(NEW YORK) -- Hurricane Hilary is heading toward Southern California where it is forecast to bring heavy rain, flash flooding, mudslides and gusty winds.
The greater Southwest area, including Las Vegas, could also see flash flooding from this very rare event.
Hilary is gaining strength in the Pacific Ocean and is expected to become a major Category 4 hurricane by Friday afternoon as it tracks along Baja California. A tropical storm watch is in effect for Cabo San Lucas as Hilary's outer bands could graze the popular Mexican resort town on Saturday.
As Hilary approaches California, it's expected to weaken to a tropical storm, but is still forecast to bring a significant punch to Southern California and the Southwest.
Some areas in California's inland desert could see their annual rainfall in just 48 hours.
If Hilary does make landfall in California, it would be the first tropical storm to do so since 1939. The ocean water off the Mexican coast, where Hilary is currently churning, is much warmer than normal.