Will Invest 91L become tropical storm or Hurricane Gabrielle? What can Florida expect?

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With the peak of the Atlantic hurricane season less than a week away, forecasters are keeping a close eye on Invest 91L.

The system is expected to become a tropical depression over the weekend as it approaches the Lesser Antilles, according to the latest advisory from the National Hurricane Center.

AccuWeather forecasters said the “budding tropical rainstorm has a high risk of organizing into a full-fledged tropical storm and then strengthening into a hurricane before reaching the Caribbean by the middle of next week.”

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That sentiment was echoed by Dr. Ryan Truchelut, chief meteorologist at WeatherTiger, who works with the USA TODAY Network.

“I would watch the forecast carefully from Barbados to the Dominican Republic for a possible hurricane threat mid- or late next week,” Truchelut said Sept. 4.

The next named storm in the Atlantic basin will be Gabrielle.

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In the eastern Pacific, forecasters are watching Hurricane Kiko and Post-Tropical Cyclone Lorena.

Kiko was a Category 3 storm with 125 mph winds as of 11 p.m. Sept. 4, and some strengthening is possible today, Sept. 5. Kiko is forecast to approach the Hawaiian Islands during the early to the middle portion of next week. The risk of direct impacts from wind and rainfall is increasing.

Lorena has weakened into a remnant low but continues to pose a threat to the U.S. as it moves inland.

“Across the southwestern United States, 1 to 2 inches of rain, with isolated totals up to 4 inches, are expected across portions of Arizona and New Mexico through Saturday,” the Hurricane Center said.

Here’s the latest advisory from the National Hurricane Center as of 8 a.m., Friday, Sept. 5.

National Hurricane Center tracking Invest 91L. Will it become Tropical Storm Gabrielle?

A broad area of low pressure over the eastern tropical Atlantic, associated with a tropical wave, is producing a disorganized area of showers and thunderstorms.

Environmental conditions are favorable for development of this system, and a tropical depression is likely to form over the weekend or early next week as it moves slowly westward at 5 to 10 mph across the central tropical Atlantic.

This system is likely to be near the Lesser Antilles by the middle to latter part of next week, and interests there should monitor its progress.

• Formation chance through 48 hours: medium, 60 percent.

• Formation chance through 7 days: high, 90 percent.

Spaghetti models for Invest 91L

Special note about 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.

What other tropical waves, disturbances are in Atlantic basin?

Tropical wave 1: An eastern Caribbean tropical wave is near 65W from Puerto Rico to central Venezuela, moving west at 6 to 11 mph. Scattered moderate convection is noted behind the wave over the NE Caribbean, N of 14N.

What is an invest?

Short for investigation, the National Hurricane Center uses the term invest for areas of low pressure it is monitoring for potential development into a tropical depression or storm.

Invests are not tropical depressions or tropical storms. They’re usually clusters of showers and thunderstorms, and just because they’ve been designated as an invest does not guarantee they’ll strengthen into a tropical storm or hurricane.

Invests run from 90 to 99, followed by a letter: L for the Atlantic basin and E for those in the eastern Pacific. After 99, it starts over again and the next invest would be 90.

Once something has been designated as an invest, specialized data sets and computer models can begin, including scheduling Hurricane Hunter aircraft missions and running spaghetti models.

Are there any hurricanes coming toward Florida?

It’s still too early to tell whether Invest 91L poses a threat to Florida or the U.S.

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“As usual, the most likely eventual outcome is a path well east of the U.S. East Coast, but there’s enough uncertainty in where the storm will be and what the steering current pattern will be like beyond next week to make the situation worth lightly monitoring for U.S. interests,” Truchelut said.

“I would watch the forecast carefully from Barbados to the Dominican Republic for a possible hurricane threat mid- or late next week.”

“People in the northeast Caribbean should closely monitor forecast updates,” said AccuWeather Hurricane Expert Alex DaSilva, adding the system could strengthen quickly once it starts to organize.

“Due to large amounts of dry air currently in the region, any tropical development and strengthening would likely be gradual. But, it’s possible that anything that forms could ramp up to a hurricane by the end of the weekend,” DaSilva said.

When is tropical activity expected to increase?

“While there will be a relative lull in tropical activity during the first few days of September, atmospheric conditions will become a lot more conducive for development later this week and into next week,” said DaSilva.

More tropical waves are expected to move off the coast of Africa. With less dust and dry air in the way, it’s likely more of these waves will strengthen, according to AccuWeather.

Colorado State University predicting tropics to become more active

In its two-week forecast for Sept. 3-16, Colorado State University forecasters are predicting activity will pick up over the next couple of weeks.

“Global model ensembles are pretty aggressive with additional tropical cyclone development in days 8 through 14, with potential formations in the eastern Atlantic as well as in the western Caribbean/southern Gulf,” the CSU forecast said.

