Flash Flood and Flood in California, June 21 to 22, 2022

Name: Flash Flood and Flood in California, June 21 to 22, 2022
Start: 2022-06-21T20:17
End: 2022-06-22T23:59
Location: California

June 21 to 22, 2022 · NWS SGX · 8 events in 5 counties and zones

Widespread thunderstorm activity occurred on June 21-22. Multiple small wildfires were started due to lightning strikes, and localized flooding was reported.

Where it happened

Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $1,000
Crop damage: $3,000
Events: 8

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.

What happened

The episode as NWS SGX wrote it up.

Widespread thunderstorm activity occurred on June 21-22. Multiple small wildfires were started due to lightning strikes, and localized flooding was reported.

What forecasters said that day

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 Jun 21, 8:10 PM PST, 7 minutes earlier.

Area forecast discussion, Jun 21, 8:10 PM PST, 7 minutes before

Area Forecast Discussion
National Weather Service San Diego CA
910 PM PDT Tue Jun 21 2022

.SYNOPSIS...
The first monsoon event of the summer will bring scattered
showers and isolated thunderstorms to Southern California tonight
and Wednesday. On Thursday, drier air will move in from the west,
but afternoon thunderstorms are still possible over the mountains.
Friday and Saturday will be dry and warm. Weak monsoonal flow
may return early next week.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

Radar detected a lone thunderstorm in northern Baja at 5 PM. It
moved north in the southerly flow toward Campo through 6 PM, then
weakened and dissipated as it crossed the border. No measurable rain
was reported with this cell. A second cell formed and moved over
Lakeside where a weather spotter reported a moderate rain shower at
8:30 pm.

The mid-level moisture advection today raised the Precipitable Water
from 0.52" on the NKX sounding at 12Z this morning to 0.96" on the
00Z sounding this evening. Now that the leading edge of this moist,
unstable airmass has reached SoCal, isolated showers and
thunderstorms will be possible just about anywhere in area tonight.

Mid-level lapse rates will be near 8C/km tonight and Wednesday.
The PW will steadily increase overnight and peak between 1.30-
1.50" midday Wednesday, and this is when the showers and
thunderstorms will likely be the most widespread. Most unstable CAPE
values reach 500-800J/kg.

Rainfall amounts tonight and Wednesday will be highly
variable. Although showers will be scattered over the area, some
places will miss out on the precipitation while other areas
will see a few moderate to heavy showers or thunderstorms. The
cells will be moving at a rapid pace, moving north at 25 mph in
southerly steering flow aloft, which will limit the flash flood
potential. Nevertheless, brief local flooding is possible if these
cells move over a burn scar or over an area with poor drainage.

Strong downburst winds are also possible with this inverted-V
sounding (moisture aloft and a deep dry subcloud layer below).

On Thursday the winds aloft shift westerly and force the
monsoonal moisture east, but there may be enough moisture
over the mountains and deserts Thursday afternoon for isolated
showers or thunderstorms to form.

Friday and Saturday will be dry and warm with seasonal summer
temperatures. Monsoonal moisture may return early next week for
possible storms over the mountains and deserts.

&&

.AVIATION...
220340Z....SCT CU/TCU continuing into Wednesday evening with
bases near 10,000 ft MSL and tops to 20,000-30,000 ft MSL. ISO SHRA
becoming SCT after 08Z along with a slight chance of TSRA. Vis
locally reduced to 3-5 SM in stronger SHRA/TSRA. Showers ending by
23/06Z.

Low clouds will be patchy tonight, but may impact the coastal TAF
sites for a few hours between 10-16Z. Bases will be near 1000 ft MSL
with 3-5 SM vis over higher coastal terrain. Any low clouds should
clear by 17Z.

&&

.MARINE...
There is a slight chance of showers and thunderstorms across the
coastal waters late tonight into Wednesday afternoon, with isolated
cloud-to-water lightning being the primary concern. No hazardous
weather is expected Thursday through Saturday.

&&

.FIRE WEATHER...
Monsoonal moisture will move into southern California tonight
and Wednesday bringing scattered showers and isolated
thunderstorms. Some cells with contain brief heavy rain.

