The 2019 Atlantic hurricane season, the fourth in a row with above-average activity, was one we won’t soon forget. It will be remembered most for Dorian, which razed the northwest Bahamas as one of the most intense hurricanes observed in the Atlantic.
Both Dorian and Lorenzo, which became the strongest hurricane to develop so far northeast in the Atlantic, attained Category 5 strength. The storms brought the count of Category 5s in the Atlantic since 2016 up to six, and marked the fourth year in a row with at least one Category 5, the longest stretch on record.
The historic intensity of both Dorian and Lorenzo, along with the record-setting rains produced by storms Barry and Imelda in the United States, exhibited influences consistent with warming ocean waters and climate change.
Yet for many stateside, 2019 may have seemed tame since the most violent hurricane conditions remained offshore, unlike in 2017 and 2018.
We break down how deceptively destructive the season was, which ended Saturday, and how it stacks up against previous years.
The 2019 Atlantic hurricane season at a glance
This year had an above-average season. It was only the seventh season since the 1930s to rack up multiple Category 5s over the Atlantic Basin. Across the board, 24 percent more “accumulated cyclone energy” than average was expended by storms this season. It also brought about one of the strongest Atlantic hurricane landfalls on record.
But many in the United States view the season as a reprieve for the storm-beleaguered country, noting that only two hurricanes made landfall in the United States this season, along with one tropical storm. Both hurricanes were at Category 1 strength when they did so. The year was still incredibly active; the contiguous United States just got lucky.
During just the 2016, 2017 and 2018 hurricane seasons, the United States was hit by six tropical storms and eight hurricanes — including three Category 4s (Harvey, Irma and Maria) and Michael, the first Category 5 U.S. landfall since Andrew in 1992. Considering how things panned out in the United States this season, it’s easy to write this off as a lucky break. But for tens of thousands of people just 100 miles northeast of Miami in the northwest Bahamas, that couldn’t be further from the truth.
U.S. storm impacts
Just because the United States “only” dealt with two Category 1 hurricanes and a tropical storm this year, it doesn’t mean the nation didn’t experience some very damaging storms.
Take Imelda, for example. On Sept. 17, a system off the Texas and Louisiana Gulf coasts began to show signs of organization. It was labeled a tropical depression by lunchtime. Forty-five minutes later, it was declared Tropical Storm Imelda. Another 45 minutes after that, the storm made landfall with 40 mph winds.
But winds account for less than an eighth of all tropical-cyclone-related fatalities. Nearly 60 percent of cyclone deaths come from inland freshwater flooding. That was the sneaky killer that had been a concern days before Imelda’s arrival.
Enduring rainfall rates of five inches per hour at times, communities in Texas’s Golden Triangle such as Beaumont and Port Arthur watched as flooding reminiscent of Hurricane Harvey in 2017 engulfed their homes and businesses.
In Jefferson County, 43.15 inches fell, making Imelda the fifth-wettest landfalling tropical cyclone on record to impact the Lower 48. As warming oceans are expected to increase rainfall from tropical weather systems, one analysis concluded climate change doubled the odds of a deluge so extreme in this area.
The storm was ultimately blamed for at least five fatalities.
Months earlier, the United States also dealt with Hurricane Barry. It formed on July 11 and made landfall in Louisiana on the 13th as a minimal Category 1 hurricane. It only had a tiny area of 75 mph winds; heavy rainfall was the main threat.
When all was said and done, Ragley, La., wound up with 23.43 inches, while Barry’s remnants brought 16.59 inches inland near Dierks, Ark. That claimed the state tropical cyclone record, the fifth such U.S. record to fall in the past three years.
The only other cyclone to impact the United States was Dorian. It brought tropical-storm force winds to much of the southeast coast, along with tornadoes to the Carolinas. The storm also triggered a flash flood emergency for Ocracoke along the North Carolina Outer Banks on Sept. 6 as water levels spiked seven feet in two hours because of Dorian’s surge.
Dorian’s remnants may have whipped up a 100-foot ocean wave near Newfoundland days later.
Dorian will also be recalled for instigating political controversy when President Trump inaccurately tweeted that the storm posed a threat to Alabama and then, through his chief of staff and Commerce Secretary Wilbur Ross, pressured the National Oceanic and Atmospheric Administration to side with him rather than National Weather Service forecasters, who correctly said the state was not at risk.
