High pressure set up over the Four Corners region, allowing monsoonal moisture to move into Southern California on July 12th and 13th. A few thunderstorms popped up and dropped heavy rain over the mountain and desert areas.
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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.
High pressure set up over the Four Corners region, allowing monsoonal moisture to move into Southern California on July 12th and 13th. A few thunderstorms popped up and dropped heavy rain over the mountain and desert areas. There was also some lightning associated with these storms. Total lightning count: 45 cloud-to ground strikes and 677 total flashes.
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 Jul 13, 12:18 PM PST, 42 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
118 PM PDT Sat Jul 13 2019
.SYNOPSIS...
High pressure centered near the Four Corners region will maintain
hot conditions inland through early next week. A shallow marine
layer will keep coastal areas cooler, with areas of night and
morning low clouds and fog. Isolated showers or thunderstorms are
still possible through this evening along and east of the mountain
crests. The high will give way to a developing trough along the West
Coast next week, which will deepen the marine layer and spread
modest cooling inland.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Satellite imagery around the Noon hour showed a large coastal eddy
over the CA Bight. Stratus was extensive offshore and extended to
many beaches. Farther east high clouds were drifting north over the
mts/deserts with some convective clouds over the mts. Surface
pressure gradients continued to trend onshore but were weak. Peak
wind gust reports were over the high desert area and SW 20-30 MPH.
Dewpoints were higher today over the lower deserts and mts which
have contributed to the shwr/tstm threat and also held temps a bit
lower than yesterday. No echoes were detected on radar through 1 PM
PDT.
No big changes to our outlook for the coming week. The subtropical
high over the rockies will broaden as a trough in the westerlies
moves inland to the north. This shifts the axis of highest pressure
aloft farther to the SW and creates modest height rises over SoCal
into Sunday. This will tighten up the sfc pressure gradient onshore,
but also maintain the hot airmass over the deserts. After Sunday
there is a slow decrease in amplitude of the subtropical ridge and a
corresponding increase in the trough along the West Coast. This will
initiate a cooling trend with moderate onshore flow and a deeper
marine layer after Monday. The stronger onshore flow may shave a
couple of degrees off of the max temps in the I.E./high deserts on
Sunday/Monday, but it will still be quite hot before the sea breeze
is fully developed, especially far inland. The cooling will be more
noticeable inland by midweek.
Mid-level winds may have discouraged thunderstorm development
through 1 PM PDT, but the threat remains as those winds weaken
slightly and afternoon heating continues. Any thunderstorm threat
will diminish after this evening as the flow aloft turns more
southwesterly, bringing in dry and more stable air.
&&
.FIRE WEATHER...
High pressure aloft will continue hot and dry days inland through
Monday. A shallow marine layer will keep coastal areas cooler with
higher humidity. Isolated showers or thunderstorms are still
possible near the mountain crests and desert slopes this afternoon
and early evening. The main threats with any storms will be gusty
outflow winds and isolated dry lightning.
&&
.AVIATION...
132000Z...Coast...Persisting low clouds along immediate coast will
push ashore after 02Z and locally inland overnight. Bases will start
out 1000-1500 feet MSL, but lower overnight after 09Z to 800 feet
along with lower vis 2-5SM after 11Z. Clear out Sunday by 17-18Z,
but with low clouds persisting again along immediate coast.
Valleys/Mountains/Deserts...Cumulus clouds around 10000 feet over
the mountains and adjacent deserts through 02Z this afternoon,
leading to a slight chance of tstorms from the crests to the desert
slopes. Clearing overnight. Otherwise, mostly clear with
unrestricted vis through Sunday.
&&
.MARINE...
No hazardous marine weather expected through Thursday.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory until 8 PM PDT Monday for San Bernardino and
Riverside County Valleys-The Inland Empire.
Excessive Heat Warning until 8 PM PDT Monday for Coachella
Valley-San Diego County Deserts.
PZ...NONE.
&&
PUBLIC/FIRE WEATHER...10
AVIATION/MARINE...MMThe national radar mosaic for the moment the first event began.
1 heavy rain. Local standard time, as filed.
COOP Observer in Mount Laguna recorded 2.04 inches of rain in one hour between 1300 and 1400 PST. No flooding or damage was reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2019Every state in 2019This day in weather historyWarnings in California, July 2019
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 2026-09-30. Each event’s entry at NCEI: 845972.