The early start to the 2020 Atlantic hurricane season — the sixth in a row and the first with three named storms by June 1— has rekindled calls to move up the season’s official start.
In a letter to the National Oceanic and Atmospheric Administration last week, U.S. Rep. Stephanie Murphy, an Orlando Democrat, asked the agency to reconsider the schedule, saying the June to November season no longer reflects hurricane activity.
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“This presents a practical problem, because government officials and residents in hurricane-prone states use this season to inform their funding choices, public awareness campaigns, and preparation decisions,” she wrote.
But hurricane experts, and the National Hurricane Center in particular, are wary of extending the season.
In an email, spokesman Christophar Vaccaro said the agency was looking forward to discussing the topic with Murphy.
Forecasters have long pointed to improvements in technology and the ability to detect smaller tropical systems as the reason for the rise in pre-season storms. Ship and buoy observations used during the early days of record-keeping that date back to the 1850s would have missed such storms, they say. And in recent years, a fleet of new satellites have dramatically increased data.
In 2016, NOAA and NASA launched an armada of eight small satellites along with a geostationary satellite, GOES East, capable of providing images four times stronger than previous satellite imagery.
“So we are more frequently identifying some of these weather systems in the tropics in May and April,” said David Nolan, a University of Miami hurricane researcher and professor at the Rosenstiel School of Marine and Atmospheric Science.
Hurricane forecasters have again called for an above average season for 2020, with 13 to 19 named storms, six to 10 hurricanes, and three to six major hurricanes with winds topping 111 mph.
But just because hurricane forecasters are now spotting these systems doesn’t mean the impacts have changed, he said. As in the past, most are small and pop up over water. When they do roll ashore, they tend not to pack the dangerous winds carried by systems that develop later in the season when conditions are more ripe, he said.
“They're not really any different than some regular weather system. Maybe a little bit more wind, but very limited impacts,” Nolan said. “Sometimes there can be significant flooding. But those parts of the forecast are usually handled by the local weather forecast offices.”
He also worries about hurricane fatigue from a longer season expected to produce more intense storms.
“I personally have always felt that the hurricane season started too early,” he said, noting that the majority of storms appear after July. “I would be concerned that if we started hurricane season, say, on May 15th or May 1st, then people would sort of forget. There would be a press conference and announcements and tweets and then people would actually forget.”
There’s also the toll it would take on forecasting staff, who spend the off-season updating forecast and storm surge models, creating new tools like drones being launched this year to measure lower levels of storms and doing outreach. For most teams working on these improvements, June 1 is a hard deadline to get that work done.
Once the season starts, the hurricane center also begins staffing the forecast office round-the-clock on most days, Nolan said.
“Overnight shifts are kind of a drag on anyone who’s done them,” he said.
Climate change is not expected to increase the frequency or duration of the season, although it is expected to fuel more intense storms. Last year, NOAA reported that the number of storms that underwent rapid intensification, with wind speeds jumping at least 35 mph winds in a day, had tripled between the 1980s and 2000s. But the same warming oceans that fuel hurricanes could also launch more El Nino events that produce upper atmospheric winds that tend to shred hurricanes.
Flooding is expected to worsen, but that's thanks largely to sea rise and increased rain. Over the last century, Florida and other parts of the southeast have seen about a 10 percent increase in rainfall, according to the Florida Climate Center at Florida State University. There’s also been an increase in storms that drop more than 2 inches of rain. But much of that rain — like the kind that flooded parts of South Florida over Memorial Day weekend — won’t need a tropical cyclone to produce it.
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