▶ Watch Video: Tropical Storm Idalia forms in the Gulf of Mexico

A state of emergency has been expanded and schools in Florida are closing as Tropical Storm Idalia threatens to unleash “life-threatening” storm surge and “dangerous” winds on the state after strengthening into a major hurricane

A hurricane warning was in effect Monday for Florida’s Gulf Coast stretching from the middle of Longboat Key to the Ochlockonee River, including Tampa Bay, according to the National Hurricane Center. A hurricane watch was in effect from Englewood, Florida, to the middle of Longboat Key, and from the area west of the Ochlockonee River to Indian Pass. 

The storm is expected to hit Florida’s Gulf coast on Wednesday, forecasters said.   

Meanwjile, to the east of Idalia, Hurricane Franklin churned in the Atlantic, where the Category 3 hurricane threatened to heavy swells to Bermuda and the U.S. East Coast throughout the week.  

What category of storm will Hurricane Idalia be?

Idalia is expected to grow into a hurricane on Monday as it nears western Cuba, which it is expected to pass near or over. Forecasters then expect the storm to strengthen into a Category 3 hurricane.

“This is going to be a major impact,” Florida Gov. Ron DeSantis said at a news conference Monday. “And Floridians should expect that this storm will be a major Cat 3+ hurricane, so please prepare accordingly.”

Members of the Tampa, Fla., Parks and Recreation Dept., help residents with sandbags on Aug. 28, 2023, in Tampa, Fla. Residents along Florida’s gulf coast are making preparations for the effects of Tropical Storm Idalia.

Chris O’Meara/AP

Category 3 storms have sustained wind speeds of 111-129 mph and are expected to produce devastating damage, including downed trees, major damage to homes and days- or weeks-long cuts to electricity and water, the hurricane center says. 

A Category 3 storm — like a Category 4 or 5 — is considered a “major” hurricane due to the potential for “significant loss of life and damage,” the National Hurricane Center says. 

State of emergency expanded

DeSantis has expanded a state of emergency to cover an additional 13 Florida counties, bringing the total number of counties under the declaration to 46. He first issued a state of emergency on Saturday for 33 of the state’s 67 counties to ensure communities “have time to prepare for the storm system which could have impacts along the Gulf Coast next week.”

“There are going to be evacuation orders issued in all these Gulf Coast counties in the A and B zones. All the barrier islands, places that re low-lying on the coast, you are going to be told to evacuate,” DeSantis said Monday.

He said all counties in Idalia’s path should have their emergency evacuation centers activated now and added they should request aid from the state as soon as possible.  

His office said over the weekend the Florida National Guard was mobilizing 1,100 personnel to support areas of the state that are impacted. Additionally, 12 aircraft and 2,400 high wheel vehicles were being mobilized.

Which Florida schools are closed due to Idalia?

Schools across at least 10 Florida counties will be closed this week. According to the Florida Department of Education:

  • Citrus County Schools will have a half day Monday and will be closed Tuesday and Wednesday.
  • Dixie County Schools will be closed Tuesday and Wednesday.
  • Gilchrist County Schools will be closed Tuesday and Wednesday.
  • Hernando County Schools will be closed Monday through Wednesday.
  • Hillsborough County Schools will be closed Tuesday and Wednesday.
  • Jefferson County Schools will have an early release day Tuesday and will be closed on Wednesday.
  • Levy County Schools will be closed Tuesday and Wednesday.
  • Manatee County Schools will close Nolan Middle, Freedom Elementary, Miller Elementary and Mills Elementary at 12 p.m. Monday.
  • Marion County Schools will be closed Tuesday and Wednesday.
  • Pasco County Schools will be closed Tuesday and Wednesday.

The education department added that Pasco-Hernando State College, Florida Gateway College and North Florida College will also have closures, which come as some parts of state are forecast to see up to 12 inches of rain.

“Areas of flash and urban flooding, some of which may be locally significant, are expected across portions of the west coast of Florida, the Florida Panhandle, and southern Georgia Tuesday into Wednesday, spreading into portions of the eastern Carolinas Wednesday into Thursday,” the National Hurricane Center said. 

Storm surge is also expected. The water level could reach as high as 11 feet in the area between the Aucilla River and Chassahowitzka, Florida, if storm surge coincides with high tides. It could reach as high as 7 feet is other areas, including Tampa Bay, according to the hurricane center. 

What is storm surge?

Storm surge is “an abnormal rise of water generated by a storm,” according to the National Hurricane Center. As a storm moves toward the coast, water is pushed to the shore and “piles up,” which creates a surge. 

If a storm surge and high tide take place at the same time, water levels will be even higher. The combination is known as storm tide. 

Storm surge is one of the deadliest hazards of a hurricane. It is also “a very complex phenomenon,” according to the hurricane center,” because it depends on factors including a storm’s wind speeds, size and angle of approach to the coastline, as well as the shape and characteristics of the coast.

A storm surge warning is in effect for Englewood north to the Ochlockonee River, including Tampa Bay, and a storm surge watch is in effect for Chokoloskee to Englewood, including Charlotte Harbour; Ochlockonee River to Indian Pass, Florida; and the mouth of the St. Mary’s River to Altamaha Sound, Georgia.  

Nicole Brown Chau contributed to this article.