Subtropical moisture from the remnants of Hurricane Linda brought widespread showers to most of the area, deserts included. The first isolated thunderstorm developed on the 6th in San Diego County as a moisture surge in monsoon warm upper level flow arrived.
Every event with a place to put it. 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.
Subtropical moisture from the remnants of Hurricane Linda brought widespread showers to most of the area, deserts included. The first isolated thunderstorm developed on the 6th in San Diego County as a moisture surge in monsoon warm upper level flow arrived. Intense heavy rain from thunderstorms occurred on the 7th with flash flooding in several locations including Victorville and Forest Falls. A swift water rescue in Victorville was successful, but another incident in Forest Falls had one rescue but a drowning occurred when a 30-year-old couple crossed Mill Creek and were swept away. Most areas received between a few hundredths to one-third of an inch of rain, with a few upslope areas of the San Bernardino Mountains receiving up to around one inch. Additional thunderstorms developed on the 8th by noon over the mountains and quickly spread into the Inland Empire and Orange County, as well as near I-15 in San Diego County. Locally heavy rain and several trees and poles were downed in the Riverside area including a small dust storm. Several hail reports, mostly nickel-sized, but a few larger. Activity decreased on the 9th with only isolated thunderstorms formed.
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 7, 12:34 PM PST, 2 hours 26 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
134 PM PDT MON SEP 7 2015
.SYNOPSIS... HIGH PRESSURE WILL BUILD OVER THE REGION THIS WEEK
BRINGING VERY WARM TO HOT WEATHER. IN ADDITION...MOISTURE SWIRLING
AROUND TROPICAL CYCLONE LINDA WILL BRING INCREASED HUMIDITY...
PERIODS OF CLOUDS...AND A CHANCE FOR ISOLATED SHOWERS AND
THUNDERSTORMS IN THE MOUNTAINS DURING THE AFTERNOONS. LITTLE IN THE
WAY OF COOLING OR MARINE CLOUDS CAN BE EXPECTED UNTIL SOMETIME NEXT
WEEKEND WHEN THE HIGH BEGINS TO WEAKEN AND ONSHORE FLOW INCREASES.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
HEAT ADVISORY ISSUED FOR THE INLAND EMPIRE AND INLAND ORANGE COUNTY
TUESDAY THROUGH FRIDAY.
SATELLITE IMAGERY EARLY THIS AFTERNOON SHOWED CLEAR AND SUNNY SKIES
OVER MOST OF THE REGION...WITH PUFFY CUMULUS AND AN OCCASIONAL
TOWERING CUMULUS LINING THE MOUNTAIN RIDGES. SURFACE PRESSURE
GRADIENTS WERE RUNNING ABOUT 4 MBS OFFSHORE FROM NV...AND 3 MBS
ONSHORE TO THE LOWER DESERTS. LIGHT WINDS WERE REPORTED MOST AREAS.
AT MIDDAY...TEMPERATURES WERE RUNNING 4-8 DEGREES ABOVE VALUES
OBSERVED YESTERDAY. EXPECT ADDITIONAL WARMING THROUGH MIDWEEK AS
HIGH PRESSURE BUILDS OVER THE AREA...AND SURFACE PRESSURE GRADIENTS
REMAIN WEAKLY OFFSHORE FROM THE GREAT BASIN. MODELS SHOW A THERMAL
TROUGH BECOMING BETTER DEVELOPED ALONG OR JUST OFFSHORE EACH MORNING
THIS WEEK. THIS KEEPS MARINE AIR FROM TEMPERING THE DIURNAL
TEMPERATURE RISE UNTIL LATER IN THE DAY. THE WEAKENED SEA BREEZE AND
RELATIVELY WARM SEA SURFACE WILL ALLOW TEMPERATURES TO INCREASE TO
10 TO 15 DEGREES ABOVE AVERAGE INLAND TO THE COASTAL SLOPES MUCH OF
THIS WEEK. A HEAT ADVISORY HAS BEEN ISSUED BEGINNING ON TUE. PLEASE
SEE LAXNPWSGX FOR FURTHER DETAILS.
