As Hurricane Dorian barrels toward the Florida coast, it has been testing forecasters attempting to predict the precise path of what could be the most powerful hurricane to hit the state’s eastern shore in more than a quarter-century.
Dorian’s erratic behavior has been particularly hard to track. Adding to meteorologists’ woes are the many amateurs tracking the storm on their own and challenging the accuracy of expert forecasters.
Meteorologists have been surprised by the slow pace of Dorian, which swelled into a Category 4 storm on Friday night. It was inching toward the coast at 12 miles per hour, and forecasters revised their estimated arrival time, saying its center would approach the coast on Tuesday afternoon, though strong winds could begin thrashing Florida on Sunday.
On Saturday morning, the National Hurricane Center’s track for the hurricane moved northward, with forecasters indicating that the storm may drift along Florida’s coast — rather than running inland — and significantly weaken before hitting land in Georgia or South Carolina.
The jet streams that push hurricanes toward their destinations are relatively weak in this case, said Mike Brennan, who leads the Hurricane Specialist Unit at the National Hurricane Center in Miami. That means Hurricane Dorian may move more erratically, Mr. Brennan said, as it is more susceptible to the topography of the land it passes over and even thunderstorms in its berth, posing a challenge to forecasters hundreds of miles away.
With so little clarity, viewers armed with radar images, hurricane models and air pressure numbers are marching onto the Facebook and Twitter pages of forecasters’ stations and demanding more precise information, challenging their predictions and sometimes even accusing them of misleading the public.
Only a few years ago, residents might have not even known a storm existed until it was close to landfall, but now they are watching formations in the Atlantic Ocean and scouring the internet for raw storm data.
“It used to be, ‘Hey, I heard there’s a storm out there,’ and now it’s like, ‘What’s that cloud doing coming off of Africa?’” said Chris Smith, a meteorologist at the NBC affiliate in Panama City Beach, Fla.
Forecasters are working overtime to keep up with the intense demand for storm details, peeking at briefings while they feed their children breakfast and recording updates even when they are off the clock. They are dealing with probabilities but their viewers want precise answers to the same two questions: How bad will Hurricane Dorian be, and where will it head?
“It’s like being a witness in a trial,” Mr. Smith said. “You get the same questions a million different ways.”
Mr. Brennan added: “The limitations of the science run up against the demands of society.”
Some hobbyists have been following Dorian practically since it formed about 800 miles southeast of Barbados on Aug. 24, when it was a nameless tropical depression. In the absence of a surefire track for the storm, some amateur forecasters are sharing misleading information online, sometimes by posting an especially severe model as if it were a definitive prediction. The pros have a nickname for the posters: social mediarologist. And they can lead other viewers to then complain to local forecasters, many of whom see responding to their audience as part of their job description.
“Everyone can be a meteorologist nowadays, and I love that,” said Lauren Rautenkranz, a meteorologist at First Coast News in Jacksonville, Fla. “It’s just, we don’t want people to latch onto one specific computer model and think that’s a forecast. It’s guidance.”
Ms. Rautenkranz said she had emailed her colleagues this week to remind them to take a breath and not forget that 1,200 more models of the storm’s possible path would be generated before it reached the coast.
Sharon Coldren lives on St. John in the Virgin Islands and said she was more prepared than some other residents because she relied on a website of maps and satellite images in addition to the National Weather Service.
“We start to get a little suspicious, so we watch even more closely,” she said.
Hobbyists and forecasters often look at much of the same publicly available data from the National Hurricane Center and elsewhere. But forecasters have often spent years studying atmospheric science, learning what affects storms’ movements and how to distill hundreds of models into a reasonable prediction.
In recent days, expert forecasters like John Morales have turned to tools like Facebook Live to broadcast for longer periods of time, allowing them to share more thorough information. The hope is that viewers will understand why pinpointing a hurricane’s path can be almost impossible more than three days before it is predicted to run ashore.
In 1992, before Hurricane Andrew, Mr. Morales sat in front of a bulky television set in the studios of the local Univision affiliate and warned viewers to prepare for storm surge of up to 14 feet. His forecasts were fleeting, available to loyal fans only when the electricity and television were on.
Now, Mr. Morales spends every free minute forecasting Hurricane Dorian online. On television, he works only in the Miami media market. On social media, he serves a robust following in Florida, Puerto Rico and the Dominican Republic.
He especially likes the ability to speak in detail on Facebook Live, he said, often in a T-shirt from the comfort of his Miami home. When he started the broadcasts a few years ago, his wife would hold up a phone and his computer screen as he pointed at images. He has since upgraded to a desktop with a webcam, a large external microphone and software that allows him to draw on top of his models.
Constantly taking questions does not mean Mr. Morales’s followers like his answers.
“People are always seeking a deterministic, definitive answer,” he said during a rare break from his appearances as the chief meteorologist on Miami’s NBC News affiliate and on his online streams. “And generally speaking, the world meteorologists live in is one of probabilistic language.”
Mr. Morales has become something of a local celebrity meteorologist, a calming, reliable voice willing to field followers’ questions and offer lengthy explanations for the dreaded weather to come.
“Sometimes people see social media as a place where there might be disinformation or some say hostility or sarcasm. I see it differently,” he said. “I see it as a place where by answering one question, I can serve a thousand or thousands of people who have the very same question.”
Irene Sans, a digital meteorologist for the local ABC News affiliate in Orlando, said on-the-hour storm updates are no longer enough for audiences.
“People are not going to wait until 6 or 11,” she said. “Our job has become much more demanding.”
The criticism she faces is already fairly harsh, she said, when she predicts rain and viewers do not see a drop. But during a hurricane, it gets even worse.
She tries not to let it get to her.
“Yesterday I got a message saying, ‘This woman is so alarmist,’” she recalled. “I didn’t keep reading it. We’re talking about a Category 4 hurricane. If you want to call me alarmist, O.K.”
But most people, she said, appreciate up-to-the-minute updates, especially after the National Hurricane Center issues its regular advisories.
Mr. Smith, the meteorologist in Panama City Beach, said that while the amateurs can be frustrating, their vigilance is a reminder that forecasters need to meet their viewers’ needs.
“The only thing that changes on the weekend is I might not shave,” he said.