Hurricane forecasters expect Tropical Storm Debby to form, drench Florida
Editor's note: Follow the latest news about this developing storm in our Saturday coverage, including the latest maps and models
Tropical storm watches and warnings were hoisted Friday for the west coast of Florida as a developing system threatens to drench much of the state with heavy rain over the weekend.
The main impact from the storm – which would be named Tropical Storm Debby – will likely be heavy rainfall, with up to a foot possible in some areas. That "may result in flash and urban flooding across portions of Florida and the Southeast this weekend through Wednesday morning," the National Hurricane Center said Friday. Isolated river flooding will also be possible.
Other impacts include tropical-storm-force winds and a 1-3 foot storm surge in some areas, the NHC warned Friday.
What is the forecast for Potential Tropical Cyclone Four?
The tropical wave in question, which the NHC has dubbed Potential Tropical Cyclone Four, moved across Cuba on Friday and will emerge over the Straits of Florida (the J-shaped channel located between the Florida Keys and Cuba) on Friday night or Saturday, the NHC said Friday.
It will become a tropical depression overnight tonight, then Tropical Storm Debby on Saturday, the NHC said. A system transitions from a depression to a named tropical storm when its sustained winds reach 39 mph. If winds reach 74 mph, it becomes a hurricane.
"Keep in mind the tropical cyclone will be strengthening as it moves north, so the farther north it gets before landfall, the better of a shot that it has to attain hurricane status," said the National Weather Service in Tallahassee, Florida, on Friday.
At some point, the storm will move inland and reemerge along the Atlantic Seaboard to begin a slow crawl along the Georgia and Carolina coastlines early next week.
The National Oceanic and Atmospheric Administration's Hurricane Hunter aircraft is scheduled to investigate this system later Friday, the agency said.
Where is Potential Tropical Cyclone Four?
Location: 25 miles west of Camaguey, Cuba; 315 miles southeast of Key West
Maximum sustained winds: 30 mph
Movement: west-northwest at 16 mph
State of emergency in Florida
Florida Gov. Ron DeSantis declared a state of emergency for 54 of the state's 67 counties in anticipation of what could be the first major storm of the hurricane season in the region, with the potential to cause weekslong river flooding, the Pensacola News Journal reported.
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In a post on X Thursday afternoon, DeSantis said "Florida is monitoring Invest 97L in the Atlantic, which is expected to strengthen and potentially make landfall as early as this weekend. It will be slow-moving and bring lots of rain that could cause significant flooding. I encourage all residents to prepare for the storm and follow all guidance issued by @FLSERT and local emergency management officials."
Key West is ready
Key West Mayor Teri Johnston said her tiny island community was "well prepared but not worried" about the storm.
"Everyone's on it, everyone knows what to do. Load up on 3-to-7 days of supplies and water, batteries, remove all potential projectiles from the yard," she said Friday. "We're ready."
A tornado or two is possible across the Florida Keys and the western Florida Peninsula Saturday night through Sunday morning, the NHC warned Friday. Tornadoes area a danger with all hurricanes, none more so than Hurricane Beryl, which spawned a whopping 67 tornadoes in July.
Could the storm rapidly intensify?
As the system moves through the eastern Gulf of Mexico this weekend, it has the potential to evolve quickly, AccuWeather said Friday. "While moving over the warm waters of the eastern Gulf, the tropical rainstorm could gain strength quickly since the atmosphere will be more moist and disruptive breezes, known as wind shear, will be low," said AccuWeather meteorologist Alex Sosnowski, in an online post.
Another meteorologist, the University of Miami's Brian McNoldy, said on his blog Friday that "Due to extremely warm water temperatures in the northeast Gulf, the possibility of rapid intensification can't be ignored."
Rapid intensification is a process in which a storm undergoes accelerated growth: The phenomenon is typically defined to be a tropical cyclone (whether a tropical storm or hurricane) intensifying by at least 35 mph in a 24-hour period.
"Rapid intensification occurs when a tropical storm or hurricane encounters an extremely conducive environment," Colorado State University hurricane researcher Phil Klotzbach said last year. "Typically, this environment consists of very warm water, low vertical wind shear and high levels of midlevel moisture."
As of Friday afternoon, according to the official forecast from the NHC, the highest wind speed that Debby is forecast to attain is 65 mph, still below the 74 mph needed to achieve hurricane status.
Bottom line: Be prepared
Although an organized storm has not formed yet, forecasters still advised folks to be prepared: "Residents from Louisiana to Florida's west coast have to be ready in case it rapidly intensifies," AccuWeather lead long-range expert Paul Pastelok said Thursday.
The National Weather Service in Tampa on Thursday said, "for now, the bottom line is monitor the progress of this system, and check your hurricane preparedness plan."
With heavy rain in the forecast, "consider your vulnerability to flooding," the NWS said.
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Atlantic storm tracker
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Atlantic storm spaghetti models
Illustrations include an array of forecast tools and models, and not all are created equal. The hurricane center uses only the top four or five highest performing models to help make its forecasts.
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What is a tropical wave?
A tropical wave is a meteorological term, referring to an elongated area of low pressure, or cyclonic curvature maximum moving east to west across the tropics, according to the National Weather Service. They are also known as an easterly wave, and can lead to the formation of a tropical storm.
What needs to happen for Tropical Storm Debby to form?
If the storm brewing over the Caribbean, dubbed Potential Tropical Cyclone Four, has winds reach 39 mph, the system would receive the name Tropical Storm Debby, and it would be the fourth named storm of what's predicted to be an extremely active 2024 Atlantic hurricane season.
When is the Atlantic hurricane season?
The Atlantic hurricane season runs from June 1 through Nov. 30.
The peak of the season is Sept. 10, with the most activity happening between mid-August and mid-October, according to the Hurricane Center.
Contributing: Gabe Hauari, USA TODAY. Ellessandra Taormino and Cheryl McCloud, Fort Myers News-Press; Reuters
This article originally appeared on USA TODAY: Storm tracker: Tropical Storm Debby to form near Florida this weekend
