Hilary updates: Over 1 foot of rain hits San Bernardino as LA avoids catastrophe
Hilary soaked Southern California, flooding roads and knocking out power.
All tropical storm warnings have been canceled across Southern California as the remnants of Hilary, which no longer meet the threshold of a tropical cyclone, track north.
Once a Category 4 hurricane, Hilary tore through Southern California with historic rainfall on Sunday, flooding roads and knocking out power.
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Evacuation warning issued for areas of San Bernardino County
The San Bernardino County Sheriff's office has issued an evacuation warning to residents in parts of the county.
"An evacuation warning is not an evacuation order -- it's a warning to people to be on notice they could be asked to evacuate at any moment," San Bernardino County spokesperson David Wert told ABC News. "The purpose is to warn the population that there is an impending danger. They should start making arrangements to evacuate."
The storm is expected to hit San Bernardino County "pretty hard," Wert said, noting there is a threat of debris flowing into areas downstream of recent brushfires.
"Hopefully the order won't come, but we want people to be ready," Wert added.
-ABC News' Samira Said
Rare 'high risk' forecast for excessive rainfall issued
The National Oceanic and Atmospheric Administration's Weather Prediction Center issued a rare "high risk" forecast for excessive rainfall for Sunday across a large swath of Southern California, from Palm Springs up toward Death Valley.
"High risk" forecasts are only issued a couple times a year on average, and 39% of all flood-related fatalities and 83% of all flood-related damages in the U.S. occur on those days.
A "moderate risk" for extreme rainfall has also been issued from Las Vegas to San Diego and Los Angeles. Numerous flash floods could unfold in these areas as well, with some of them potentially significant and very dangerous.
The deadliest hazard associated with tropical cyclones over the past decade is flooding from heavy rain.
-ABC News' Dan Peck
Southern California expected to see tropical storm winds Sunday
Winds from Hilary will reach tropical storm strength in Southern California on Sunday afternoon as the storm passes by.
Heavy rainfall is expected across the southwestern U.S., peaking late tonight through Sunday night. Rainfall amounts of 3 to 6 inches, with isolated amounts of 10 inches, are expected across portions of Southern California and southern Nevada. Dangerous to catastrophic flooding is expected.
Elsewhere across portions of the western U.S., rainfall totals of 1 to 3 inches are expected, resulting in localized, some significant, flash flooding.
-ABC News' Kenton Gewecke
Hurricane Hilary downgraded to a category 3 storm
Hurricane Hilary has entered cooler water and is starting to weaken, now a category 3 hurricane with sustained winds reaching 125 mph as it moves north-northwest at 16 mph.
Landfall is expected in Mexico on Sunday. The storm is then expected to be at tropical storm strength as it enters southern California, marking the first tropical storm in Southern California since Nora in 1997, more than 25 years ago.
Catastrophic and life-threatening flooding is expected in Southern California.
Rain from Hilary should reach California later Saturday. Early morning monsoonal showers have lead to flash flooding Saturday morning, but that is not associated with Hilary.
-ABC News' Kenton Gewecke
Latest maps show path of storm over the Southwest
The National Weather Service has issued a flash flood warning for parts of Southern California as the region begins to experience the effects of Tropical Storm Hilary.
Los Angeles County, including downtown Los Angeles, and Ventura County were included in the advisory.
Heavy rain is now becoming more widespread across portions of the region. The heaviest rain is focused over much of the Interstate 5 corridor, north of San Diego into Los Angeles.
Rainfall rates up to 1 inch per hour are possible in this area, and flash flooding will likely develop, forecasts show.
Rounds of heavy rain are expected to continue to sweep across the greater Los Angeles metro area through the next several hours.
Hilary will then move northward over the next 24 hours. As the system moves over land, it will weaken and become disorganized but could remain a tropical storm as it tracks across Southern California.
A tropical storm warning remains in effect for San Diego, Palm Springs, Riverside and Los Angeles.
Flood watches remain across a large swath of the Southwest, including cities like San Diego, Palm Springs, and Las Vegas. These watches have also been extended northward up to Idaho for the potential for heavy rain and flash flooding early in the week.
The National Oceanic and Atmospheric Administration's Weather Prediction Center has issued a high risk alert for excessive rainfall across Southern, California, from Palm Springs to San Bernardino and up to Death Valley. "High Risk" days are rare and typically dangerous -- 39% of all flood-related fatalities and 83% of all flood-related damages in the U.S. occur on "High Risk" days, records show.
A moderate risk alert for extreme rainfall is in effect from Las Vegas to San Diego and Los Angeles.
The biggest rainfall totals will be across the mountains east of San Diego, north and east of Los Angeles. Through Monday, a widespread 1 to 3 inches of rain is forecast across much of Southern California, the desert Southwest and across southern Nevada.
Three to 6 inches or more of rain is forecast across the mountains areas in Southern California. Several inches could still fall in some desert locations, with the greatest chance closer to Death Valley. Isolated amounts of 6 to 10 inches are still possible in some regions.
One to 2 inches of rainfall quickly falling in a desert location can cause major impacts due to the oversaturated soil.
-ABC News' Daniel Peck