A hurricane so small that it could not be observed by satellite formed this weekend, surprising meteorologists and even forecasters at the National Hurricane Center.
Hurricane Oscar developed on Saturday near Turks and Caicos, and to the northeast of Cuba, in the extreme southwestern Atlantic Ocean. As of Saturday evening, hurricane-force winds extended just 5 miles (8 km) from the center of the storm.
This is not the smallest tropical cyclone—as defined by sustained winds greater than 39 mph, or 63 kph—as that record remains held by Tropical Storm Marco back in 2008. However, this may possibly be the smallest hurricane in terms of the extent of its hurricane-force winds.
On October 10, 2018, Tyndall Air Force Base on the Gulf of Mexico—a pillar of American air superiority—found itself under aerial attack. Hurricane Michael, first spotted as a Category 2 storm off the Florida coast, unexpectedly hulked up to a Category 5. Sustained winds of 155 miles per hour whipped into the base, flinging power poles, flipping F-22s, and totaling more than 200 buildings. The sole saving grace: Despite sitting on a peninsula, Tyndall avoided flood damage. Michael’s 9- to 14-foot storm surge swamped other parts of Florida. Tyndall’s main defense was luck.
That $5 billion disaster at Tyndall was just one of a mounting number of extreme-weather events that convinced the US Department of Defense that it needed new ideas to protect the 1,700 coastal bases it’s responsible for globally. As hurricanes Helene and Milton have just shown, beachfront residents face compounding threats from climate change, and the Pentagon is no exception. Rising oceans are chewing away the shore. Stronger storms are more capable of flooding land.
In response, Tyndall will later this month test a new way to protect shorelines from intensified waves and storm surges: a prototype artificial reef, designed by a team led by Rutgers University scientists. The 50-meter-wide array, made up of three chevron-shaped structures each weighing about 46,000 pounds, can take 70 percent of the oomph out of waves, according to tests. But this isn’t your grandaddy’s seawall. It’s specifically designed to be colonized by oysters, some of nature’s most effective wave-killers.
As attempts to clean up after Hurricane Milton are beginning, scientists at the World Weather Attribution project have taken a quick look at whether climate change contributed to its destructive power. While the analysis is limited by the fact that not all the meteorological data is even available yet, by several measures, climate change made aspects of Milton significantly more likely.
This isn't a huge surprise, given that Milton traveled across the same exceptionally warm Gulf of Mexico that Helene had recently transited. But the analysis does produce one striking result: Milton would have been a Category 2 storm at landfall if climate change weren't boosting its strength.
From the oceans to the skies
Hurricanes strengthen while over warm ocean waters, and climate change has been slowly cranking up the heat content of the oceans. But it's important to recognize that the slow warming is an average, and that can include some localized extreme events. This year has seen lots of ocean temperature records set in the Atlantic basin, and that seems to be true in the Gulf of Mexico as well. The researchers note that a different rapid analysis released earlier this week showed that the ocean temperatures—which had boosted Milton to a Category 5 storm during its time in the Gulf—were between 400 and 800 times more likely to exist thanks to climate change.
Hurricane Helene crossed the Gulf of Mexico at a time when sea surface temperatures were at record highs and then barreled into a region where heavy rains had left the ground saturated. The result was historic, catastrophic flooding.
One key question is how soon we might expect history to repeat itself. Our rapidly warming planet has tilted the odds in favor of some extreme weather events in a way that means we can expect some events that had been extremely rare to start occurring with some regularity. Our first stab at understanding climate change's influence on Helene was released on Wednesday, and it suggests that rainfall of the sort experienced by the Carolinas may now be a once-in-70-year event, which could have implications for how we rebuild some of the communities shattered by the rain.
Rapid attribution
The quick analysis was done by the World Weather Attribution project, which has developed peer-reviewed methods of looking for the fingerprints of climate change in major weather events. In general, this involves identifying the key weather patterns that produced the event and then exploring their frequency using climate models run with and without the carbon dioxide we've added to the atmosphere.
In less than a day, Hurricane Milton has rapidly intensified over the southern Gulf of Mexico, exploding from a small Category 1 hurricane into a Category 5 storm. Unfortunately, the hurricane is likely to strengthen further as it tracks eastward toward Florida.
The National Hurricane Center reported that Milton had reached sustained winds of 160 mph as of 11:44 pm ET on Monday, with a central pressure of 925 millibars. The storm is moving steadily eastward and is likely to reach the west coast of Florida on Wednesday evening as a major hurricane.
Based upon Atlantic basin records, Milton has tied Hurricane Maria (2017) for the second-fastest intensification from a Category 1 to Category 5 hurricane, taking just 18 hours. Only Hurricane Wilma (2005) did so more rapidly, in just 12 hours.
As often happens during the month of July, the Atlantic tropics entered a lull after Hurricane Beryl struck Texas and short-lived Tropical Storm Chris moved into Mexico. But now, with African dust diminishing from the atmosphere and August well underway, the oceans have awoken.
Tropical Storm Debby formed this weekend, and according to forecasters with the National Hurricane Center, the system is likely to reach Category 1 hurricane status before making landfall along the coastal bend of western Florida on Monday.
As hurricanes go, this is not the most threatening storm the Sunshine State has seen in recent years. Yes, no one likes a hurricane, or the storm surge it brings. But Debby is likely to strike a relatively unpopulated area of Florida, venting much of its fury on preserves and wildlife areas. This won't be pleasant by any means, but as hurricanes go this one should be fairly manageable from a wind and surge standpoint.
I'll readily grant you that Houston might not be the most idyllic spot in the world. The summer heat is borderline unbearable. The humidity is super sticky. We don't have mountains or pristine beaches—we have concrete.
But we also have a pretty amazing melting pot of culture, wonderful cuisine, lots of jobs, and upward mobility. Most of the year, I love living here. Houston is totally the opposite of, "It's a nice place to visit, but you wouldn't want to live there." Houston is not a particularly nice place to visit, but you might just want to live here.