In August, the waters of the equatorial Pacific cooled, quieting powerful western gales that act as a balm to the tropical Atlantic during hurricane season.
The atmosphere took advantage of the lull, whipping quickly into a violent lather that crashed three Category 4 storms into the U.S., created the longest lived 185-mph hurricane in recorded history and drowned Houston in a tropical broth 5-feet deep.
The devastating 2017 hurricane season ends Nov. 30. Its formidable resume also includes the most named storms since 2012, more than double the normal number of major hurricanes, and an intensity and longevity cyclone score twice as fierce as the 30-year historical mean.
Hundreds of people in the U.S. and Caribbean died in storm-related incidents, although a final tally may not be known until the National Hurricane Center completes its storm reviews. Texas officials said in September that about 80 people were killed by Hurricane Harvey. In Florida, 72 people died from Hurricane Irma-related accidents, including five in Palm Beach County, according to the state’s Division of Emergency Management.
“It’s just one of those seasons where everything went supersonic,” said Chris Dolce, a digital meteorologist with Weather.com. “Everything that was out there, just wanted to develop. Every fledgling system decided to become a storm.”
It wasn’t just a La Niña-influenced atmosphere that created the hyperactive season, which began with Tropical Storm Arlene in April and wound down with Tropical Storm Rina on Nov. 7.
Abnormally warm sea-surface temperatures and a westward-sitting Bermuda High increased the fuel for the 17 named storms that formed, and pushed them closer to the U.S. as they rode the high’s underbelly as if on a conveyor belt.
Four hurricanes — Harvey, Irma, Maria and Nate — made landfall in the continental U.S. or Puerto Rico. Harvey, Irma and Maria were Category 4 giants at landfall.
Dan Brown, acting chief of the National Hurricane Center’s hurricane specialist unit, said the number of storms threatening land increased the pressure on forecasters this season.
“With a storm out over the open ocean, there may be ships in the way, but when storms are headed toward any highly populated area, we want to make sure people are getting the message and taking the actions they need to take so save their lives,” Brown said.
The first big challenge came with Hurricane Harvey. Born in the deep eastern Caribbean on Aug. 17, Harvey mustered only tropical storm strength before dissipating to a tropical depression and then reforming in the Gulf of Mexico.
The storm became a major Category 3 hurricane on Aug. 24 and rapidly intensified to a Category 4 before making landfall near Port O’Connor, Texas on Aug. 26. From there, it meandered, dropping more than 60 inches of rain and causing unprecedented flooding in the Houston area.
The National Weather Service tweeted; “This event is unprecedented and all impacts are unknown and beyond anything experienced.”
Still, Brown said Harvey was a well forecast storm with meteorologists predicting the track, rapid intensification and deluge of rain.
“Our track forecasts this year have set records for accuracy at each of the forecast time periods out five days,” Brown said. “The three most damaging hurricanes — Harvey, Irma and Maria — the track errors were 25 percent lower than the long term mean.”
Intensity was still a struggle, especially rapid intensification, which is considered an increase in wind speeds of 34 mph or more over a 24-hour period.
Brown said there were an estimated 40 cases of rapid intensification this season. Just six of them were accurately forecast.
Hurricane Maria’s 15-hour rapid intensification from a Category 1 storm to a Cat 5 was compared to 2005’s legendary Hurricane Wilma, which took just 12 hours to reach Cat 5 status.
Maria landed in Puerto Rico on Sept. 20, strafing the island with 155-mph winds. It wiped out Puerto Rico’s electrical grid, cut water lines and turned green hillsides brown from wind burn. As of Nov. 20 — two months after Maria made landfall — just 46 percent of the island had electricity.
“We had 10 hurricanes in a row and they were all sandwiched between early August and mid-October,” Dolce said. “It’s one of those years where you are just really taken aback.”
In between Harvey and Maria, was Irma, which formed Aug. 30 and quickly intensified to a Category 5 hurricane. It held that lofty status for an astonishing three days.
