Forecasters warn that by the weekend, southern California and Nevada may be hit with torrential rainfall and flash floods from Hurricane Hilary.
The National storm Center warns that this weekend, the storm may have "significant impacts" on the Baja California Peninsula.
Southwestern United States, including rainfall of up to 12 inches in the Southern California highlands.
The hurricane center said that by Thursday night, Hilary had strengthened to a Category 3 storm, with maximum sustained winds of 110 mph.
Category 2 rating in the afternoon. On Sunday, it is expected to be close to or over the central Baja coast, and by Monday, it will have moved into California.
Forecasters say Hilary has a good chance of becoming the first tropical storm to hit California since 1939.
Despite not making landfall, Tropical Storm Kay last year caused significant rainfall and floods to Southern California.
Samantha Connolly, a meteorologist with the National Weather Service in San Diego, said in a Thursday morning prediction.
the region might be hit hard by the storm due to the heavy rainfall, the possibility of flash floods, and the strong winds.