Just over a month ago, hurricane forecasters were saying the upcoming hurricane season was going to be slightly below normal in terms of the number of storms. Now, they're anticipating slightly above normal — and it's all because of warm waters in the Atlantic Ocean, which are ripe for the rapid intensification of storms.
This year in particular, the water off the Florida coast is less of a reprieve from the heat as it is just another source of it.
Rosa Lamela is the executive director of the Mark Sorensen Youth Sailing Program in Key Largo, and it's even been too much for her, a 20-year native of the area.
"It seems like we've been under a heat advisory for the last two or three weeks," Lamela said.
Florida is experiencing one of its hottest summers in recent memory. Miami has seen a heat index of more than 100 degrees for 30 straight days.
But the same goes for the water, which has seen some of its warmest readings on record.
Across the Florida Keys, water temperatures are anywhere between 1 and 5 degrees warmer than normal. In Bob Allen, Florida, for example, the water is in the mid-90s, when it usually averages nearly 88 degrees (87.9) Fahrenheit. Those five degrees might not sound like much, but to scientists, it is.
Climate researchers predicting above-average hurricane season
Researchers from Colorado State University have increased their hurricane season forecast.
"It doesn't seem like a lot but small temperature changes make big differences in how the atmospheric circulation responds, and that's obviously critical for what happens with the hurricanes," said Phil Klotzbach.
Klotzbach is a senior research scientist at Colorado State University, one of the country's most highly regarded hurricane prediction centers. In late May his group predicted 15 named storms this season with seven of them being hurricanes, but because of the record warm waters in the Gulf and the Atlantic they updated those numbers last week to 18 named storms with nine hurricanes. Those numbers would make this year an above-average hurricane season.
"Given how warm the Atlantic is — that certainly has given me a lot of pause when trying to do these seasonal forecasts because normally in an El Nino year we'd be forecasting a below-normal hurricane season, but because the Atlantic is so warm we're now forecasting a little bit above-normal hurricane season," Klotzbach said.
One of the main reasons for that warmth is a lack of trade winds that circle the Earth near the equator. Normally those winds churn the ocean, bringing colder water to the top, but a milder season has caused the warmer water heated by the sun to stay up top. If a hurricane does form, that warm water would then act as generator for stronger storms like Hurricane Ian which battered the Florida coast last fall after undergoing rapid intensification.
The warm air doesn't help either. On Tuesday it was still 86 degrees even after the sun had set. All that warmth allows that water surface temperature to rise even further.