About 6.5 million Floridians evacuated for the storm — the most in the state’s history.
“This was a big, nasty Category 5 hurricane and it got people’s attention,” said Jason Senkbeil, a University of Alabama associate professor who interviewed evacuees at a service plaza on Sept. 7 and 8. “Some people thought all of Florida was going to experience Cat 4 or 5 winds.”
Irma’s fury was reduced somewhat by a rub against Cuba’s northern coast. It made landfall as a Category 4 storm near Florida’s Cudjoe Key on Sept. 10 at 9:10 a.m.
“This season definitely put things in perspective,” said Jonathan Rizzo, the warning coordination meteorologist for the National Weather Service in Key West. “The fact that Irma remained a Cat 5 for so long, even among intense hurricanes, it’s not something you normally see.”
Rizzo, who lives in Key West, said the weight of Irma’s potential impact hit him on Sept. 4 — Labor Day. The five-day forecast cone was inching closer and almost every possible path had some sort of impact on the Keys.
He sent his family to Orlando two days later.
Rizzo was stationed at the Marathon emergency operations center, which had to relocate to Ocean Reef when there were concerns it wouldn’t hold up to Irma’s blow. During the storm he was so focused on forecasting, he didn’t have time to worry about his home.
“The reason we stay is to make sure that our emergency managers and the public gets the critical information they need,” said Rizzo, whose home weathered the storm. “I know I sound nonchalant, but after 2005 and seeing Wilma’s impacts, you start to realize that you can survive this. We’re not victims, we are survivors.”
Statewide, 90 percent of Florida Power and Light customers lost electricity with the average outage lasting 2.3 days. That’s compared to 75 percent of customers who lost electricity during Wilma when the average outage was 5.4 days.
In Palm Beach County, more than 290,000 people were urged to evacuate coastal areas and from around Lake Okeechobee. About 17,000 stayed in shelters.
But while Irma knocked over trees with gusts that reached 91 mph at Palm Beach International Airport, homes were largely spared.
“We got lucky. We got very lucky, again,” said Bill Johnson, head of Palm Beach County’s emergency management division. “But some day our luck is going to run out.”
2017 hurricane season stats:
- 17 named storms, including 10 hurricanes and six major hurricanes
- Major hurricanes spun for 19.25 days — the most since 2005
- Harvey was first major hurricane to make landfall in continental U.S. since 2005’s Wilma
- Harvey produced more than 60 inches of rain, breaking previous rainfall record of 52 inches
- Irma’s maximum wind speed of 185 mph was strongest on record in Atlantic, outside Gulf of Mexico and Caribbean
- Irma maintained 185-mph winds for 37 hours - the longest any tropical cyclone around the globe has maintained that intensity
- Irma was the first Category 4 hurricane to make landfall in Florida since 2004’s Charley
- Irma and Harvey marked the first time two Category 4 hurricanes made landfall in the continental U.S. in same year
- Irma spent three days as a Category 5 hurricane — the longest for an Atlantic hurricane in the satellite era (since 1966).
(Source: Colorado State University Department of Atmospheric Science)
2017 tropical cyclones and maximum sustained winds:
Tropical Storm Arlene, 50 mph
Tropical Storm Bret, 45 mph
Tropical Storm Cindy, 60 mph
Tropical Storm Don, 50 mph
Tropical Storm Emily, 45 mph
Hurricane Franklin, 85 mph
Hurricane Gert, 105 mph
Major Hurricane Harvey, 130 mph
Major Hurricane Irma, 185 mph
Major Hurricane Jose, 155 mph
Hurricane Katia, 105 mph
Major Hurricane Lee, 115 mph
Major Hurricane Maria, 175 mph
Hurricane Nate, 90
Major Hurricane Ophelia, 115 mph
Tropical Storm Philippe, 60 mph
* Major hurricane is a Category 3 or higher
(Source: National Hurricane Center)