A Flood Watch has been issued by the National Weather Service and is in effect from Friday afternoon through Saturday evening.
The areas included are: San Bernardino County Mountains-Riverside County Mountains-San Diego County Mountains-Apple and Lucerne Valleys-Coachella Valley-San Diego County Deserts-San Gorgonio Pass Near Banning-Including the cities of Julian, Big Bear Lake, La Quinta, Big Bear City, Running Springs, Pine Valley, Lucerne Valley, Hesperia, Palm
Springs, Idyllwild-Pine Cove, Wrightwood, Crestline, Victorville, Coachella, Palm Desert, Borrego Springs, Apple Valley, Cathedral City, Lake Arrowhead, Palm Desert Country, and Indio.
There could be flooding Friday afternoon through Saturday evening caused by excessive rainfall in a portion of Southwest California, including the following areas: Apple and Lucerne Valleys, Coachella Valley, Riverside  County Mountains, San Bernardino County Mountains, San Diego County Deserts, San Diego County Mountains and the San Gorgonio Pass Near Banning.
Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations.
Moisture associated with tropical cyclone Kay, off the San Diego coast, is expected to bring periods of rain, heavy at times, in the mountains and deserts. The heaviest rain will likely be Friday night and Saturday.
You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop.