Tropical Storm Idalia strengthened in the Gulf of Mexico as it bore down on Florida, where it’s forecast to make landfall as a hurricane as soon as Wednesday, promising to bring flooding rain to Cuba, Mexico and the southeastern US. With top winds of 40 miles (64 kilometers) per hour, Idalia was drifting east off Mexico’s Yucatan Peninsula, the US National Hurricane Center said in an update at 11:15 a.m.