Isaias becomes the first hurricane of the Atlantic season as it heads toward the US Gulf Coast

Isaias strengthened into the first hurricane of the Atlantic season late Wednesday as it surged towards the U.S. Gulf Coast, the National Hurricane Center said.

Forecasters warned that it was on track to make landfall between the Mississippi coast and the Florida Panhandle late Friday or early Saturday and was expected to bring heavy rains and potentially flash flooding.

The center of the cyclone was about 460 miles south-southwest of the Mississippi River, with maximum sustained winds around 75 mph, according to an advisory from the Miami-based hurricane center.

Isaias is developing more than four months into the Atlantic hurricane season, tying a 121-year-old record for the area’s latest-forming hurricane.

According to the National Weather Service, the record dates to 1905, when the year’s first Atlantic hurricane formed on Oct. 8.

The Atlantic hurricane season has been unusually quiet this year because of a strong El Niño, which disrupts storm formation over that ocean. Storm activity has been above average in the Pacific, where Tropical Storm Simon also formed Wednesday off Mexico.