Hurricane Irma expected Thursday

UPDATE HERE: Fast-forming Hurricane Irma could be Cat 3 storm by Thursday night

Tropical Storm Irma continued to gather strength overnight and will likely become a hurricane Thursday, National Hurricane Center forecasters said.

In their latest advisory, forecasters said sustained winds had picked up to 70 mph and were likely to keep building as the storm rolled west at 12 mph into warm tropical waters. Irma was located about 590 miles west of the Cabo Verde Islands.

In the coming days, the storm will encounter low wind shear, allowing it to intensify. It’s expected to encounter some dry air, but not enough to wring it out, they said. They expect it to remain over the tropical Atlantic at least through Tuesday.

While it’s still not clear what impacts it will have to land, track models show it steering more to the southwest on a more ominous course for Florida and the U.S. coast. It’s expected to turn slightly south in the next two days in response to a high pressure system.

Over the next five days, forecasters said there’s a chance winds could reach 120 mph, making Irma a major Cat 3 hurricane.

Forecasters said they are also keeping an eye on a low pressure system in the Gulf of Mexico that could bring additional rain to heavily flooded parts of the Texas and Louisiana coasts. It’s too soon to tell how much rain and forecasters gave the system just a 20 percent chance of forming.

This story was originally published August 31, 2017 at 7:18 AM with the headline "Hurricane Irma expected Thursday."