Updated at 4:58 p.m. ET

Hurricane Isaias will drench Florida's Atlantic coast this weekend after passing over the Bahamas, the National Hurricane Center says, warning of a dangerous storm surge, flooding and high winds.

Gov. Ron DeSantis signed an order Friday declaring "a state of emergency in every coastal county of Florida's east coast, from Miami-Dade to Nassau counties," he said.

The storm could begin affecting South Florida "as early as late tonight into tomorrow morning, with the potential to increase in strength to Category 2," DeSantis said at a news conference shortly before noon Friday.

As of now, officials don't believe the storm will require the use of shelters, the governor said. But he added that Floridians should ensure their emergency preparations are in order and be ready for potential power outages.

Isaias is currently a Category 1, with maximum sustained winds of 75 mph. But the storm is forecast to strengthen Friday night – and it's expected to remain a hurricane for several days as it plows along the southeastern U.S. coast.

North Carolina Gov. Roy Cooper also declared an emergency Friday, clearing the way for the state to move trucks and supplies more easily.

The hurricane will move "near or over the Northwestern Bahamas Saturday and near the east coast of the Florida peninsula Saturday afternoon through Sunday," the NHC says.

"Localized flooding is expected throughout the Bahamas and the Turks and Caicos Islands as Isaias is forecast to produce rainfall amounts of 4 to 8 inches," the BahamasMeteorologyDepartment said on Friday.

In Florida, a hurricane warning — meaning hurricane conditions are expected somewhere within the area — extends from Boca Raton up to the line between Volusia and Brevard counties.

The system has become better organized Friday, and it is moving northwest at around 15 mph, the NHC says. Over the next day, Isaias is expected to slow its forward motion and turn more toward the north-northwest, to hug the U.S. coastline.

"Heavy rains associated with Isaias may begin to affect the eastern Carolinas by early next week," the hurricane center says. "This rain could result in isolated flash and urban flooding, especially in low-lying and poorly drained areas, as well as isolated minor river flooding."

If evacuations and shelters become necessary in North Carolina, the governor's office says, anyone seeking shelter will be screened for COVID-19 symptoms.

"If an individual has COVID symptoms, they will be redirected to a non-congregate sheltering option where they can more easily isolate," a statement from Cooper's office says.

"Hurricane preparations will be different given the COVID-19 pandemic, and families need to keep that in mind as they get ready," Cooper said.

Safety concerns about the storm prompted the Florida Division of Emergency Management to close all state-supported COVID-19 testing sites for several days, starting Thursday evening. But that plan has since been changed, after Isaias' forecast track shifted farther to the east. On Friday, DeSantis said only testing sites on the state's eastern coast will be closed.

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