A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IS IN THE FORECAST OVER
THE MTS EACH AFTERNOON DUE TO ELEVATED PW FROM AROUND 1.5 TO NEAR 2
INCHES. INSTABILITY HOWEVER WILL BE MARGINAL WITH THE HIGH PRESSURE
CENTER MOVING OVER THE REGION BY MIDWEEK. THE 12Z NAM12 SHOWS A
DECREASE IN MID-LEVEL WINDS ON TUE...WHICH MAY GIVE THE SHOWERS A
BETTER CHANCE TO DEVELOP OVER THE HIGHER TERRAIN. SLIGHT CHANCE POPS
ARE IN THE FORECAST OVER THE MTS EACH AFTERNOON THROUGH THU.
HIGH CONFIDENCE FORECAST FOR THE SUBTROPICAL HIGH OVER TEXAS TO
RETROGRADE TO A POSITION OVER NV BY FRI. INCREASING HEIGHT/THICKNESS
OVER SOCAL...COUPLED WITH WEAK OFFSHORE GRADIENTS TO THE NE...WILL
PUSH MAX TEMPS WELL ABOVE AVERAGE. SIGNIFICANT COOLING IS NOT
EXPECTED UNTIL SOME TIME NEXT WEEKEND AT THE EARLIEST...WHEN THE
HIGH ALOFT IS FORECAST TO WEAKEN.
HURRICANE LINDA HAS BECOME A MAJOR STORM WITH MAXIMUM SUSTAINED
WINDS OVER 100 MPH. THE STORM IS CENTERED ABOUT 370 MILES SW OF CABO
SAN LUCAS AND WAS HEADING NW AT 14 MPH. THE NHC TRACK HAS THE STORM
COMING ABOUT AS FAR NORTH AS 26 DEGREES...THEN TURNING SHARPLY WEST
OFF OF PUNTA EUGENIA...BAJA CA. THE MODELS PULL THE DEEPEST TROPICAL
MOISTURE NORTH TO ABOUT THE MEXICAN BORDER AND WELL OUT TO SEA.
WHILE THE TRACKS OF LINDA AND DOLORES...BACK IN JULY...ARE
SIMILAR...DOLORES CAME NORTH WITH A TROUGH ALONG THE WEST COAST
WHICH WAS ABLE TO PULL THE DEEPER TROPICAL MOISTURE MUCH FARTHER TO
THE NORTH. HIGH PRESSURE OVER THE AREA SHOULD PREVAIL AND MAKE FOR A
MUCH DIFFERENT OUTCOME HERE.
BOTH THE LATEST OPERATIONAL RUNS OF THE GFS/ECMWF LOOK VERY
DIFFERENT FOR NEXT WEEK...BUT BOTH FAVOR SOME SEMBLANCE OF TROUGHING
ALONG THE WEST COAST EARLY NEXT WEEK. HOWEVER...THE SOLUTIONS
DIVERGE BY MIDWEEK...WHICH DECREASES CONFIDENCE IN ANY SUSTAINED
COOLING. BOTH LOOK MOSTLY DRY.
&&
.AVIATION...
072030Z...COAST/VALLEYS...MOSTLY CLEAR SKIES WITH UNRESTRICTED VIS
WILL PREVAIL THROUGH TUE...EXCEPT FOR OCCASIONAL MID/HIGH CLOUDS
ABOVE 10000 FT MSL.
MOUNTAINS/DESERTS...ISOLATED THUNDERSTORMS WILL OCCUR OVER THE
MOUNTAINS THIS AFTERNOON...MAINLY OVER SAN DIEGO COUNTY. BASES WILL
BE AT/ABOVE 9000 FT MSL WITH TOPS TO 35000 FT MSL...AND THERE WILL
LIKELY BE STRONG UP/DOWNDRAFTS IN THE VCNTY AND LOCAL SURFACE WINDS
OVER 35 KNOTS. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS AGAIN
TUESDAY AFTERNOON OVER THE MOUNTAINS. OTHERWISE...OCCASIONAL
MID/HIGH CLOUDS ABOVE 10000 FT MSL AND UNRESTRICTED VIS WILL PREVAIL
THROUGH TUE.
