Tropical Storm Karl dumped heavy rains on the Yucatan Peninsula on Thursday as it moved toward the Gulf of Mexico, where it is expected to pick up steam and become a hurricane threatening Mexico's central coast by the weekend. In the Atlantic, forecasters say Hurricane Igor has spun into a major Category 4 storm and is threatening to generate life-threatening rip currents along the U.S. East Coast over the weekend and to bring large swells to the Bahamas and Virgin Islands before that. Category 3 Hurricane Julia is not a threat to land. In Mexico, the government issued a hurricane watch for its eastern Gulf Coast from La Cruz in Tamaulipas state south to Nautla in Veracruz. It is expected to reach the coast on Saturday. Karl made landfall on Yucatan about 30 miles (50 kilometers) up the coast from the Quintana Roo state capital of Chetumal on Wednesday, with winds of about 65 mph (100 kph), according to the U.S. National Hurricane Center in Miami. It hit about midway between the cruise ship port of Majahual and the coastal town of Xcalak, the Associated Press reported.