hello, everyone. thank you so much for joining me. i'm fredericka witfield. the southwestern u.s. is bracing for potentially catastrophic flooding as hurricane hilary churns off the pacific. we just learned moments ago that the storm has weakened just a bit to a category 3 storm with 125 mile an hour winds. it's lashing mexico with strong winds and high waves right now. forecasters warn it could dump more than a year's worth of rain across parts of california, nevada and arizona. the storm is expected to weaken as it moves north, but the threat is so severe, a tropical storm watch has been issued for california, the first ever for that state. people there are trying to prepare as best they can. cnn meteorologist allison chinchar is joining us.