A broad upper level Pacific trough moved through the West Coast on September 14-15 and tapped into remnant tropical cyclone Linda moisture west of the California Bight. Widespread and locally heavy rainfall developed across the entire CWA with 1 to 2 inches of rainfall common.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS SGX wrote it up.
A broad upper level Pacific trough moved through the West Coast on September 14-15 and tapped into remnant tropical cyclone Linda moisture west of the California Bight. Widespread and locally heavy rainfall developed across the entire CWA with 1 to 2 inches of rainfall common. The heavy rain resulted in a major traffic impact during the morning commute in LA and Orange County, along with a debris flow in Silverado Canyon, and widespread urban flooding in San Diego, Orange, Riverside and San Bernardino Counties.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS San Diego, CA wrote its last area forecast discussion before the first event at Sep 15, 3:28 AM PST, 3 hours 2 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE SAN DIEGO CA 428 AM PDT TUE SEP 15 2015 .SYNOPSIS... MOISTURE FROM THE REMNANTS OF FORMER HURRICANE LINDA WILL BRING PERIODS OF SHOWERS INTO EARLY WEDNESDAY...MAINLY ALONG AND WEST OF THE MOUNTAINS. DRY WEATHER WITH A WARMING TREND WILL FOLLOW THROUGH NEXT WEEKEND. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... THIS UPDATE IS TO INCREASE RAIN CHANCES TODAY AND TO INCREASE RAINFALL AMOUNTS FOR TODAY THROUGH EARLY EVENING BASED ON UPSTREAM RAINFALL AMOUNTS ACROSS VENTURA AND LOS ANGELES COUNTIES THE PAST FEW HOURS. OVERNIGHT...THE GREATEST COVERAGE OF SHOWERS HAS BEEN ACROSS VENTURA AND SOUTHERN LOS ANGELES COUNTIES AND ADJACENT COASTAL WATERS WITH MORE WIDELY SCATTERED COVERAGE EXTENDING SOUTHWARD ACROSS THE COASTAL WATERS OF ORANGE AND SAN DIEGO COUNTIES EXTENDING LOCALLY INLAND AS WELL AS ALONG THE COASTAL SLOPES OF THE MOUNTAINS. MOST RAINFALL AMOUNTS THROUGH 3 AM FOR ORANGE AND SOUTHWESTERN SAN BERNARDINO COUNTIES SOUTHWARD HAVE BEEN ONE TENTH INCH OR LESS. UPSTREAM AMOUNTS IN LOS ANGELES AND VENTURA COUNTIES FOR THE THREE HOURS THROUGH 4 AM WERE MOSTLY ONE QUARTER TO ONE HALF INCH WITH LOCAL AMOUNTS TO ONE INCH. COVERAGE OF SHOWERS ALONG AND WEST OF THE MOUNTAINS IS EXPECTED TO INCREASE DURING THE MORNING WITH GREATEST COVERAGE AND AMOUNTS SPREADING SOUTHWARD FROM ORANGE COUNTY AND SOUTHWESTERN SAN BERNARDINO COUNTY DURING THE AFTERNOON AND EARLY EVENING INTO SAN DIEGO COUNTY AS A WEAK SHORTWAVE MOVES SOUTHWARD THROUGH SOUTHERN CALIFORNIA TODAY. SHOWERS ARE EXPECTED TO DECREASE OVERNIGHT AND END EARLY WEDNESDAY. RAINFALL AMOUNTS COULD RANGE FROM AROUND THREE QUARTERS OF AN INCH NEAR THE COAST TO 1.5 TO 2.5 INCHES IN THE MOUNTAINS WITH LOCALLY GREATER AMOUNTS. THE GREATEST RAINFALL AMOUNTS ARE EXPECTED ALONG THE SOUTH SLOPES OF THE SAN BERNARDINO COUNTY MOUNTAINS. THIS RAINFALL COULD CAUSE PONDING OF WATER ON ROADWAYS PRONE TO COLLECTING WATER DURING PERIODS OF RAINFALL. FOR THURSDAY THROUGH NEXT WEEKEND...THE TROUGH OF LOW PRESSURE ACROSS THE SOUTHWEST STATES WILL WEAKEN WITH DRY WEATHER AND A WARMING TREND. THERE REMAIN SMALL CHANCES FOR AN INFLUX OF TROPICAL MOISTURE FROM THE SOUTHWEST EARLY NEXT WEEK. && .AVIATION... 