SAN DIEGO — The Tropical Storm Watch has been upgraded to a Tropical Storm Warning across Southern California as Hurricane Hilary continues moving north.

The warning was issued at 8 p.m., impacting areas within San Diego, Orange, Riverside, San Bernardino and Los Angeles counties.

A full list of impacts for communities in the warning area can be found here.

According to the National Weather Service, a Tropical Storm Warning means that tropical storm conditions — such as strong winds or heavy precipitation — are expected to set in within 36 hours.

Hilary’s window for tropical storm force winds are expected to be Saturday night into early Sunday for those in the warning areas, weather officials said. Previous forecasts indicated that this impact would hit Sunday afternoon.

Heavy rainfall associated with Hilary is also anticipated for much of the Southern California region, NWS said, reaching its peak Sunday into Monday morning.

Rainfall amounts forecasted range from three to six inches in the Warning area, with isolated amounts of 10 inches. According to NWS, dangerous to “locally catastrophic” flooding will be likely, particularly for residents in mountain and desert neighborhoods.

Large swells generated by Hilary will also affect Southern California over the next few days, NWS said, which can cause life-threatening surf and rip current conditions.

With the upgrade to a warning, NWS officials urge that residents in Southern California prepare for extreme conditions as soon as possible. This includes readying your household for power outages, downed trees, difficult travel and evacuations due to flooding.