Weather News

Seems like Dorian just won’t end? See how it compares to other long-running storms

Hurricane Irma — one of the strongest hurricanes on record in the Atlantic Ocean — lasted a total of 13 days, according to the National Hurricane Center.

Dorian officially tied it as one of the longest running storms on Friday.

NHC named Dorian as a tropical storm on Aug. 24 as it garnered strength far off the coast of South America. On Friday, the eye finally made landfall over Cape Hatteras, North Carolina.

In the 13 intervening days, Dorian matched various records held by some of the Atlantic’s most notorious storms. But some are wondering: how long will it last?

Dorian’s longevity

It can take anywhere from one day to a full month for hurricanes to run their course, according to AccuWeather.

At 13 days, Dorian tied 2017’s Hurricane Irma and two other storms on Friday morning for most “named storm days” by a hurricane in the Atlantic since 1966, according to Colorado State University meteorologist Philip Klotzbach.

“The record for Atlantic August named storm longevity is Hurricane Alberto in 2000, which was a named storm for 19.25 days,” he said on Twitter.

Dorian’s named days will continue to climb as it moves north over the next couple days, Ben Trabing, a PhD candidate working with Dr. Klotzbach at CSU, told McClatchy news group in an email.

Dorian’s path

Dorian lumbered into South Carolina late Wednesday, waffling in strength throughout its slow trek that fell to just 1 mph at times, according to the NHC.

It returned to Category 1 strength by the time the eye made landfall Friday morning and should clear the coast by nightfall. Traveling north at 21 mph, Dorian was already more than 100 miles away from where it made a direct hit off the coast of North Carolina.

The NHC also issued hurricane watches and warnings for parts of Canada, which Dorian is expected to clear Sunday.

Contributing factors

Dorian tracked the second shortest straight-line distance by a major hurricane in the Atlantic since 1950 when it moved only 25 miles in 24 hours, according to a fact sheet released by Colorado State University.

The last storm to travel slower than that was Hurricane Betsy in 1956, which moved 12 miles in 24 hours.

Speed is typically determined by surrounding weather systems, Trabing said.

“You can imagine a hurricane like a leaf floating on a stream,” he said. “If the stream is moving fast, then the leaf will follow the stream. But if the stream widens and slows down — or the leaf enters a nook along the edge of the stream — the leaf will slow down or stop entirely.”

Dorian also didn’t touch a major land mass, avoiding Cuba, Puerto Rico and Florida on its trek toward the Carolinas.

“Small flat islands typically do not have a large effect on the intensity of a hurricane, but islands with mountains like Cuba and Puerto Rico do,” he said.

Without landfall to weaken its energy supply, Dorian was able to keep its strength. Trabing said “more adverse conditions” were needed to downgrade it to a tropical storm once Dorian became a major hurricane.

“Imagine Dorian as a giant spinning top. If it (is) spinning really fast, you can touch the top and it may wobble or move but it will still be spinning upright,” he said. “Making landfall is the fastest way to weaken a hurricane.”

Other records

Klotzbach also said Dorian tied Hurricanes Florence (2018) and Floyd (1999) for sixth place in minimum sea pressure for landfalling North Carolina hurricanes since 1950. Lower sea pressure indicates a stronger storm.

The only other recent hurricane ranked ahead of them is Irene in 2011.

Dorian “tied for the second strongest Atlantic hurricane by wind speed” at 185 mph, according to AccuWeather.

Those speeds had dropped below 70 mph Friday afternoon, the NHC said.

It was also strongest by pressure to make landfall in the Bahamas, according to a fact sheet released by Colorado State University.

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Hayley is a Real Time reporter at The Charlotte Observer covering breaking news and trending stories in the Carolinas. She also created the Observer’s unofficial bird beat (est. 2015) with a summer full of ornithological-related content, including a story about Barred Owls in love.