By Ali Sarhadi, Georgia Institute of Technology | –
(Communication) – Hurricane Milton went from hurricane strength to a Category 5 disaster in less than 24 hours as it crossed the Gulf of Mexico toward Florida.
As wind speeds increased, Milton became one of the fastest growing hurricanes on record. And with 180 mph sustained winds on October 7, 2024, and very low pressure, it also became one of the strongest storms of the year.
Less than two weeks after Hurricane Helene’s devastation, this type of storm was the last thing Florida wanted to see. Hurricane Milton was expected to make landfall as a major storm in late Oct. 9 or early Oct. 10 and it had already caused many people to move.
So, what exactly is increasing rapidly, and global climate change has to do with it? We research hurricane patterns and teach meteorology. Here’s what you need to know.
What is acceleration?
A strong storm is defined by the National Weather Service as an increase in wind gusts of up to 30 knots – about 35 mph within a 24-hour period. That increase could be enough to raise a hurricane from Category 1 to Category 3 on the Saffir-Simpson scale.
Milton’s wind speed went from 80 mph to 175 mph from 1 pm Sunday to 1 pm Monday, and its pressure dropped from 988 millibars to 911.
The National Hurricane Center has been warning that Milton could become a major hurricane, but this kind of rapid strengthening can catch people off guard, especially if it occurs near fall.
Hurricane Michael caused billions of dollars in damage in 2018 when it quickly intensified into a Category 5 storm before making landfall near Tyndall Air Force Base in the Florida Panhandle. In 2023, Hurricane Otis’ maximum wind speed increased by 100 mph in less than 24 hours before it hit Acapulco, Mexico. Hurricane Ian also intensified rapidly in 2022 before hitting south where Milton is expected to cross Florida.
What makes storms grow faster?
The rate of increase is difficult to predict, but there are a few driving forces.
- Ocean warming: Warming of the ocean’s surface temperature, especially when it penetrates deep areas of warm water, provides the energy needed for hurricanes to develop. The deeper the warm water, the more energy the storm absorbs, increasing its strength.
-
Low wind shear: Strong vertical wind shear – a rapid change in wind speed or a steep path – can disrupt the movement of air, while low wind shear allows storms to develop quickly. In Milton’s case, atmospheric conditions were the most likely to increase speed.
-
Moisture: Warmer sea surfaces and lower salinity increase the amount of moisture available to storms, increasing their speed. Warm water provides the heat needed to evaporate moisture, while low salinity helps trap that heat near the surface. This allows strong heat and moisture to flow to the storm, driving faster and stronger.
-
Thunderstorm activity: An internal force, such as an outbreak of strong thunderstorms within a tornado’s circulation, can reorganize the circulation of the tornado and lead to a rapid increase in strength, even if other conditions are unfavorable.
Research has found that around the world, the majority of hurricanes Category 3 and above tend to rapidly strengthen during their lifetime.
How does global warming affect hurricane strength?
If it seems like you’ve been hearing about the speed increase dramatically in recent years, that’s partly because it’s happening more often.
A 2023 study examining the relationship between rapid intensification and climate change found an increase in the number of tropical storms that are experiencing rapid growth over the past four decades. This includes a significant increase in the number of storms that rapidly increase in frequency during their development. Another study comparing trends from 1982 to 2017 with climate models found that natural variability alone cannot explain this increase in hurricanes, pointing to a possible effect of human-induced climate change.
How future climate change will affect hurricanes is an active area of ​​research. As global temperatures and oceans continue to warm, however, the frequency of major hurricanes is expected to increase. Extreme storms in recent years, including Beryl in June 2024 and Helene, are already raising alarms about the increasing warming of tropical cyclone patterns.
Zachary Handlos, Professor of Atmospheric Science, Georgia Institute of Technology and Ali Sarhadi, Assistant Professor of Atmospheric Science, Georgia Institute of Technology
This article is reprinted from The Conversation under a Creative Commons license. Read the first article.
#Climate #Change #Caused #CO2Causes #Hurricane #Milton #Explode #Category #Heads #Florida