After several days of whirling across the Gulf of Mexico, blowing at up to 180 miles per hour, Hurricane Milton is tearing toward Florida as the terrible embodiment of a historically destructive season. Milton inflated at a near-record pace, growing from a Category 1 storm into a Category 5 behemoth in half a day, to become one of the most intense hurricanes in recorded history. The hurricane had already dispatched plenty of dangers, including at least five tornadoes, before weakening to Category 3 ahead landfall, which is expected tonight or early tomorrow morning. And the worst is still yet to come for millions of people in its path.

The 2024 Atlantic hurricane season was forecast to be monstrous, but what has actually happened is something more nuanced—and stranger. July began with Hurricane Beryl, a Category 5 storm that emerged much earlier than any other in history. Then, what should have been the busiest part of the season was instead eerily quiet. It was “fairly surprising,” Emily Bercos-Hickey, a research scientist at the Lawrence Berkeley National Laboratory, told me. Then, beginning in late September, came a tremendous burst of activity: Hurricane Helene, which broke storm-surge records in Florida and unleashed devastating rains far inland; a flurry of named storms that spun up in quick succession; and now Milton.

Hurricane experts are still trying to understand why the current season is so scrambled. The extreme storm in July, the sudden lull during the traditional hurricane peak in late August and early September, and the explosion of cyclones in October together suggest that “the climatological rules of the past no longer apply,” Ryan Truchelut, a meteorologist in Florida who runs the consulting firm WeatherTiger, told me. For Truchelut, who has been in the business for 20 years, “there is a dreamlike unreality to living through this time,” as if he’s no longer living on the same planet he grew up on. During that summer lull, this hurricane season seemed like it might be a welcome bust. Instead, it is an indication that our collective sense of how hurricane season should proceed is fast becoming unreliable.

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The dire forecasts for the 2024 hurricane season were based on variables that are familiar to experts. This summer, Earth entered La Niña, which weakens the winds that can prevent hurricanes from growing too strong or forming at all. Meteorologists warned that record-high ocean temperatures across the tropical Atlantic and the Gulf of Mexico, along with the moisture stockpiled in our warming atmosphere, would fuel intense storms: four to seven major hurricanes compared with the usual three. Already, the 2024 season has conjured four major hurricanes. And it doesn’t end until November.

The mid-season lull, by contrast, was unexpected. Meteorologists also seem to have overpredicted the overall number of named storms—17 to 25 were forecast, and so far only 13 have arrived—though, again, there’s still time. “All the ingredients can be in place for an active or inactive season, but it’s the week-to-week variability that we can’t predict, but which often controls what happens,” Jeff Masters, a hurricane expert in Michigan who previously worked for NOAA, told me. Many Atlantic hurricanes are fueled by atmospheric conditions along the coast of western Africa. But this summer, the region stifled hurricane formation instead, thanks to an unprecedentedly heavy monsoon season. Scientists understand the basic mechanics of the quiet period. What experts can’t say, right now, is whether this scenario occurred because of natural happenstance. “We don't know for sure if that’s going to continue to happen with a warmer climate,” Bercos-Hickey said.

The summer hiatus isn’t the only way that this hurricane season has surprised meteorologists: More hurricanes than usual are making landfall in the mainland United States. After Milton, the season will be one more landfall away from tying the existing record of six. Hurricane experts have chalked this up to simple bad luck, just one more variable of hurricane activity that we can't do anything about. But humans bear some responsibility for the fact that the hurricanes that arrive are, on average, worse. Preliminary studies suggest that climate change made Helene 10 percent rainier and 11 percent windier. “Eleven percent may not seem like much, but the destructive power of a hurricane increases by 50 percent for every 5 percent increase in the winds,” Masters said. Scientists believe that global warming is making hurricanes intensify more rapidly, too. Milton, Helene, and Beryl all underwent rapid intensification this year.

[Read: Milton is the hurricane that scientists were dreading]

This hurricane season may be charting slightly behind predictions, but “if we look at actual impacts instead of general metrics, it has been a catastrophic year,” Brian McNoldy, a senior research scientist at the University of Miami, told me. In Florida, residents had just begun cleaning up from Helene’s wrath when Milton emerged. Two weeks is not nearly enough time between two major storms, each one dialed up to unleash more water, whether from the skies or the seas, than they likely would have several decades ago. Meteorologists cannot perfectly predict the trajectory of any given hurricane season—too much is up to chance. Now, in Florida, millions of people are waiting to see what the odds will mean for them.

As Hurricane Milton exploded from a Category 1 storm into a Category 5 storm over the course of 12 hours yesterday, climate scientists and meteorologists were stunned. NBC6’s John Morales, a veteran TV meteorologist in South Florida, choked up on air while describing how quickly and dramatically the storm had intensified. To most people, a drop in pressure of 50 millibars means nothing; a weatherman understands, as Morales said mid-broadcast, that “this is just horrific.” Florida is still cleaning up from Helene; this storm is spinning much faster, and it’s more compact and organized.

