Hurricane Helene won’t directly hit SC, but will have wide-reaching effects. What to know

As Hurricane Helene churned at 10 mph in the Caribbean Sea on Wednesday morning, forecasters predicted the system would become stronger and larger as it marched northward, setting off a series of warnings and watches across the Southeast.

Helene was expected to rapidly intensify over the Gulf of Mexico, growing into a major hurricane before hitting Florida’s Big Bend region late Thursday, according to the National Hurricane Center early Wednesday .

Before the chaos, predicted to spike storm surge up to 15 feet and whip up damaging winds in some areas of Florida, several Florida counties were issued evacuation orders, nearly all were under a state of emergency and a series of storm watches and warnings were triggered for a handful of Southeast states.

In South Carolina and Georgia, the National Weather Service issued a tropical storm warning Wednesday for all of the coast north of Altamaha Sound to the South Santee River.

While some unknowns remain about Helene, here’s what to know about the hurricane’s path, size, predicted impacts and preparation.

When will Helene make landfall?

Helene could strengthen into a Category 3 hurricane before making landfall, with computer models showing the storm will reach land near Florida’s Big Bend Coast late Thursday, according to the National Hurricane Center’s 7 a.m. Wednesday advisory .

The Big Bend region was rattled by Hurricane Idalia in August 2023 and Hurricane Debby in August.

How large is the storm?

Forecasters said Helene is a large system — its wind field is expected to span 400 miles — and will have impacts reaching “well outside/east of the tracking cone.” When Helene is nearest Tampa Bay on Thursday morning, the storm’s wind field was predicted to be nearly 430 miles wide, with the vast majority of it on the east side.

Helene’s wind field “is forecast to be larger than 90% of hurricanes,” said John Morales, a hurricane specialist for NBC5 .

As of Wednesday mid-morning, the system was packing sustained 80 mph winds, classifying it as a Category 1 hurricane .

What does rapid intensification mean?

Rapid intensification happens when there is an increase in the maximum sustained winds of a tropical cyclone of at least 35 mph in a 24-hour period, the National Hurricane Center said.

A 2022 study published by Advancing Space and Earth Sciences reported most major hurricanes – Category 3 or higher – rapidly intensify at some point when the system moves into warm surface waters and low wind shear .

What’s the storm surge prediction for Lowcountry coastal areas?

Storm surge between 1 and 3 feet above ground is possible starting Wednesday, with the greatest impacts Thursday.

The surge alongside predicted rainfall along the Lowcountry coast — between 1 and 3 inches — could cause localized flooding in low-lying areas, washing of streets and roads near the coast minor-to-moderate beach erosion, according to the National Weather Service’s Charleston Office .

What about rainfall counts for the state?

The forecast predicted between 5 and 10 inches of rain in the western part of South Carolina, with isolated amounts up to 15 inches possible in the Upstate, according to the National Weather Service. In the Lowcountry, up to 3 inches of rain could fall between Wednesday and Friday evenings.

The majority of rainfall is expected Thursday but will persist into Friday morning. The onslaught could cause localized flooding in low-lying areas, washing of streets and roads near the coast minor-to-moderate beach erosion.

On Thursday, when the majority of rain was predicted to fall, Hilton Head Island’s high tide Thursday will reach 7.2 feet at 4:21 a.m. and its evening high tide will spike to 8.6 feet at 2:50 p.m., according to the U.S. Harbors’ site . In Beaufort, Thursday’s high tide will climb to 6.8 feet at 4:37 a.m. and the evening high tide will reach 7.6 feet at 5:18 p.m.

Are there other storm threats to South Carolina?

Tornadoes are a concern for Thursday night, the South Carolina Emergency Management Division said . The Storm Prediction Center had identified a slight risk of severe weather for areas south and east of Interstate 20, and an enhanced risk — level 3 of 5 — for the far southern part of the state.

Morales said the service was becoming more concerned about tornadoes, because the current environment is a “very good setup” for tornadoes to form. The highest threat for tornadoes is within stronger rain bands.

“We expect the radar to get a lot busier a lot busier later tonight and certainly tomorrow, as we start getting into the actual rain bands of circulation,” Morales said.

Frank Strait, the state’s severe weather liaison, said a tornado outbreak at night is “never a good thing,” as people are usually sleeping and miss warnings.

“It’s important to have tornado preparations in place ahead of Helene,” Strait said. “Decide on your best shelter area in advance, as you might not get much lead time. Tropical tornadoes often hit fast without much lead time on warnings.”

Beaufort County does not have tornado sirens, so ensure you have a way to get alerts for tornado watches and warnings.

• CodeRED : Download the free CodeRED Mobile Alert app from the Google Play or iTunes store.
• Everbridge : Download the free Everbridge app from the Google Play or iTunes store.

• Other options : NOAA Weather Radio, News media coverage, Emergency Alert System on radio and TV broadcasts.

What about wind speeds?

There is a potential for tropical-storm-force wind and wind gusts, with the highest threat along and south of a line from Allendale to Beaufort. Strong winds can lead to downed and/or uprooted trees, isolated-to-scattered power outages and impassable roads covered in debris.

Over coastal waters, Thursday and into Friday morning, seas could build 6 to 15 feet, with 9 to 17 feet as the, highest, and winds and wind gusts of up to 55 knots are possible.

Along South Carolina’s southeast coast, there will be a threat of high surf and deadly rip currents Thursday and Friday, the NWS said.

What prep is necessary for Beaufort County residents?

According to the state’s Emergency Management Division, there are several ways to prepare before Tropical Storm Helene rattles the Southeast.

• Build an emergency kit : Ensure you have enough food, water, medications and other necessities to last at least 72 hours.
• Clear gutters and drains : Clear your gutters and storm drains of debris to prevent water accumulation and reduce the risk of flooding around a home.
• Secure outdoor items : Store or secure outdoor furniture, garden tools and toys. High winds can turn these objects into dangerous projectiles.
• Stay informed : Monitor local weather forecasts about the developments of the storm. Have several ways to get emergency information.

Are there closures in the county?

As of Wednesday mid-morning, Beaufort County schools, and city and county offices had not announced closures due to Hurricane Helene.

What is the threat level to neighboring coastal Georgia?

On Tuesday, Georgia Gov. Brian Kemp declared a State of Emergency ahead of Hurricane Helene and several counties were under a tropical storm watch .

Savannah, Tybee Island and Ossabaw Island were expected to get similar rain, wind and storm surge conditions as the South Carolina Lowcountry.