Forecasting Change: Wet days getting wetter

Warmer atmosphere holds more moisture

ORLANDO, Fla. – This week on Forecasting Change we’re focusing on heavy precipitation.

So many folks think of a changing climate as simply the earth getting warmer and the ice melting, but there are impacts that you might not think of. Primary among them: heavy rain.

Since 1950, nearly 75% of the locations evaluated in the U.S. have seen their wettest day occur. In even more areas, at least 15% of all reporting stations had a top 10 wettest day in the year 2021. In that 15%, 37 had the highest daily rain total ever.

The blue dots represent a top ten wettest day. The green dots represent an all time wettest day.

The bottom line is a warmer atmosphere has more room to hold more moisture. The increased temperature also evaporates more water. All that moisture available becomes a problem when storms have fuel to deliver.

Below, look at the pattern for Orlando over the last seven decades.

Orlando rain
Orlando rain

In other spots it has been even more remarkable. Here is Gainesville:

Gainesville rain

The same holds true for Tampa:

Tampa rain

As the Earth continues to warm, remember that for every 1-degree F, the atmosphere can hold about 4% more moisture. In the end, the current rainfall records will continue to fall as the Earth gets warmer.

About the Author:

Tom Sorrells is News 6's Emmy award winning chief meteorologist. He pinpoints storms across Central Florida to keep residents safe from dangerous weather conditions.