It’s hot. Not just "Miami in July" hot. It’s historically, hellaciously hot in South Florida and around the world.
We’re just starting to experience the impacts from the heat.
Earlier this hurricane season we saw two named tropical storms form east of the Antilles in June. That’s the first time that has ever happened dating back to 1851, the year reliable recordkeeping began. When Tropical Depression Three (Tropical Storm Bret’s predecessor) formed, it became the easternmost tropical cyclone to form in the Atlantic in the month of June.
A record-hot Atlantic Ocean is to blame for the fast start to hurricane season.
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Thankfully, in July, westerly winds aloft have picked up in intensity across the Caribbean and Main Development Region of the tropical Atlantic. The wind shear these westerlies produce has been strong enough to keep other storms from forming. We can thank the fledgling El Niño for those stronger winds aloft, and can only hope that they continue into August and September.
However, seasonal forecasting experts are worried that the shear won’t be enough to suppress storms and hurricanes in 2023. At Colorado State University (CSU), the entity with the longest track record of hurricane season forecasting, they’ve gone from an April 2023 outlook of 13 tropical storms, to 15 storms in their June forecast, to now 18 named storms in the latest update published on July 6.
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What was forecast to be a season with 20 percent less Accumulated Cyclone Energy (ACE) — a metric that combines the strength, number and longevity of storms and hurricanes — is now expected to be 30 percent above normal, according to CSU.
As I’ve written before, expect surprises this hurricane season. So far, they haven’t been pleasant. But impacts from excessive heat extend well beyond what might happen with tropical systems this year.
The marine heatwave being observed across the Atlantic has spiked in the Caribbean, Gulf of Mexico, and the nearby waters that surround Florida. To the east, south, and west of the peninsula, sea surface temperatures are running 5 to 7 degrees Fahrenheit above the most-recently calculated (1991-2020) 30-year normal. In the Florida Keys, water temperatures at Murray Key and Johnson Key are at 97 and 95 degrees respectively.
As a result of these silly-hot water temperatures, the National Oceanic and Atmospheric Administration (NOAA) is forecasting a near 100% chance of coral bleaching throughout Florida, the Bahamas, the Antilles, and far east into the Atlantic.
Meanwhile, Miami-Dade County is setting a new record this year for the highest number of Heat Advisories issued by the National Weather Service (NWS). While this is in part because the criteria for advisories was set at heat index values of 105°F or higher starting this summer, the main culprit for so many public warnings about the heat threat is simply that it’s hotter than it’s ever been.
University of Miami Senior Research Associate Brian McNoldy has been keeping close track on the heat index values in Miami so far this year. Stunningly, as of July 10, the city had already spent more time above a 105°F feels-like temperature than it ever has in an entire year!
According to NWS in Miami, "significant health impacts" can occur when the heat index is 105 °F or higher. Heat-related illnesses include heat exhaustion and the often-lethal heat stroke, characterized by a rapid rise in body temperature. The very young, the elderly, people with pre-existing medical conditions, and outdoor workers are at higher risk of succumbing to the heat.
Knowing that there was a growing chance for an El Niño in 2023 led many scientists, including me, to correctly predict that this year would become the hottest humans had ever lived. What we didn’t know was just how quickly it would become so dangerously hot.
Recently, the term “new normal” is being thrown around rather nonchalantly. It’s important to remember just how abnormal this is — and what we’ve gotten ourselves into.
We know what the solutions to unbridled global heating are. We just need to implement them, stat!
John Morales is NBC6's hurricane specialist.
