Hurricane Melissa Could Drop Two Feet of Rain on Jamaica

Almost Hurricane Melissa will dump stunning rain on Jamaica

TO Megan Bartels edited by Andrea Thompson

Tropical Storm Melissa is poised to devastate Jamaica and parts of Haiti this weekend as a slow-moving storm quickly develops into a powerful storm. hurricane and dumps huge amounts of rain on the Caribbean islands. Some areas received up to 20 inches of rain in just a few days. At this depth, the volume of water in an Olympic swimming pool is unlikely to be less than the area of ​​a football field.

Winds are the threat most associated with hurricanes, followed by storm surges. But rain is an often overlooked hazard from these storms, and it can be the most dangerous. That was the case with Hurricane Harvey in 2017, which set the rainfall record for a single storm in the continental U.S. when it dropped more than 48 inches of rain near Houston, and with last year's Hurricane Helen, which dumped two feet of rain in the Appalachians just days after a previous rainfall of about one foot in the region.

READ MORE: There's a lot of jargon in hurricane science: here's what it all means

About supporting science journalism

If you enjoyed this article, please consider supporting our award-winning journalism. subscription. By purchasing a subscription, you help ensure a future of influential stories about the discoveries and ideas shaping our world today.

As of midday Oct. 23, Melissa is a tropical storm with peak sustained winds of 45 mph, operating despite the ongoing three-week federal government shutdown, according to the National Oceanic and Atmospheric Administration's National Hurricane Center. The storm is expected to strengthen into a hurricane within 48 hours and strengthen into a major Category 3 hurricane by Sunday, before possibly becoming a Category 4 hurricane by Monday. (Forecasters are still watching to see whether Melissa could threaten the continental U.S. next week.)

But while Melissa's winds are forecast to develop into powerful gusts, the atmosphere around the storm is calm and the potential hurricane will meander across the Caribbean Sea. Melissa's eye is currently moving at only two miles per hour. “You or I could go faster than it's moving,” says Brian McNoldy, a hurricane researcher at the University of Miami. All severe hurricane threats worsen when the storm moves slowly, since any given location is exposed to hurricanes for a long time. “Being hit by a hurricane is never a good thing,” McNoldy says. “But getting hit by a hurricane that isn’t moving is much worse.”

As Melissa crawls past, she drops a massive amount of rain on the islands in her path. Western Jamaica is currently forecast to receive nearly a foot of rain over the next three days, with some locations exceeding that, according to the National Hurricane Center. But the storm's timeline is currently longer than predicted; Former NOAA meteorologist Alan Gerard expects parts of the Caribbean to receive at least 20 inches of rain from Melissa.

More intense precipitation from storms of all kinds is becoming increasingly likely as warming conditions cause the atmosphere to hold more water vapor. “It's an imprint of how climate change is affecting storms—in general, more moisture, more rain,” McNoldy says.

He worries that Melissa's devastation in the Caribbean will be exacerbated by the mountainous terrain of islands such as Jamaica and Hispaniola, divided between Haiti and the Dominican Republic. This landscape is especially vulnerable to flash floods and landslides as water rushes to the lowest elevation it can find. terrible flooding, Hurricane Helen brought Appalachia last fall. Additionally, mountainous landscapes themselves can aggravate precipitation because when an air mass hits a mountainside, it is pushed upward, causing more water to be dumped into it, McNoldy says.

This combination can be a recipe for terrible events. flash floodwhich is especially dangerous on steep slopes that cause huge amounts of water to flow into small areas. “When you get even half a foot of rain, it’s just a ridiculous amount of rain,” McNoldy said. “When you get more than 12 inches of rain, that's too much for any place, no matter how good your infrastructure is.”

It's time to stand up for science

If you liked this article, I would like to ask for your support. Scientific American has been a champion of science and industry for 180 years, and now may be the most critical moment in that two-century history.

I was Scientific American I have been a subscriber since I was 12, and it has helped shape my view of the world. science always educates and delights me, instills a sense of awe in front of our vast and beautiful universe. I hope it does the same for you.

If you subscribe to Scientific Americanyou help ensure our coverage focuses on meaningful research and discovery; that we have the resources to report on decisions that threaten laboratories across the US; and that we support both aspiring and working scientists at a time when the value of science itself too often goes unrecognized.

In return you receive important news, fascinating podcastsbrilliant infographics, newsletters you can't missvideos worth watching challenging gamesand the world's best scientific articles and reporting. You can even give someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you will support us in this mission.