Rainfall patterns have shifted during the last 30 years, providing less productive showers in Southwest Florida and some other parts of the country.
That finding comes from AccuWeather, a commercial weather forecasting firm based in State College, Pennsylvania, known for its research on long-term climate trends.
The company studied humidity and rainfall records along with 70 years of temperature data collected at dozens of weather stations nationwide. Among other things, the analysis found that while the amount of rain has changed little overall, how and when it falls has shifted dramatically.
In Southwest Florida, that often means too much rain is coming too quickly.
The findings highlight a growing paradox in Southwest Florida and some other parts of the country: Heavy downpours and hurricanes may deliver needed water, but those deluges leave little time for that water to soak into farmer’s field, quench a drought-stricken region’s thirst, or percolate through the soil to refill the aquifers below.
“Total rainfall across the United States has actually diminished a little bit,” Brett Anderson, AccuWeather’s senior meteorologist, said. “Extreme rainfall — when we’re talking events of three or four inches over 24 hours — we’ve seen a significant uptick in those types.”
When water hits the ground faster than it can be absorbed, it runs into rivers, streams and aging drainage systems that were not built to handle so much. In nearly flat Florida, the runoff has plenty of time to collect nutrients and other pollutants as it travels downstream and into the ocean.
“It takes forever,” Anderson said. And that allows the water filled with nitrogen and phosphorous from fertilierts to wind up along the beaches or in the nearshore marine ecosystem, which can prolong an existing red tide.
He said the warmer atmosphere in Southwest Florida is holding more moisture, which in turn helps warm the oceans. Those conditions are extending the window for tropical storm development later into the fall and even into early winter.
Environmental reporting for WGCU is funded in part by VoLo Foundation, a non-profit with a mission to accelerate change and global impact by supporting science-based climate solutions, enhancing education, and improving health.
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