Dorian in the Bahamas
Dorian coincided with the peak of the hurricane season, its sustained 185 mph assault on Great Abaco Island tying the 1935 Labor Day storm as the most intense Atlantic hurricane landfall on record by wind speed. Sixty-nine fatalities have been confirmed due to the storm.
Tropical Storm Dorian was named on the afternoon of Aug. 24. Puerto Rico was placed under a tropical storm watch two days later, with Dorian making a close pass to the east on Aug. 28. Winds gusted to 111 mph on Buck Island south of St. Thomas, prompting the reclassification of Dorian as a hurricane.
On Sunday, Sept. 1, Dorian slammed into Great Abaco with sustained winds of 185 mph and gusts topping 200 mph. The National Hurricane Center called it “catastrophic” and predicted that a surge of water 18 to 23 feet above normally dry land would engulf the coast. Homes were plunged below water as howling, tornado-like winds screamed for hours. And it didn’t stop.
Dorian finally wobbled over to Grand Bahama, where its eyewall, the hurricane’s zone of most destructive winds, scoured the island for 40 hours straight. Moving at just 1.3 miles per hour — less than walking pace — Dorian was the slowest-moving Category 5 on record. Parts of the island may have endured the longest siege of violent weather observed.
Pelican Point on Grand Bahama island appeared to have been battered by the extreme eyewall winds of 120 mph or more for over 25 consecutive hours. After that, it was thrust into the eerily calm eye for eight hours.
Initial forecasts indicated Dorian would deal a devastating blow to Miami and the Florida Peninsula, but refined data thereafter correctly modeled Dorian to stay offshore.
“Many millions of well-prepared people were nervously watching it on radar and satellite for days,” wrote Brian McNoldy, CWG’s tropical weather expert. Then “it began a slow northward drift toward the Carolinas. For the southeast U.S. coast from south Florida to the Outer Banks of North Carolina, early September was not easy, just lucky.”
Lorenzo was bizarre, a meteorological freak show of errant power and disconcerting beauty.
Lorenzo briefly peaked as a Category 5 hurricane on the night of Sept. 28, far out in the middle of the Atlantic Ocean. It reached this elusive tier of strength some 600 miles east-northeast of the previous farthest-east Category 5 storms in the Atlantic, while its estimated air pressure of 925 millibars made it the lowest air pressure on record for the Atlantic east of 50 degrees west longitude.
It was also only the 10th major hurricane on record east of the 40 degrees west marker. Five of those have occurred in the past decade, a number that National Hurricane Center forecaster Eric Blake called “probably no coincidence.”
Though Lorenzo didn’t bother anybody as a major hurricane out at sea, it may bear the telltale fingerprint of our rapidly warming climate.
Hurricanes are the atmospheric equivalent of large heat engines; given that there’s more thermal heat input by the ocean as seas continue to warm, scientists have concluded that more of these higher-end storms are likely in the future and perhaps in more unusual areas. The waters at the time of Lorenzo’s explosive intensification were several degrees warmer than normal.
A summary of available research from NOAA’s Geophysical Fluid Dynamics Laboratory notes that “tropical cyclone intensities globally will likely increase.” An increase in the most intense tropical cyclones, Category 4s and 5s, may already be underway. Each of the past four Atlantic hurricane seasons has featured at least one Category 5.
But it’s advisable not to put too much stock into Lorenzo’s brief blip as a Category 5. “Before the geostationary satellite era, there’s no way we would have caught a storm in the eastern Atlantic that blinked into the [Category 5] realm for a few hours, at best,” McNoldy wrote.
One interesting element of the 2019 hurricane season is that eight of the 18 named storms were around for only two days or less, McNoldy said: “Short-lived storms can sneak into any season and crank up the storm count.”
The season featured four storms that were dubbed “subtropical” — not quite tropical cyclones, but with characteristics more tropical in nature than typical extratropical cyclones.
Subtropical storms are often smaller than full-fledged tropical storms or hurricanes; the advent of modern satellite technology has contributed enormously to their detection and forecasting. Beforehand, we likely didn’t keep tabs on them quite as well. That’s why McNoldy advises that “using [total number of] named storms as a metric for evaluating climate change would be a bad idea.”
Finally done, most likely
Barring any surprises, the 2019 Atlantic hurricane season is finally over. Historically, tropical storms have spun up in the Atlantic during every month of the year, with hurricanes forming in all but February and April. Among them was a Category 2 storm that brought 100 mph winds to the U.S. Virgin Islands during March 1908.
Jason Samenow contributed to this report.