Millions more US homes are at risk of flooding than previously known, new analysis shows. While there isn't much definitive data on rapid intensification, a few key atmospheric ingredients help it happen, CNN meteorologist Michael Guy said. They're the same conditions that often emerge in the Atlantic basin between August and October. Ocean water needs to be warm -- more than 86 degrees Fahrenheit is ideal -- with that heat extending beneath the surface.
Upper level winds must be calm so they don't disrupt thunderstorm activity. A storm's internal conditions also must be just right.
A hurricane needs a way to ventilate, much like a car engine, so it can continue to process all of the fuel from the warm water and use it to strengthen the storm. Rapid intensification is rare. Because all those pieces must be in place, rapid intensification is rare, with just one or two Atlantic storms per year undergoing such an acceleration.
That said, most storms that reach the highest categories -- 3, 4 and 5 -- reach these intensities through rapid intensification. In , Hurricane Patricia, one of the strongest storms ever recorded, went through one of the fastest and most drastic rapid intensification cycles, with winds increasing about mph in 24 hours. These storms are more dangerous. Storms that undergo rapid intensification tend to be more dangerous than other storms because they frequently end up as major hurricanes.
Adding to the problem, the speed at which they strengthen allows for less warning time. This happened to those on the island of Dominica ahead of Hurricane Maria in But it's notoriously hard to predict rapid intensification because forecast models fail to pick up on all the different variables that feed into it -- and because rapid intensification doesn't always happen when the variables are present.
For instance, forecast models did not predict the rapid intensification in that made Hurricane Harvey a Category 4 storm in such a short period before it hit the Texas coast.
Storms are rapidly intensifying more frequently. Satellites can only measure surface ocean temperatures. Approaches to obtaining these data include autonomous ocean gliders that swim beneath the ocean surface, measuring temperature, salinity and other characteristics.
And satellites that can measure the height of the sea surface can be helpful because a warmer body of water takes up more room. We humans have been using the atmosphere as a dumpster for more than 50 years now.
And we have known for a very long time that these gases trap heat that largely goes into the ocean, thereby fueling these storms and also warming up the atmosphere.
And the way to go about that is to stop emitting these heat-trapping gases. We know that solar and wind and other renewables can totally replace our electricity. We just need to get on with it faster. We can make a lot of choices in our own lives, in our own communities and at the state level, such as incentives to support buying a car that's more efficient, to buy appliances that are more efficient or to insulate your home better. We have to pull out all the stops.
We also have to get ready. Our actions now will affect how [future] warming occurs. We are going to see more extremes; we are going to see more rapidly intensifying storms; we are going to see more heat waves and more fires. So we need to prepare for those. When a home gets flooded out for the third time in a decade, does it make sense to spend tax dollars to help that person rebuild that home in the same spot?
It does not. Already a subscriber? Sign in. Thanks for reading Scientific American. High wind shear will disrupt the clouds, making it hard for the storm to stay together. When all of these ingredients are present, vigorous thunderstorms can form and organize, allowing a robust eyewall to develop.
Because these ingredients change, the Atlantic hurricane season varies year to year. This year, as the seasonal forecasts created by Colorado State University and the National Oceanic and Atmospheric Administration warned, the ingredients are favorable for an active season with more major hurricanes. We saw that with Hurricane Marco. It swept through the Gulf of Mexico just ahead of Hurricane Laura but weakened to a tropical storm before landfall.
A big difference was the wind shear. When then-Tropical Storm Laura passed over Cuba into the Gulf, the high wind shear conditions had receded, leaving nothing but a favorable environment for Laura to develop catastrophic winds and a dangerous storm surge. We have seen more rapid intensification events in recent years, and some scientists have concluded that the warming climate is likely playing a role.
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