150900Z...COASTS/VALLEYS/MOUNTAINS...EXPECT MULTIPLE LAYERS OF CLOUDS VARYING IN BASES FROM 1500-4500 FEET MSL EXTENDING UP TO 12000 FEET ALONG WITH SCATTERED SHOWERS THROUGH THIS AFTERNOON. MODERATE CONFIDENCE THAT SOME SCATTER OUT WILL OCCUR THIS AFTERNOON...BUT MOSTLY REMAINING BROKEN AT AROUND 3000-4000 FEET MSL WITH ISOLATED SHOWERS THIS EVENING THROUGH TONIGHT. AREAS OF COASTAL SLOPES OF THE MOUNTAINS OBSCURED IN CLOUDS/FOG/RAIN THROUGH TONIGHT. DESERTS...GUSTY WESTERLY WINDS OF 35-45 MPH WITH HIGHER GUSTS MAINLY IN FAVORED LEE AREAS OF MOUNTAIN GAPS AND INTO ADJACENT DESERTS LATE AFTERNOON THROUGH EVENING. ISOLATED SHOWERS TODAY MOST LIKELY IN THE HIGH DESERT WITH CLOUDS AOA 8000 FEET MSL. MOSTLY CLEAR AFTER 02Z. && .MARINE... 200 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH SATURDAY. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && PUBLIC...17 AVIATION/MARINE...MM
The Santa Ana Mts radar (KSOX), 44 km away, was scanning. The volume nearest the first event began at 14:30 UTC.
4 flood, 3 flash flood, 1 heavy rain, 1 debris flow, 1 tsunami. Local standard time, as filed.
A spotter reported the right lane of the Pacific Coast Highway flooded at the intersection with Main Street...road was nearly impassable.
An Orange County Emergency Manager reported a debris flow 2 feet deep over Silverado Canyon Road at Maple Springs Truck Trail. Further downstream, there was another debris flow at Silverado Canyon Road and Oak Lane, but the road was still passable.
One house had damage inside from flooding on the San Manuel Indian Reservation, while a second house had flooding on the outside, but did not sustain any damage inside. This was dubbed the Victoria Weather Incident by the San Bernardino County EOC.
TV media reported several vehicles stuck in flood waters at Grove Avenue and Francis Street in Ontario. Also, Peyton Drive in Chino Hills was shut down in both directions south of Eucalyptus Avenue due to flooding.
Valley Blvd. was flooded between Hermosa and Grand Avenues.
The CBS affiliate in Los Angeles reported two westbound lanes on the 91 freeway at Green River Road in Corona experienced a 50-yard crack as water penetrated the soil underneath the pavement. An emergency repair of the road took place and multiple lanes were closed.
CHP reported the #4 lane of the Avenida Pico southbound on-ramp to I-5 south was completely flooded.
Several businesses in the Midway District were flooded...with water up to knee deep. Several vehicles were flooded in an underground parking garage in Ocean Beach, including a brand new Lamborghini luxury car flooded halfway deep.
A debris flow along slide creek closed Valley of the Falls Drive, the main road going into Forest Falls. Also, Mill Creek experienced moderate flooding below Forest Falls.
An 8.3 magnitude earthquake that struck off the coast of Chile on the 16th led the National Tsunami Warning Center to issue a tsunami advisory at 1743 PST for a swath of California, from Orange County to north of San Luis Obispo. No action was necessary in San Diego County, the Center determined. All beaches, harbors, piers, and marinas in the Cities of Seal Beach, Huntington Beach, Newport Beach, Laguna Beach, Dana Point and San Clemente, including County and State beaches were closed through 0500 PST on the 17th. Tsunami wave heights were observed to be just under one foot along the Orange County coast. The Orange County EOC reported no significant coastal flooding occurred, but to be aware of the high likelihood of strong currents and waves dangerous to persons in or near the water. The advisory was lifted around 1100 PST on the 17th.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2015Every state in 2015This day in weather historyWarnings in California, September 2015
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 603052, 603051, 603056, 603057, 603058, 603054, 603053, 603055, 603059, 603060.