Hurricane Idalia’s rapid intensification is becoming the norm for gulf storms
Hurricane Idalia, fueled by extremely warm ocean waters, rapidly intensified over the Gulf of Mexico into Tuesday night, exploding from a Category 1 storm with winds near 75 mph to a Category 4 storm with winds near 130 mph, before making landfall on Floridas Gulf Coast on Wednesday as a high-end Category 3. Idalia became one of 10 storms since 1950 to intensify by at least 40 mph in the 24 hours before U.S. landfall, joining a growing number of storms to have met the criteria for rapid intensification at least a 35 mph jump in 24 hours. Such storms are becoming more common, in part because of human-caused climate change. They are also more difficult to predict and often cause greater destruction, complicating emergency planning and response. In the Atlantic basin, which includes the Gulf of Mexico, 16 of the 20 hurricanes that formed during 2021 and 2022 rapidly intensified. Since 2017, seven rapidly intensifying storms have strengthened to at least a Category 4 (winds of at least 130 mph) before making landfall in the United States, together causing or contributing to at least 3,381 deaths and resulting in at least $496 billion in damage, according to reports compiled by the National Hurricane Center. Nearly 3,000 of the fatalities occurred in Puerto Rico after Hurricane Marias winds increased by 80 mph in one day before the storm devastated the island in September 2017. Scientists have identified climate change as one of the factors driving the upward trend in rapidly intensifying storms, whose sudden strengthening can be hard to predict. In September 2022, for example, Hurricane Ians wind speed increased from 115 mph to 161 mph the day before the storm ravaged southwest Florida, catching emergency managers and residents off-guard, especially near Fort Myers, where officials were criticized for how long they took to issue evacuation orders. A 2019 study led by meteorologist Kieran Bhatia found that a significant increase in rapidly intensifying hurricanes in the Atlantic Ocean since 1982 was made more likely by human-caused climate change. More recently, a global study led by Colorado State University hurricane researcher Philip Klotzbach did not find an increasing long-term trend in the number of storms intensifying by at least 35 mph in 24 hours. But when looking only at storms undergoing extreme rapid intensification a one-day wind increase of more than 57 mph the annual average climbed from less than 20 in the early 1990s to more than 30 in the past decade. Its hard to say how much of the increase in rapid intensification is due to human-caused climate change. But, Id say that it has likely contributed to the increase in these high-end rapid intensification events, Klotzbach said in an email. I think this makes sense given what we expect with climate change. That is, that climate change tends to shift the [extremes]. Record warm waters in the Gulf of Mexico helped Idalia rapidly intensify, especially as it entered a region with lighter winds in the upper levels of the atmosphere. Warm waters generally 80 degrees or higher are what fuel the development of tropical systems in the first place. The warmer the water, the more moisture that can be sucked up into the storm, allowing it to become stronger more quickly. And the weaker the upper-level winds, the more easily a storm can spin and strengthen. Water temperatures in the path of Idalia were in the upper 80s to near 90 degrees, the highest on record in the Gulf of Mexico, which has warmed underneath the same high-pressure heat dome that has scorched much of the southern United States for weeks. When Hurricane Laura traversed warm Gulf of Mexico waters in August 2020, the storm catapulted from a Category 1 storm with winds near 80 mph to a Category 4 storm with winds near 145 mph in 24 hours. Category 4 Ida, in 2022, was another Gulf of Mexico hurricane that underwent a leap in strength over anomalously warm gulf waters just before landfall in Louisiana. Before that, Michael surged to a Category 5 right before striking Floridas Panhandle in 2018; gulf waters were uncharacteristically warm then , too. This year, its not just the Gulf of Mexico thats warm. The Earths oceans are collectively the warmest theyve ever been , and theyve been steadily warming each decade since the 1950s. Climate change is one of multiple factors pushing ocean temperatures higher. Other factors that scientists have pointed to include changing wind patterns, reduced air pollution and El Nino. Climate change could also be helping storms rapidly intensify by slowing them down . The Earths poles are warming faster than the equator, which has reduced the temperature difference between them, possibly contributing to an observed slowdown in tropical systems near the United States. Slower storms have more time to gain strength from warm waters. Most storms that rapidly intensify become major hurricanes of Category 3 or higher. Such storms are the most dangerous because they typically produce the strongest winds, highest storm surge and the most rain. Storms that rapidly intensify before landfall have the highest intensity forecast errors and cause the majority of deaths and damage from tropical systems, according to research led by MIT hurricane expert Kerry Emanuel. A new study published last week came to a particularly concerning conclusion. The study found that while the annual number of tropical systems rapidly intensifying in the open ocean did not significantly increase between 1980 and 2020, the count tripled for those storms in offshore areas within 250 miles of a coastline, and thus the threat of rapid intensification in coastal regions may continue under a future warming climate. Because such tropical systems would likely make landfall within one day ... these regions represent an urgent concern for operational forecast owing to the relatively short amount of time for predictions and preparedness, the authors wrote. Research by Emanuel and others, including another study led by Bhatia, has shown that rapid intensification is likely to become more frequent in a warming world. However, variability across [ocean] basins and within basins make it difficult to say with high confidence how climate change will actually affect those future storms in specific places, meteorologist Matt Lanza wrote in a summary of recent research. Regardless of exactly where and when storms rapidly intensify, Bhatias study warns that forecasting tropical systems could grow even more challenging, given projections for a higher risk of rapidly intensifying storms in the future. Our conclusions indicate that [human-caused] climate change has already contributed to the observed, detectable increase in the proportion of rapidly intensifying hurricanes and highlight the immediate need to improve coastal resilience to prepare against these dangerous events, the authors wrote. An earlier version of this article misspelled Philip Klotzbach's last name. The article has been corrected. The latest: Idalia made landfall in Florida Wednesday morning as a Category 3 hurricane and has moved north through Georgia and toward the Carolinas. Its brought intense storm surge, flooding and damaging winds. Where is Idalia having the greatest impact? Heres our forecast for what to expect next in eight key cities . Path tracker: Were tracking Hurricane Idalia in maps as it moves across Florida. Storm surge: Waters are predicted to swell up to 15 feet in some spots, potentially causing flooding devastating flooding, the National Weather Service warns. Heres an explanation of what storm surge is . How to prepare: Our guide will show you how to keep your family and home safe before a hurricane hits, what to do if youre caught in the middle, and how to pick up when you return.