a 50% chance of showers. What does that even mean? Let’s look at another example.

Monday and Tuesday of next week have a 40 and 50 percent chance of rain, respectively.

What confused people is what the percentage actually stands for. Many surveyed thought by saying “there is a 50% chance of rain” means that it will rain for half the day or only half the area will get rain. Although I can see what they are thinking, they are unfortunately wrong. The saying “50% chance” means given the atmospheric conditions at this time, half the time it rains and half the time it doesn’t.

As seen in the survey, this is a very common misconception. Meteorologists may not do a good enough job explaining this feature of the forecast. Some people don’t even use “chances of” on their extended forecasts.

My former boss at WTNH and good friend Geoff Fox never puts percentages on his 8-day forecasts. It is misleading to people, he would say. It took me a couple of days to understand what he meant.   A good communicator is just as powerful as an icon. Geoff does a great job of explaining each tricky forecast so not to mislead any viewers.

Next time you hear “there is a chance of rain” you’ll know what the meteorologist is talking about…even if we are only right 50% of the time.