Tropical Storm Helene Gaining Strength, Forecast To Strike Florida As Large, Dangerous Hurricane

 

At a Glance

• Hurricane, storm surge and tropical storm warnings have been issued for parts of Florida.
• Helene will become a hurricane in the Gulf of Mexico by Wednesday.
• A hurricane landfall is likely along the Florida Gulf Coast Thursday night.
• The hurricane could be both strong and large at landfall with life-threatening storm surge, damaging winds and flooding rain.
• Locally strong winds and heavy rain will push well inland in parts of the South into Friday.

T​his means hurricane, tropical storm and storm surge conditions are either expected (warnings) or possible (watches) in these areas within the next 36-48 hours.

Interests in the warned areas should implement their hurricane plans and heed any advice from local emergency managers.

Where is it now: Helene became the eighth storm of the 2024 Atlantic hurricane season late Tuesday morning and is moving in the general direction of Cancún, Mexico.

Helene's thunderstorms continue to coalesce over its center of circulation, a sign of its increasing organization.

Here is the timeline:

-​ Wednesday: Helene's center will make its closest approach to Cancún and Cozumel, likely as a hurricane, with the potential for high winds, surge flooding and heavy rain. Bands of heavy rain and strong winds will still hammer parts of western Cuba. Helene will then enter the southern Gulf of Mexico, intensifying and growing in size. Some high surf and outer rainbands could reach parts of Florida's Gulf Coast from the Keys to the Panhandle, and tropical moisture intercepting a front could wring out heavy, flooding rain in parts of the Tennessee Valley from Georgia into east Tennessee.

-​ Thursday: Helene is expected to reach its peak intensity in the eastern Gulf and then make a landfall somewhere along the Gulf Coast of Florida as a large hurricane Thursday night. While computer forecast models suggest the most likely location for a landfall is in Florida's Big Bend region, remember that hurricane impacts (surge, winds, rain) often happen far from the center, particularly in larger storms.​ These track forecasts could still change. So, everyone along and near the Florida Gulf Coast should continue to monitor the forecast for any last-minute changes.

-​ Friday: Helene will sweep quickly northward through the Southeast toward the southern Appalachians and Ohio Valley with lingering areas of strong wind gusts, locally flooding rain and isolated tornadoes.

(Further beef up your forecast with our detailed, hour-by-hour breakdown for the next 8 days – only available on our Premium Pro experience.)

Current Storm Status And Projected Path

(The red-shaded area denotes the potential path of the center of the tropical cyclone. It's important to note that impacts (particularly heavy rain, high surf, coastal flooding, winds) with any tropical cyclone usually spread beyond its forecast path. )

How strong could it become: Helene could reach major hurricane intensity in the Gulf ahead of landfall.

That's because heat content is one favorable ingredient for intensification, and the map below shows there is plenty of deep, warm water in the northwest Caribbean Sea and parts of the Gulf of Mexico's loop current. In fact, Gulf of Mexico heat content is at record high levels for this time of year, according to University of Miami tropical scientist Brian McNoldy.

Therefore, Helene could rapidly intensify until it reaches its peak intensity Thursday.

One other factor to consider is wind shear. Wind shear typically limits or weakens tropical storms and hurricanes by either tilting their circulation or blowing more thunderstorms away from its core.

L​ower wind shear should allow Helene to fully take advantage of that deep, warm water. Some increase in shear may arrive near landfall, but by that time, it may not have much impact on an already strong, large hurricane.

(For even more granular weather data tracking in your area, view your 15-minute details forecast in our Premium Pro experience.)

(This map shows areas of not only warm water, but warm, deep water that is one ingredient to fuel developing and active tropical cyclones.)

U.S. I​mpacts

Helene is forecast not only to be a hurricane, but also large in size and may move faster both as it approaches the coast and pushes well inland. As we discussed in a previous piece, that will affect the scope and severity of Helene's impacts.

S​torm Surge

The National Hurricane Center's storm surge forecast is shown in the map below. As you can see, much of the Florida Gulf Coast is expected to see at least some storm surge flooding, including areas as far south as the Keys.

T​he highest storm surge is expected along and to the east of where Helene's center makes landfall. For now, that appears to be the Big Bend, Apalachee Bay and Nature Coast of Florida. Some surge inundation could top 10 feet above ground level in these areas, especially if the peak surge arrives at high tide. For Cedar Key, that could be a record storm surge, and easily could be several feet higher than Hurricane Idalia's peak in August 2023 (6.84 feet).

G​iven Helene's anticipated large wind field, significant storm surge flooding is also expected in the Tampa-St. Pete-Sarasota metro areas that could be higher than what was experienced over a year ago with Hurricane Idalia.

I​f you live near the coast, know your evacuation zone and heed any advice or orders from local emergency management.

Storm Surge Forecast

(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.)

Winds

A​s alluded to earlier, Helene will be both a large and fast-moving storm in the Gulf and then as it plows inland. That means its strong winds will cover a larger area than usual.

Hurricane-force winds are not only possible along a stretch of Florida's Gulf Coast in areas covered by hurricane alerts, but these high winds may also penetrate well inland into parts of northern Florida and far southern Georgia Thursday night. Downed trees and power outages could be widespread in these areas, and even some structural damage is possible.

T​ropical storm-force winds will quickly spread up western Florida's coast to the panhandle in the areas shown below Thursday into Thursday night. These tropical storm-force gusts could then push well inland into much of Georgia and parts of the Carolinas Thursday night into Friday. Some downed trees and power outages are quite possible in these areas.

NWS Peak Wind Threat

(This map from the National Weather Service shows the potential strongest winds (likely in gusts) that could occur. Areas in red or purple colors are most probable to see hurricane-force capable of more widespread tree damage, power outages and at least some damage to buildings. Areas in yellow and orange could see at least some sporadic downed trees and power outages. )

R​ainfall

Helene will produce heavy rainfall generally along and to the east of its track not just near the coast, but well inland over the Southeast into the Ohio Valley this weekend.

T​he heaviest rain is expected Thursday into Friday in parts of the Southeast, but some bands of heavy rain are expected well ahead of Helene Wednesday in parts of the Southeast, including the Atlanta metro area. And some pockets of locally heavy rain could last into Saturday in parts of the Ohio Valley and Florida.

W​idespread 4-inch-plus rainfall totals can be expected from Florida's Gulf Coast as far north as Kentucky, West Virginia and Virginia. Some areas may see up to 12 inches of rain in the Florida Panhandle and the southern Appalachians.

This rain could lead to flash flooding, especially where it combines with storm surge and over higher terrain, where some landslides are possible. This wet, soggy ground may also make it easier for Helene's winds to topple trees.

Rainfall outlook

(While not all of the rainfall shown above is from this tropical system, this should be interpreted as a broad outlook of where the heaviest rain may fall. Higher amounts may occur where bands or clusters of thunderstorms stall for over a period of a few hours.)

Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. Extreme and bizarre weather are his favorite topics. Reach out to him on X (formerly Twitter), Threads, Facebook and Bluesky.