Tropical Storm Helene is expected to become a hurricane when it passes the Yucatan Peninsula Wednesday, according to the National Hurricane Center in Miami.

Helene is expected to rapidly intensify into a major and massive hurricane with 115-mph winds by the time it makes landfall Thursday.

Hurricane Helene is forecast to rapidly intensify over the record-warm Gulf of Mexico before slamming into the United States’ Gulf Coast later this week. The storm has not formed yet but is expected to soon, so the National Hurricane Center has dubbed it Potential Tropical Cyclone Nine to warn of its imminent threat.