An upper-level trough off the SoCal coast pulled tropical moisture from former Hurricane Paine northward into the area, bringing unsettled weather from the 19th-21st. Unusual lightning activity occurred over the San Diego Metro on the 19th.
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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.
An upper-level trough off the SoCal coast pulled tropical moisture from former Hurricane Paine northward into the area, bringing unsettled weather from the 19th-21st. Unusual lightning activity occurred over the San Diego Metro on the 19th. San Diego and Riverside Counties saw unseasonable rainfall, with one-quarter to one-half of an inch falling over the coastal and valleys, and one-half to one and a half inches in the mountains and deserts. The rainfall delayed a San Diego Padres baseball game at Petco Park on the 20th, and increased September rainfall to more than 200% of normal over San Diego and Riverside Counties. When the trough moved through the region on the 22nd strong winds surfaced in the deserts bring areas of blowing dust and sand.
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 19, 2:51 AM PST, 2 hours 9 minutes earlier.
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
351 AM PDT MON SEP 19 2016
.SYNOPSIS...
A shallow marine layer and weak onshore flow will bring areas of
dense fog near the coast early this morning. A low pressure system
off the Southern California coast will draw mid level moisture
from Hurricane Paine into Southern California with scattered
showers and isolated thunderstorms with dry lightning. More
substantial moisture will spread northward into Southern
California for tonight and Tuesday with more clouds and greater
chances for showers and isolated thunderstorms...continuing into
Wednesday. For Thursday...a low pressure system moving inland
through the West will bring strong onshore flow with
cooling...drying...and strong west winds in the mountains and
deserts. Warmer and dry for next weekend with periods of weak
offshore flow.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (Today through Wednesday)...
A low pressure system off the Southern California coast will draw
mid level moisture from Hurricane Paine northward across the
coastal waters and adjacent coastal areas of Southern California
this morning with scattered showers and isolated thunderstorms.
Rainfall is expected to be limited. At lower levels...widespread
stratus over the coastal waters beneath a shallow marine inversion
will bring areas of dense fog near the coast. The increasing
moisture will bring several degrees for cooling for inland areas
today.
For tonight into Tuesday...more substantial tropical moisture will
spread northward across about the southeastern half of southern
California...but with lesser instability. This will bring more
substantial cloud cover with warmer overnight temperatures and
cooler daytime temperatures with greater chances for showers and
isolated thunderstorms.
Moisture will begin drying on Wednesday...but still be sufficient
for continuing chances of showers and thunderstorms...especially
for the mountains and deserts.
&&
.LONG TERM (Thursday through Sunday)...
A low pressure system moving inland through the West will bring
strong onshore flow across Southern California with cooling and
strong gusty west winds in the mountains and deserts. For next
weekend...strong high pressure aloft of the California coast and
weak surface high pressure over the Great Basin will bring warmer
and dry weather with periods of gusty northeast winds near the
coastal mountain slopes.
&&
.AVIATION...
190900Z...Areas of dense fog will continue along the coast with vis
near zero to 5sm and cigs around 200 feet msl with tops to 700 feet.
Vis conditions will improve by 15Z and scatter out most likely by
17Z. Meanwhile increasing higher clouds above 10000 feet msl
containing high based thunderstorms will move north through the
coastal waters today and tonight. Thunderstorms are possible over
land, but less likely this morning. Lightning, gusty surface winds,
strong up/down drafts, reduced vis from rain and small hail are all
possible near storms.
&&
.MARINE...
Fog with vis near 1sm will obscure the isolated to scattered
thunderstorms moving northward into the coastal waters this morning.
Vis will improve during the day. The thunderstorms are expected to
move northward through the coastal waters this morning, and a small
chance of thunderstorms will continue tonight through Tuesday.
Dangerous cloud-to-water lightning strikes, and gusty, erratic winds
are possible near any storms. A Marine Weather Statement is in
effect through Tuesday afternoon for the low visibility this morning
and the thunderstorm chance through Tuesday.
&&
.BEACHES...
A slight chance of thunderstorms with the threat of lightning is in
the beach forecast today through Tuesday. A beach hazards statement
will be issued if and when lightning is expected to strike the
beaches.
&&
.FIRE WEATHER...
A low pressure system off the Southern California coast will draw
mid level moisture from Hurricane Paine northward across the
coastal waters and adjacent coastal areas of Southern California
this morning with scattered showers and isolated thunderstorms.
Rainfall is expected to be limited with scattered dry lightning
strikes. More substantial tropical moisture from the south for
tonight and Tuesday will increase the potential for wetting
rainfall and decrease the dry lightning potential.
For Thursday...a low pressure system moving inland through the
western states will bring strong onshore flow across Southern
California with periods of strong gusty west winds in the
mountains and deserts.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX Watches/Warnings/Advisories...
CA...Fire Weather Watch from 6 AM PDT this morning through this
evening for Orange County Coastal Areas-Orange County
Inland Areas-Riverside County Mountains-Including The San
Jacinto Ranger District Of The San Bernardino National
Forest-San Bernardino County Mountains-Including The
Mountain Top And Front Country Ranger Districts Of The San
Bernardino National Forest-San Bernardino and Riverside
County Valleys -The Inland Empire-San Diego County Coastal
Areas-San Diego County Inland Valleys-San Diego County
Mountains-Including The Palomar And Descanso Ranger
Districts of the Cleveland National Forest-San Gorgonio
Pass Near Banning-Santa Ana Mountains-Including The Trabuco
Ranger District of the Cleveland National Forest.
Beach Hazards Statement until 8 AM PDT this morning for San
Diego County Coastal Areas.
Dense Fog Advisory until 9 AM PDT this morning for Orange County
Coastal Areas-San Diego County Coastal Areas.
PZ...None.
&&
PUBLIC/FIRE WEATHER...17
AVIATION/MARINE/BEACHES...MMThe San Diego radar (KNKX), 16 km away, was scanning. The volume nearest the first event began at 13:00 UTC.
2 dust storm, 1 lightning. Local standard time, as filed.
A band of convection formed along the leading edge of moisture from former Hurricane Paine as it moved northward. Numerous lightning strikes occurred in San Diego County setting palm trees on fire and causing power outages to 4000 customers.
Strong winds produced blowing dust and sand with visibility of 1/2 t 3/4 of a mile, impacting travel on highway 78 near Ocotillo Wells.
Strong winds produced blowing dust and sand with visibility of 1/2 t 3/4 of a mile, impacting travel in Hesperia.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2016Every state in 2016This day in weather historyWarnings in California, September 2016
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: 661636, 661638, 661639.