At the time, peak sustained winds were 45 miles per hour, but wind gusts were in the 50 mph-to-60 miles per hour range.
Tropical Storm warnings are also in effect for the coasts of Alabama, Mississippi and Louisiana.
Rain is the main concern as South Florida is expected to get 2-4 inches Monday with 4-6 inches on the Gulf Coast.
The current wind pattern is expected to gradually change and lead the storm over the eastern and central Gulf of Mexico by Tuesday or Wednesday. Last year's hurricane season battered the southern USA states and Puerto Rico, killing thousands and causing hundreds of billions of dollars' worth of damage.
The storms closest point of approach to Bermuda in the next three days is expected to be 1344 nautical miles east south east of the island. Some rain showers and storms are possible in the morning, and a few of the storms could produce flash flooding.More news: Man opens fire on crowd, shot by police outside Ice Cube concert
Meteorologist Danielle Niles of CBS' Boston station WBZ says the threat along the Gulf Coast means heavy rain as well as storm surge. That system is given a low chance of becoming a tropical storm over the next five days.
AccuWeather meteorologists have said they can not rule out the potential for the system to become a hurricane in the Gulf.
Gordon, the seventh named storm of the season, was expected to form once it reached the warm waters of the Gulf of Mexico, but spun up a little before the forecast predicted.
The NHC said: "The combination of a risky storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline". Impacts are likely to start by Tuesday though much uncertainty remains in the intensity of the system.