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Hurricane Irma, one of the most powerful storms ever measured, is slamming the Caribbean — and Florida is now in the crosshairs
(National Hurricane Center)
Hurricane Irma has slammed into several Caribbean islands as a "potentially catastrophic" Category 5 storm.
The National Hurricane Center's projected path shows Irma arriving in South Florida over the weekend or traveling up the state's east coast.
Gov. Rick Scott of Florida has activated the state's National Guard, and the Florida Keys and parts of South Florida have ordered mandatory evacuations.
President Donald Trump has declared a state of emergency for Florida in anticipation of the storm.
A week after Hurricane Harvey made landfall, devastating Texas with torrential flooding, Hurricane Irma has begun steamrolling several Caribbean islands.
The initial damage of Irma, one of the most powerful Atlantic hurricanes in recorded history, was observed on Wednesday in Barbuda, an island east of Puerto Rico. The Associated Press reports that fierce winds there lifted off the roof of a police station, prompting officers to take shelter in a nearby fire station. Communication with the island was cut off because of the destruction.
According to the AP, Antigua and Barbuda told residents to seek shelter from Irma's "onslaught" in a statement that closed with: "May God protect us all."
The National Hurricane Center's latest forecast for Irma projects that the centerline of the Category 5 storm could go right over Miami before heading up the east coast of Florida. However, the storm is big and powerful enough to affect most of the state, even if it stays offshore.
"Even if Irma does take this trajectory passing directly over the eastern coast, we certainly would expect it to impact the whole state," James Belanger, a senior meteorological scientist with The Weather Company, the group behind the Weather Channel and Weather Underground, told Business Insider on Wednesday.
Though it's too soon to say for certain where the storm will go, the forecast strongly suggests Irma will hit South Florida as a major hurricane on Sunday. As a result, US and state officials are now urging people to ready their emergency plans and supplies.
"We do not know the exact path of this storm, but weather can change in an instant, and while we hope for the best, we must prepare for the worst," Gov. Rick Scott of Florida said in a Tuesday statement.
(Ligia Marquez loads water in the Little Havana neighborhood of Miami on Tuesday.REUTERS/Joe Skipper)
Irma's intensity
Irma formed off the coast of western Africa last week and almost immediately started crossing the Caribbean Sea. Phil Klotzbach, a meteorologist at Colorado State University specializing in Atlantic hurricanes, told Business Insider last week that a combination of conditions — including a warm tropical Atlantic, a weak wind shear, and a change from drier to wetter weather — made it easy for Irma to pick up strength.
Irma officially became a named storm on August 30 and was classified as a hurricane the next day. Since then, it has gained and maintained strength from the moisture of unusually warm waters in the Atlantic Ocean and the Caribbean Sea.
The Category 5 label means Irma has sustained winds of at least 157 mph near its core. The latest "hurricane hunter" airplane measurements suggest the storm's sustained winds now top 185 mph, though gusts have been recorded in excess of 215 mph. That makes Irma the strongest hurricane ever measured in the Atlantic Ocean, outside of the Caribbean Sea or the Gulf of Mexico, where Hurricane Allen still holds the record. Some recent flights have found that Irma is still intensifying.
(The GOES-16 satellite's view on Tuesday of Hurricane Irma as a Category 5 storm.CIRA/RAMMB; NOAA)
The storm's winds are as powerful as those in a severe tornado, which can tear off roofs, level homes, toss cars, overturn trains, and uproot large trees.
Irma also threatens the Caribbean and US with storm surge, a crest of water formed ahead of a storm by powerful winds. The NHC suggests that the Bahamas, for example, may see a storm surge with a height of 20 feet above a typical high tide, though forecasts differ greatly among regions.
"Some fluctuations in intensity are likely during the next day or two, but Irma is forecast to remain a powerful Category 4 or 5 hurricane during the next couple of days," the NHC said in a public advisory on Wednesday. It also called Irma a "potentially catastrophic" hurricane and advised that preparations "should be rushed to completion" in all hurricane warning areas.
That main forecast is that Irma will remain a Category 5 hurricane until Saturday, then become a Category 4 storm.
"But one of the things we need to keep in mind is that some of the guidance is that the storm is going to maintain [strength]," Belanger said, adding that "it's possible the storm could strengthen further" as it passes over warm waters on the way to the Bahamas.
Warning areas include the Virgin Islands, Puerto Rico, and parts of the Dominican Republic, where the storm is expected to arrive shortly, according to forecasts. The southern Bahamas are in the path for a direct hit on Thursday.
Possible landfall in the US
Forecasters don't yet know whether Irma will make landfall in the US, let alone as such a powerful storm. But the latest computer models are not comforting.
Two of the most predictive models show that South Florida and Miami may be in Irma's path. If this scenario plays out, tropical-storm-force winds could reach the Florida Peninsula as soon as Saturday.
Though most forecasts have Irma traveling up the east coast of Florida or hitting the southern part of the state, the storm's path is still uncertain this far out, according to Belanger.
Irma "could impact Georgia and South Carolina, but it could even make its way into the Western Gulf," he said, though that's not the most likely track. "It's important that people monitor the official forecast."
To prepare for Irma, Scott ordered all 7,000 members of Florida's National Guard to report for duty on Friday morning. Miami-Dade County is also evacuating some of the lowest-lying areas prone to storm surge, including Miami Beach.
The Florida Keys, meanwhile, are closing schools and issued a mandatory evacuation order for all visitors and residents starting Wednesday morning.
President Donald Trump declared states of emergency in Florida, Puerto Rico, and the US Virgin Islands on Tuesday evening to free up federal resources for a major response to the storm.
If you live in S Florida, this is all you need to take #Irma very seriously.
Remarkable agreement between GFS & Euro, our two best models. pic.twitter.com/kMQiQNAQ16— Eric Holthaus (@EricHolthaus) September 5, 2017
A busy hurricane season
Irma has already put the Atlantic far ahead of the average accumulated cyclone energy — a measure of the energy of tropical cyclone systems — for this time of year.
Both Colorado State University and The Weather Company predicted an unusually active hurricane season this year. Irma is already the fourth hurricane of 2017, though the average date of the fourth hurricane in a year is September 21. The peak of the season is around September 10.
Klotzbach said that half of a season's cyclone energy usually occurs in September, meaning major hurricanes are likely still to come. Tropical Storm Jose, which is east of Irma, is expected to reach hurricane strength on Wednesday afternoon, and could also make its way toward the Caribbean. Another tropical storm, Katia, is located off the coast of Mexico.
Big hurricanes are usually defined by their wind force, but as seen with Harvey, which made landfall as a Category 4 hurricane but caused most of its damage with heavy rain, the number doesn't always accurately predict a storm's impact. And there's no category above 5, making it hard to differentiate among even more severe storms. Here's what the scale means:
(Ana Pelisson/Business Insider)
This is a developing story. Find all of Business Insider's latest Hurricane Irma coverage here.
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