Article first published: Tuesday, Sep. 24, 2024, 4 a.m. ET

Article last updated: Tuesday, Sep. 24, 2024, 1 p.m. ET

According to the National Hurricane Center’s 1 pm Tuesday advisory, the weather system had gained sufficient intensity to be named Helene. The potential tropical cyclone had upgraded to a tropical storm with winds of 45 mph. Tropical Storm Helene is 175 miles east-southeast of Cozumel Mexico and 175 miles south of the Western Tip of Cuba, with maximum sustained wind of 45 mph. It’s moving 12 mph to the west-northwest. Portions of the Florida Gulf coast under a hurricane watch and a storm surge watch, forecasters report.

The system, which has been named Helene, has become a tropical storm with sustained winds of 45 mph after undergoing intensification from a potential tropical cyclone.

YESTERDAY (Monday):

The National Hurricane Center released the first advisory for a potential tropical cyclone at 10 am yesterday (Monday). A storm surge watch and a tropical storm watch have been issued by forecasters for a portion of southwest Florida.

CHANGES WITH THIS ADVISORY:

The government of the Cayman Islands has discontinued the Tropical Storm Warning for Grand Cayman.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Watch is in effect for:

– Indian Pass southward to Flamingo

– Tampa Bay

– Charlotte Harbor

A Hurricane Watch is in effect for:

– Cabo Catoche to Tulum, Mexico

– Cuban province of Pinar del Rio

– Englewood to Indian Pass

– Tampa Bay

A Tropical Storm Warning is in effect for:

– Dry Tortugas

– Lower Florida Keys west of the Seven Mile Bridge

– Rio Lagartos to Tulum, Mexico

– Cuban provinces of Artemisa, Pinar del Rio, and the Isle of Youth

A Tropical Storm Watch is in effect for:

– Middle Florida Keys from the Seven Mile Bridge to the Channel 5 Bridge

– Flamingo to south of Englewood

– West of Indian Pass to Walton Bay County line

A Storm Surge Watch means there is a possibility of life- threatening inundation, from rising water moving inland from the coastline, in the indicated locations during the next 48 hours. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov.

A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within the next 36 hours.

A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous.

A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours.

Wind and storm surge warnings will likely be required for the U.S. later today.

HAZARDS AFFECTING LAND:

RAINFALL: Helene is expected to produce total rain accumulations of 4 to 8 inches over western Cuba and the Cayman Islands with isolated totals around 12 inches. Over the eastern Yucatan Peninsula, 4 to 6 inches of rain are expected with isolated totals over 8 inches. This rainfall brings a risk of considerable flooding.

Over the Southeastern U.S., Helene is expected to produce total rain accumulations of 4 to 8 inches with isolated totals around 12 inches. This rainfall will likely result in areas of considerable flash and urban flooding, with minor to moderate river flooding likely, and isolated major river flooding possible.

For a complete depiction of forecast rainfall associated with Helene, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_at4.shtml? Rainqpf and the Flash Flood Risk graphic at hurricanes.gov/graphics_at4.shtml? Ero.

STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide…

Ochlockonee River, FL to Chassahowitzka, FL…10-15 ft Chassahowitzka, FL to Anclote River, FL…6-10 ft Indian Pass, FL to Ochlockonee River, FL…5-10 ft Anclote River, FL to Middle of Longboat Key, FL…5-8 ft Tampa Bay…5-8 ft Middle of Longboat Key, FL to Englewood, FL…4-7 ft Englewood, FL to Bonita Beach, FL…3-5 ft Charlotte Harbor…3-5 ft

For a complete depiction of areas at risk of storm surge inundation, please see the National Weather Service Peak Storm Surge Graphic, available at hurricanes.gov/graphics_at4.shtml? PeakSurge.

Storm surge could raise water levels by as much as 2 to 4 feet above normal tide levels in areas of onshore winds along the southern coast of Pinar del Rio, Cuba, including the Isle of Youth.

Storm surge could raise water levels by as much as 2 to 4 feet above ground level in areas of onshore winds within the warning area along the east coast of the Yucatan Peninsula.

WIND: Hurricane conditions are possible within the watch areas in Cuba and Mexico by early Wednesday. Hurricane conditions are possible within the U.S. watch areas Wednesday night and early Thursday. Tropical storm conditions are expected in the warning areas in the Cuba and Mexico today. Tropical storm conditions are expected in the warning area in the Lower Florida Keys beginning on Wednesday, and are possible in the watch area in the Middle Florida Keys beginning late Wednesday.

SURF: Swells generated by Helene will affect the southern coast of Cuba and the Yucatan Peninsula of Mexico during the next couple of days. Swells will spread northward toward the west coast of Florida and the northeastern Gulf Coast on Wednesday and Thursday. These swells are likely to cause life-threatening surf and rip current conditions.

Source: National Hurricane Center