Water sensors across the region reached stunningly hot temperatures in recent days, with temperatures around the Florida Keys measuring between 92 and 96 degrees Fahrenheit (33-35 Celsius), and similar temps in littoral areas along the US’ southern coast.
“That’s boiling for them! More typically it would be in the upper 80s,” tweeted Jeff Berardelli, the chief meteorologist and climate specialist at a Tampa television station.
“Typically Florida sees a nice breeze from the [southeast] but this summer pattern has been resilient,” Berardelli explained, explaining that winds can stir up the seas, bringing up colder water from the deep. “The water is warming under this stagnation!”
The high water temps are being pushed upward by a record-breaking heat wave across the region, with high humidity pushing Miami’s heat index up to 110 degrees Fahrenheit on Monday. It’s been above 100 Fahrenheit for weeks.
However, the unusual warming trend has been noted in the Gulf since February.
The 2023 Atlantic hurricane season officially began on June 1 and lasts until December, and while three tropical storms have been tracked so far - more than normal none have reached hurricane intensity. Still, meteorologists were already warning that 2023 could be an overactive year for tropical cyclones, fanned not only by a Pacific El Niño, but a rare Atlantic or “Dakar Niño,” named for the Senegalese city on the African coast where the warmer-than-normal waters can be found.
“The Gulf of Mexico is like a powder keg,” said meteorologist Matthew Cappucci. “We can't guarantee that a storm will spark up, but if one does, there is copious oceanic heat content – fuel – to help it overachieve.”
In recent years, ultra-warm waters in the Gulf have been blamed for several hurricanes experiencing “bombogenesis,” or rapid intensification as they approached landfall. Hurricane Michael in 2018, Hurricane Laura in 2020, and Hurricane Ian in 2022, all strengthened dramatically as they approached the US Gulf Coast.
The high heat is something being experienced across the US, not just in Florida. Phoenix, Arizona, experienced its 10th day above 110 degrees Fahrenheit on Tuesday, and Death Valley, California, is expected to reach 130 degrees. Temps in California’s Central Valley won’t be much cooler, and in the Mid-Atlantic temperatures are settling into the mid-to-upper 90s. Some 90 million Americans are under heat alerts.
Globally, last week the Earth shattered its record for hottest day three separate times, marking the highest global average temperature seen in 120,000 years.