Dry air will move in from the west on Thursday, but residual
moisture over the mountains could trigger a few afternoon
thunderstorms.

&&

.SKYWARN...
Skywarn activation may be requested Wednesday.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

PUBLIC/FIRE WEATHER...Moede
AVIATION/MARINE...SS

The radar

The San Diego radar (KNKX), 7 km away, was scanning. The volume nearest the first event began at 04:16 UTC.

Open the radar archive at this moment

Event by event

3 lightning, 2 wildfire, 1 flood, 1 hail, 1 flash flood. Local standard time, as filed.

Lightning, San Diego

When: June 21, 8:17 PM PST
Where: San Diego County, 2 mi NNE of Poway
Crop damage: $1,000
Reported by: Public
Coordinates: 32.977, -117.017

Public report of tree on fire from a lightning strike near Poway.

Flood, San Diego

When: June 22, 12:00 AM PST to 11:59 PM PST
Where: San Diego County, 2.76 mi NNW of Borrego Spgs to 2.75 mi NNW of Borrego Spgs
Cause: Heavy Rain
Reported by: County Official
Coordinates: 33.288, -116.394

Report from associate meteorologist at San Diego County Flood Control District. ALERT rain gauge in Coyote Canyon recorded 0.58 inch in an hour (2-year return interval). Minor flooding reported around Montezuma Road in De Anza neighborhood of Borrego Springs.

Hail, San Bernardino

When: June 22, 11:30 AM PST
Where: San Bernardino County, 4 mi SE of Big Bear City
Measured: 0.25 in hail
Property damage: $1,000
Reported by: Trained Spotter
Coordinates: 34.229, -116.800

Trained spotter, Bensweather, reports the eastern end of valley covered in light coating of hailstones as seen from camera view. Roofs and some ground covered in hail. Thunderstorm moved over the area around 12:30 pm.

Lightning, Riverside

When: June 22, 1:13 PM PST
Where: Riverside County, Palm Spgs
Crop damage: $1,000
Reported by: Public
Coordinates: 33.830, -116.550

Reports of power outage in Palm Springs and tree fire from lightning strike. Report from social media.

Wildfire, Riverside County Mountains

When: June 22, 1:29 PM PST
Where: Riverside County Mountains forecast zone
Reported by: Law Enforcement
Coordinates: 33.744, -115.994 (the zone’s center; the record gives no point)

Law enforcement reports a brush fire started by an exploding transformer.

Flash Flood, Riverside

When: June 22, 2:34 PM PST
Where: Riverside County, 2 mi WNW of Cabazon to 0.36 mi N of Owl
Cause: Heavy Rain
Reported by: Law Enforcement
Coordinates: 33.931, -116.812

Law enforcement reports roadway flooding, mostly in the #1 lane on the I-10 E near mile marker 18.

Wildfire, San Diego County Mountains

When: June 22, 2:51 PM PST
Where: San Diego County Mountains forecast zone
Reported by: Law Enforcement
Coordinates: 33.028, -116.770 (the zone’s center; the record gives no point)

Law enforcement reported a wildfire north of I-8 near McCain Valley Road. Lightning strike was reported, likely serving as the ignition source.

Lightning, San Diego

When: June 22, 3:05 PM PST to 6:30 PM PST
Where: San Diego County, Borrego Spgs
Crop damage: $500
Reported by: NWS Employee
Coordinates: 33.250, -116.380

Report of power outage to all of Borrego Springs around 4:05 pm, shortly after numerous lightning strikes in Palm Canyon and northwestern areas of Borrego Springs. Power remained off for 3+ hours and was restored between 7:00 pm and 7:30 pm. Several brief heavy downpours were also reported, with rainfall of 0.11 inch.

What these are

Lightning: A lightning strike that killed, injured or caused damage.
Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.
Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Wildfire: A fire burning in wildland vegetation, with its acreage and damage where known.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in California in 2022 Every state in 2022 This day in weather history Warnings in California, June 2022

Sources

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: 1024630, 1025515, 1024631, 1024635, 1024637, 1024638, 1024640, 1025527.