&&
.MARINE... 130 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH
SATURDAY.
&&
.BEACHES... 130 PM...A SOUTHWEST SWELL WITH A LONG PERIOD WILL
SLOWLY FADE TONIGHT AND TUESDAY. THIS WILL PRODUCE HIGH SURF AND
STRONG RIP CURRENTS. THE HIGH SURF ADVISORY IS IN EFFECT UNTIL 8 PM
TUESDAY...SEE LAXCFWSGX. ALSO CHECK THE SURF FORECAST FOR
DETAILS...LAXSRFSGX.
HURRICANE LINDA IS CURRENTLY ABOUT 950 MILES SSE OF SAN DIEGO...OR
ABOUT 450 MILES SW OF CABO SAN LUCAS. THE SYSTEM SHOULD BEGIN TO
ENTER OUR SWELL WINDOW LATE TUESDAY...WITH SWELL AT AROUND 5 FEET/12-
13 SECONDS...MOVING INTO THE COASTAL WATERS THURSDAY. HOWEVER...THE
SWELL WILL BE FROM 165-170 DEGREES...WHICH WILL PRIMARILY JUST
AFFECT THE MOST SOUTHERN ORIENTED BEACHES OF ORANGE COUNTY...WITH
SOME SETS LOCALLY 6 TO 8 FEET THERE LATE THU/FRI.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HEAT ADVISORY FROM NOON TUESDAY TO 7 PM PDT FRIDAY FOR ORANGE
COUNTY INLAND AREAS-SAN BERNARDINO AND RIVERSIDE COUNTY
VALLEYS-THE INLAND EMPIRE-SANTA ANA MOUNTAINS AND FOOTHILLS.
HIGH SURF ADVISORY UNTIL 8 PM PDT TUESDAY FOR ORANGE COUNTY
COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
PZ...NONE.
&&
PUBLIC...JAD
AVIATION/MARINE/BEACHES...MAXWELLThe San Diego radar (KNKX), 58 km away, was scanning. The volume nearest the first event began at 22:58 UTC.
7 flash flood, 2 hail, 1 lightning, 1 thunderstorm wind, 1 flood. Local standard time, as filed.
CHP reported mud and rocks on Highway 78 near Yaqui Pass, closing Highway 78. CHP also reported flash flooding Highway S2 from mile marker 36 to mile marker 44, blocking the southbound lanes.
A trained spotter reported quarter-sized hail and extremely heavy rain.
CHP reported a rock/mudslide blocking the roadway at Highway S-22 near San Felipe Road.
Public reported quarter-inch hail.
A flash flood at Mill Creek crossing...40 feet wide and 8 to 12 inches deep. The head of the flash flood was 3 to 4 feet deep. From Victor Valley news group: flood waters overtook a couple hiking. An off-duty sheriff's deputy heard the couple calling for help and was able to save the young woman, but the man was swept away. The body of the victim, a Rancho Cucamonga man in his 20s, was found shortly after 1800 PST.
Multiple swift water rescues along Bear Valley Road. Water flowed fast down the road with some areas of water around 5 feet deep. A spotter reported water 4-6 deep at the intersection of Bear Valley Road and Apple Valley Road.
Valley of the Falls Drive is washed out and the road was closed.
CHP reported a lightning-started brush fire along Highway 38 near Onyx Peak.
CHP reported a power pole down with live wires in the roadway near the intersection of Cowie Avenue and Lopez Road.
An NWS employee reported a flash flood on Highway 79 in Aguanga leaving 1 foot of mud on the roads. Crews were still cleaning up mud the following day.
CHP reported vehicle stuck in flood waters at Marshall Street and Lopez Road.
A male and a female were in a flood control channel and had to be rescued by the Orange County Fire Department when they were caught off guard by the quickly rising water.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Flash Flood, San Bernardino | 2015-09-08 | 25 | Male | In Water | Direct |
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: 602867, 602868, 602869, 602870, 602871, 602872, 602873, 602874, 602875, 602877, 602876, 602878.