A storm surge warning was in effect for the area between Shell Beach, Louisiana, and Dauphin Island, Alabama, with predicted heights of up to 3-5 ft if the peak surge coincides with high tide. A number of schools called off classes, people rushed to fill bags with sand, and red no-swimming flags flew along the shore as waves kicked up from the approaching storm. The storm is expected to reach hurricane strength when it hits the Gulf Coast, including coastal MS, by late Tuesday.
In Louisiana, Gov. John Bel Edwards declared a state of emergency Monday and said 200 National Guard troops will be deployed to southeastern Louisiana.
The Louisiana coastal town of Grand Isle has also issued a voluntary evacuation order.
What had been Tropical Storm Florence reached hurricane strength late Tuesday morning.
The storm left many businesses on Florida's Gulf Coast feeling shortchanged by the holiday weekend.
Separately, the Atlantic was expected "to stay active" in the coming days, the National Hurricane Center said.
The last time there was no hurricane between July 13 and September 3, peak season, was in 2013, Klotzbach said. The storm was expected to reach coastal Mississippi and Louisiana by late Tuesday and move inland over the lower Mississippi Valley on Wednesday.
"Gordon will not be just a coastal event, and not just wind but also water could be damaging, risky and even deadly, especially if preparations are not rushed to completion as early as possible today before tropical storm conditions arrive", said Rick Knabb, The Weather Channel's tropical weather expert.
Residents in parts of South Florida, Mississippi, and Louisiana are being warned to prepare for tropical storm-force winds with the onset of Tropical Storm Gordon.
A hurricane watch - meaning that hurricane conditions are possible - was put into effect for the area stretching from the mouth of the Pearl River in MS to the Alabama-Florida border.
Tornado threat is possible, but the threat appears limited. More than 4,000 Florida Power & Light customers lost power Monday due to weather conditions.
By Sep. 3 afternoon the storm had passed over Florida's southern tip.
The worst-hit areas could see up to five feet of flooding.
Alert Day Wednesday: continued tropical storm conditions with widespread rain and a chance for thunderstorms. A Flash Flood Watch is in effect.
The center said in its 8:30 a.m. EDT advisory that the storm was centered 20 miles (30 kilometers) west of Key Largo and 85 miles (135 kilometers) southeast of Marco Island. It was moving west at 15 miles per hour, pushing maximum sustained winds of 70 miles per hour with higher gusts.Forecasters said that little change in strength was expected and that no coastal watches or warnings were in effect. This is a fast moving storm, which means that the impacts will be slightly less than if it was a system that moved slowly bringing constant high winds and storm surge to the coast.