In a way, Milton is exactly the type of storm that scientists have been warning could happen; Michael Wehner, a climate scientist at Lawrence Berkeley National Laboratory, in California, called it shocking but not surprising. “One of the things we know is that, in a warmer world, the most intense storms are more intense,” he told me. Milton might have been a significant hurricane regardless, but every aspect of the storm that could have been dialed up has been.

A hurricane forms from multiple variables, and in Milton, the variables have come together to form a nightmare. The storm is gaining considerable energy thanks to high sea-surface temperatures in the Gulf of Mexico, which is far hotter than usual. And that energy translates into higher wind speeds. Milton is also taking up moisture from the very humid atmosphere, which, as a rule, can hold 7 percent more water vapor for every degree-Celsius increase in temperature. Plus, the air is highly unstable and can therefore rise more easily, which allows the hurricane to form and maintain its shape. And thanks to La Niña, there isn’t much wind shear—the wind’s speed and direction are fairly uniform at different elevations—“so the storm can stay nice and vertically stacked,” Kim Wood, an atmospheric scientist at the University of Arizona, told me. “All of that combined is making the storm more efficient at using the energy available.” In other words, the storm very efficiently became a major danger.

That perfect combination—of hot seas, humid air, and little wind shear—is being aided by Milton’s path through the Gulf of Mexico’s western part, which hasn’t seen much major storm activity yet this season. When a storm passes over hot water, it sucks up much of that heat, using it as fuel and lowering the water temperature. But in the western gulf, “nothing else had been there to cool off the water,” Wood told me.  

Milton is also a very compact storm with a highly symmetrical, circular core, Wood said. In contrast, Helene’s core took longer to coalesce, and the storm stayed more spread out. Wind speeds inside Milton picked up by about 90 miles an hour in a single day, intensifying faster than any other storm on record besides Hurricanes Wilma in 2005 and Felix in 2007. Climate scientists have worried for a while now that climate change could produce storms that intensify faster and reach higher peak intensities, given an extra boost by climate change. Milton is doing just that.

Rapid intensification has become more common in recent years. Hurricane Otis, which made landfall near Acapulco, Mexico, last year as a Category 5 intensified from a tropical storm in a single day, confounding forecasters and leaving residents very little time to prepare for a direct hit of that magnitude. Hurricane Idalia, also in 2023, was another example of rapid intensification, as was 2022’s Hurricane Ian. Kerry Emanuel, a meteorologist and professor emeritus at MIT, predicted less than a decade ago that hurricanes’ rapid intensification just before landfall was likely to become “increasingly frequent and severe as the globe warms,” and in the past few years, that prediction has borne out in additional modeling studies. It’s a new addition to the canon of climate-change knowledge, so it’s not yet firmly established, but this early research points toward a connection between rising temperatures and these storms’ rapid escalation. Climate change might actually decrease the total number of tropical storms and hurricanes (though the mechanism causing that decrease is still being debated), but the storms that do manage to form will likely be more intense, according to Tom Knutson, a senior scientist at the National Ocean and Atmospheric Administration’s Geophysical Fluid Dynamics Laboratory. His recent research found that more storms may make landfall in the U.S. as Category 4s and 5s by the end of this century. Even if we get fewer storms, they will be worse.

Trying to ride out storms of that size can be deadly. Overnight, Milton downgraded to a Category 4 but grew in size. It could also still reintensify to a Category 5. Florida is now preparing to evacuate potentially more than 6 million people ahead of Milton’s predicted landfall. And the conditions it will collide with on shore have already been worsened by climate change. The Gulf of Mexico has seen twice the global average rate of sea-level rise since 2010, according to an analysis by The Washington Post, and the sea along the Tampa Bay coast is now nearly five inches higher than it was 14 years ago. So when the storm surge floods the coast, salt water will probably travel farther inland, and likely with more force, than it would otherwise.

Milton also looks like a “very wet” storm, Gabriel A. Vecchi, a climate-science professor at Princeton University, told me, and Florida is already sopping wet. The state has been inundated with rain, and more will precede the storm. The ground is already saturated and so is unable to act as a sponge; ordinarily, it would serve as a partial buffer against flooding.

Rainfall is one of the best-understood areas of “attribution science,” the discipline that models how much worse climate change likely made any given weather scenario. And climate change is quite clearly making hurricane rainfall worse. Wehner and two colleagues at the Lawrence Berkeley National Laboratory put out a provisional analysis that found that, in some places in Georgia and the Carolinas, climate change may have caused as much as 50 percent more rainfall during Hurricane Helene. “Instead of 10 inches, they got 15 in some places. Instead of 20 inches, they got 30,” Wehner told me.

Only after Milton passes will scientists try to account for the ways that climate change made it more horrific than it might otherwise have been—perhaps still a major storm, but not so intense and so fast that it stopped a veteran meteorologist cold. And the world is expected to keep warming dramatically over the coming century; storms such as Milton are a preview of the types that will become more common, Vecchi told me. “We’re having a hard time dealing with storms this wet,” he said. “How are we going to do with storms that are wetter?” Surely those, too, will be shocking. But they should not be surprising: We’ll have known all along that they were coming.