“The primary threat formation area for major hurricanes in early- to mid-September is in the eastern and central tropical Atlantic.”

Warm water fuels tropical development so watch Gulf closely

The Gulf will bear watching, AccuWeather forecasters warned.

“With very warm waters, the Gulf could fuel the rapid strengthening of any tropical system that develops or moves into the region.”

What do the colored, hatched areas on the NOAA map mean?

The hatched areas on the National Hurricane Center’s tropical outlook map indicate “areas where a tropical cyclone — which could be a tropical depression, tropical storm or hurricane — could develop,” said National Hurricane Center Deputy Director Jamie Rhome.

The colors make it visibly clear how likely a system could develop, with yellow being low, orange medium, and red high.

The National Hurricane Center generally doesn’t issue tropical advisories until there is a named storm, but there is an exception.

“If a system is near land and there is potential for development, the National Hurricane Center won’t wait before it issues advisories, even if the system hasn’t become an actual storm. This gives residents time to prepare,” Rhome said.

Who is likely to be impacted by Invest 91L, tropical wave?

It’s too early at this time to determine if there will be any impact to Florida or the U.S. from Invest 91L or the tropical wave in the Caribbean.

➤ Excessive rainfall forecast

Forecasters urge all residents to keep an eye on the tropics and to always be prepared.

What should be in a hurricane kit? Buy needed supplies tax free

Officials regularly encourage Florida residents to prepare for storms before a hurricane is approaching, while shelves are fully stocked and you aren’t battling crowds all rushing to the store at the same time.

“It only takes one storm to make it an impactful year for your community,” the National Hurricane Center Miami posted on X. “Hurricane season is a marathon, not a sprint.”

➤ See list of emergency supplies you can now buy tax free

On Aug. 1, specific hurricane supplies became permanently tax-free in Florida, ranging from batteries to generators.

➤ Don’t have a hurricane supply kit? From the basics to the extras, here’s what you need

Here are some of the basics you should have:

• Non-perishable food

• Two-week supply of medications

• Flashlight

• A go-bag with essential supplies in case you need to leave quickly

• Portable cellphone chargers

• Battery-operated radio

• List of emergency phone numbers, including those for family members

• Copy of your insurance policy

Florida weather radar for Sept. 5, 2025

Weather watches and warnings issued in Florida

When is the Atlantic hurricane season?

The Atlantic hurricane season runs from June 1 through Nov. 30.

Ninety-seven percent of tropical cyclone activity occurs during this time period, NOAA said.

The Atlantic basin includes the northern Atlantic Ocean, Caribbean Sea and Gulf of America, as the Gulf of Mexico is now known in the U.S. per an order from President Trump. NOAA and the National Hurricane Center are now using Gulf of America on its maps and in its advisories.

When is the peak of hurricane season?

The peak of the season is Sept. 10, with the most activity happening between mid-August and mid-October, according to the Hurricane Center.

Hurricane names for 2025 season

Here are the names for the 2025 Atlantic hurricane season, along with how to pronounce them. The first hurricane of the season typically forms Aug. 11.

• Andrea  (June 20)

• Barry  (June 29)

• Chantal (July 5)

• Dexter: (Aug. 3)

• Erin: (Aug. 11; hurricane Aug. 15; major hurricane Aug. 16)

• Fernand: (Aug. 23)

• Gabrielle: ga-bree-ELL

• Humberto: oom-BAIR-toh

• Imelda: ee-MEHL-dah

• Jerry: JEHR-ee

• Karen: KAIR-ren

• Lorenzo: loh-REN-zoh

• Melissa: meh-LIH-suh

• Nestor: NES-tor

• Olga: OAL-guh

• Pablo: PAHB-lo

• Rebekah: reh-BEH-kuh

• Sebastien: se-BAS-tee-en

• Tanya: TAHN-yuh

• Wendy: WEN-dee

National Hurricane Center map: See what forecasters watching now

Systems currently being monitored by the National Hurricane Center include:

Why does NHC say ‘tropical cyclone’ on its maps instead of hurricane or tropical storm?

Tropical cyclone is the generic term used by the National Weather Service, NOAA and the National Hurricane Center for any tropical system, even if it’s in the tropical Atlantic basin.

To be more precise, a tropical cyclone is a “rotating, organized system of clouds and thunderstorms that originates over tropical or subtropical waters and has closed, low-level circulation,” NOAA sadi.

Once maximum sustained winds reach 74 mph, what it is called is determined by where it originated:

• Hurricane: for storms in the North Atlantic, central North Pacific, and eastern North Pacific.

• Typhoon: for storms in the Northwest Pacific.

• Cyclone: for storms in the South Pacific and Indian Ocean.

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This article originally appeared on Sarasota Herald-Tribune: Invest 91L expected to become tropical depression. Gabrielle next name