Alert archive / California / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 23, NWS Las Vegas, NV

August 11, 2026San Bernardino County, California

NWS Las Vegas, NV issued this severe thunderstorm warning at Aug 11, 2026, 5:42 PM PDT for San Bernardino County, California. It was in force for 48 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 11, 2026, 5:42 PM PDT (00:42 UTC)
Expired
Aug 11, 2026, 6:30 PM PDT
In force
48 min
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County San Bernardino County, CA

The radar

The Edwards AFB radar (KEYX), 129 km from the middle of the area, began a volume at 00:44 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 0.7 hours before the alert went out and 246 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, San Diego, CA at 00:00Z on 2026-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 00:00Z on 2026-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1843 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
8 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Las Vegas, NV wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 11, 4:15 PM PDT, 1 hour 27 minutes earlier. Its key messages:

  • * Daily afternoon to evening isolated thunderstorm chances will continue through the week, with the greatest chances over higher terrain and some storms spreading into adjacent valleys. Storm chances will increase in the mid week. * The high pressure is pushing eastward leading to cooling temperatures through the week.
Area forecast discussion, Aug 11, 4:15 PM PDT, 1 hour 27 minutes before
Area Forecast Discussion
National Weather Service Las Vegas NV
415 PM PDT Tue Aug 11 2026

.KEY MESSAGES...

* Daily afternoon to evening isolated thunderstorm chances will
  continue through the week, with the greatest chances over higher
  terrain and some storms spreading into adjacent valleys. Storm
  chances will increase in the mid week.

* The high pressure is pushing eastward leading to cooling
  temperatures through the week.

&&

.DISCUSSION...
Monsoonal moisture will remain in place through the end of the week
with the deepest moisture generally located over the southern half
of the forecast area with PWATs of 1.00-1.50" across Lincoln, Clark,
southern Nye, eastern San Bernardino, and Mohave counties. Areas to
the north and west will generally remain around 0.75-1.00". Storm
chances are expected to increase over most areas as we start to see
more influence from trough located offshore. This will increase
shear and some cooling aloft. This combined with decent instability
areawide should lead to a better coverage of storms at least through
Thursday afternoon. Storms will still be hit and miss, but overall
coverage will increase. With the high PWs, flash flooding will
remain a concern along with strong gusty outflow winds along with
small hail. By Thursday and especially Friday into the weekend, the
trough offshore will begin to push inland. This will bring a drier
southwest flow into the region ending shower and thunderstorm
chances from west to east with only the far eastern areas of the
forecast area seeing thunderstorm chances over the weekend.

While the exiting high pressure will allow for more convection
over the next few days, it will also call for a cooling trend
through the end of the work week. Heat risk will drop through the
week with all of the southern Great Basin and Mojave Desert seeing
only Minor or Moderate readings. Lows look to fall into the 70s and
80s while highs reduce into the 90s to lower 100s. Temperatures look
to rebound slightly into the weekend, but not significantly.

&&

.AVIATION...For Harry Reid...For the 00Z Forecast Package...Low (10-
20%) chance of an isolated storm making it into the vicinity, but
currently thinking activity will stay 10+ miles away on the high
terrain. Should any outflow reach the terminal, it should be from
the south/southwest or northwest. Light southwest winds settle in
overnight with a low chance (~20%) of late night or early morning
convection in the vicinity, but better odds exist Wednesday
afternoon. Cloud bases remain at or above 10kft as afternoon temps
flirt with 100F.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 00Z Forecast Package...Scattered convection
continues this afternoon across southeastern California, the
southern Great Basin, and Arizona Strip. Isolated activity possible
on the high terrain around Las Vegas, but should remain outside of
the valley. Showers and storms are expected to wane this evening,
though some late night or early morning redevelopment is possible in
southeastern Nevada and northwestern Arizona. Should this occur, it
may throw a wrench into the Wednesday afternoon forecast, but
otherwise expecting greater convective coverage across southern
Nevada and northwestern Arizona tomorrow.

&&

.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.

&&

DISCUSSION...Gorelow
AVIATION...Woods

For more forecast information...see us on our webpage:
https://weather.gov/lasvegas or follow us on Facebook and Twitter

The office that day

Everything else NWS Las Vegas, NV issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 12, 12:08 PM PDTSevere Thunderstorm WarningVEFClark52 min
Aug 12, 12:31 PM PDTSevere Thunderstorm WarningVEFClark44 min
Aug 12, 12:34 PM PDTAreal Flood AdvisoryVEFClark3 hr
Aug 12, 12:46 PM PDTSevere Thunderstorm WarningVEFClark44 min
Aug 12, 1:11 PM PDTSevere Thunderstorm WarningVEFClark49 min
Aug 12, 1:35 PM PDTAreal Flood AdvisoryVEFClark3 hr
Aug 12, 1:55 PM PDTFlash Flood Warning Considerable damage threatVEFClark3 hr
Aug 12, 2:00 PM PDTSevere Thunderstorm WarningVEFClark45 min
Aug 12, 2:21 PM PDTSevere Thunderstorm WarningVEFClark54 min
Aug 12, 1:24 AM PDTFlood WatchVEFMohave23 hr
Aug 12, 7:47 AM PDTAreal Flood AdvisoryVEFMohave5 hr
Aug 12, 8:24 AM PDTSevere Thunderstorm WarningVEFMohave51 min
Aug 12, 8:46 AM PDTFlash Flood Warning Considerable damage threatVEFMohave3 hr
Aug 12, 9:21 AM PDTAreal Flood AdvisoryVEFMohave3 hr
Aug 12, 11:10 AM PDTSevere Thunderstorm WarningVEFMohave50 min
Aug 12, 12:27 PM PDTAreal Flood AdvisoryVEFMohave3 hr
Aug 12, 2:53 PM PDTSevere Thunderstorm WarningVEFMohave52 min
Aug 12, 3:30 PM PDTAreal Flood AdvisoryVEFMohave30 min
Aug 12, 3:58 PM PDTSevere Thunderstorm WarningVEFMohave47 min
Aug 12, 4:00 PM PDTFlash Flood Warning Considerable damage threatVEFMohave4 hr
Aug 11, 6:26 PM PDTAreal Flood WarningVEFSan Bernardino3 hr
Aug 11, 6:46 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino3 hr
Aug 11, 6:54 PM PDTSevere Thunderstorm WarningVEFSan Bernardino51 min

Nearby

Severe Thunderstorm Warnings in California, 2026Every severe thunderstorm warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.