Alert archive / California / Flash Flood Warnings in 2026

Flash Flood Warning 16, NWS Las Vegas, NV

August 10, 2026San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Aug 10, 2026, 7:22 PM PDT for San Bernardino County, California. It was in force for 113 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 10, 2026, 7:22 PM PDT (02:22 UTC)
Expired
Aug 10, 2026, 9:15 PM PDT
In force
113 min
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County San Bernardino County, CA

The radar

The Las Vegas radar (KESX), 153 km from the middle of the area, began a volume at 02:22 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 2.4 hours before the alert went out and 234 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 2026-08-11Temperature 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 2026-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 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
2119 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

929 
WGUS55 KVEF 110222
FFWVEF
CAC071-110415-
/O.NEW.KVEF.FF.W.0016.260811T0222Z-260811T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
722 PM PDT Mon Aug 10 2026

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  San Bernardino County in southern California...

* Until 915 PM PDT.

* At 722 PM PDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to 2 inches of rain have
  fallen. Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms producing
           flash flooding.

  SOURCE...Radar indicated.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  National Trails Highway between Ludlow and Amboy, Amboy, Amboy Road

This includes Interstate 40 in California between mile markers 50 and
58.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 3474 11610 3473 11620 3469 11609 3457 11596
      3453 11582 3446 11573 3457 11571 3458 11579
      3463 11595 3468 11600 3472 11602

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Stessman
2 follow-up statements
124 
WGUS75 KVEF 110304
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
804 PM PDT Mon Aug 10 2026

CAC071-110415-
/O.CON.KVEF.FF.W.0016.000000T0000Z-260811T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
804 PM PDT Mon Aug 10 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM PDT THIS
EVENING FOR SAN BERNARDINO COUNTY...

At 804 PM PDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Up to 2 inches of rain have fallen.
Flash flooding is ongoing or expected to begin shortly.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar indicated.

IMPACT...Life threatening flash flooding of creeks and streams, urban
         areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  National Trails Highway between Ludlow and Amboy, Amboy, Amboy Road

This includes Interstate 40 in California between mile markers 50 and
58.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 3474 11610 3473 11620 3469 11609 3457 11596
      3453 11582 3446 11573 3457 11571 3458 11579
      3463 11595 3468 11600 3472 11602

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Stessman
867 
WGUS75 KVEF 110406
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
906 PM PDT Mon Aug 10 2026

CAC071-110416-
/O.EXP.KVEF.FF.W.0016.000000T0000Z-260811T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
906 PM PDT Mon Aug 10 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 915 PM PDT THIS EVENING FOR SAN
BERNARDINO COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.

&&

LAT...LON 3474 11610 3473 11620 3469 11609 3457 11596
      3453 11582 3446 11573 3457 11571 3458 11579
      3463 11595 3468 11600 3472 11602

$$

Stessman

What forecasters said that day

The local office's own words before this flash flood 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 flash flood warning went out at Aug 10, 3:38 PM PDT, 3 hours 44 minutes earlier. Its key messages:

  • * Dangerous heat will continue today, with widespread Moderate to Major HeatRisk driven by well above normal temperatures and increased humidity. * 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 pushes east leading to cooling temperatures through the week.
Area forecast discussion, Aug 10, 3:38 PM PDT, 3 hours 44 minutes before
Area Forecast Discussion
National Weather Service Las Vegas NV
338 PM PDT Mon Aug 10 2026

.KEY MESSAGES...

* Dangerous heat will continue today, with widespread Moderate to
  Major HeatRisk driven by well above normal temperatures and
  increased humidity.

* 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 pushes east leading to cooling temperatures
  through the week.

&&

.DISCUSSION...Today through next weekend.

Today is expected to be the last day of Extreme Heat as the high
pressure responsible for the excessive temperatures shifts east.
Expect temperatures to peak above 100 degrees in the Owens Valley,
near 110 degrees for most of the Mojave Desert, and a few localized
areas reaching 115 around the hottest portions of the region. The
Extreme Heat Warning lasts through this evening. The one caveat is
the cloud cover over Clark and northern Mohave counties associated
with two separate MCVs that were generated over southern Arizona
last night. This may help to keep temperatures down a bit across
those areas.

Even though the high shifts east, we will continue to see plenty of
monsoonal moisture over the region for much of the the week. The
aforementioned MCVs are both rotating northward across Clark and
northern Mohave counties with storms forming along the northern and
western edges. This trend is expected to continue through the
afternoon as these MCVs move north. Storms may be more delayed in
the wake of these MCVs due to more subsidence, but with enough
afternoon heating we may up seeing storms develop later this
afternoon. A weak, cut off low will also help to push additional
moisture into the area Tuesday and Wednesday leading to good chances
for isolated to scattered storms each afternoon and evening through
the late week. Another pattern change will reduce storm chances into
the weekend, but doesn't completely erase storms from the late-term
forecast with storms mainly confined to the eastern half of the CWA
by the weekend.

The mid-week moisture push and the exiting high pressure will lead
to widespread cooling. Heat risk will reduce through the week as
temperatures begin to reduce closer to average for this time of
year. Lows look to fall into the 70s and 80s while highs reduce
into the 90s to lower 100s.

&&

.AVIATION...For Harry Reid...For the 00Z Forecast Package...
South to southwest winds will prevail late afternoon and evening,
but some variability will occur due to thunderstorms in the area.
Thunderstorms will persist into this evening before diminishing
overnight. Outside of any thunderstorm influence, winds will
generally remain less than 10 knots. The probability of
thunderstorms within the Las Vegas Valley is generally around 20
percent, but confidence is too low to include in the TAF.
Temperatures will exceed 100 degrees through 05Z.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 00Z Forecast Package...Isolated showers and
thunderstorms into this evening with locally heavy rain and gusty
and erratic outflow winds. Storms are expected to dissipate by 04Z
with SCT clouds around 10-12kft. Outside of any thunderstorm wind
impacts, winds will generally remain less than 10 knots.

&&

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

&&

DISCUSSION/AVIATION...Gorelow

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 10, 5:02 PM PDTSevere Thunderstorm WarningVEFSan Bernardino43 min
Aug 10, 5:21 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 10, 6:05 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 10, 6:30 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 10, 6:52 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 11, 2:14 PM PDTSevere Thunderstorm WarningVEFSan Bernardino46 min
Aug 11, 3:08 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 11, 3:26 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino3 hr
Aug 11, 3:36 PM PDTSevere Thunderstorm WarningVEFSan Bernardino39 min
Aug 11, 3:50 PM PDTSevere Thunderstorm Warning Considerable damage threatVEFSan Bernardino40 min
Aug 11, 4:12 PM PDTSevere Thunderstorm Warning Considerable damage threatVEFSan Bernardino48 min
Aug 11, 4:18 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino3 hr
Aug 11, 4:24 PM PDTFlash Flood Warning Considerable damage threatVEFInyo3 hr
Aug 11, 4:42 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino3 hr

Nearby

Flash Flood Warnings in California, 2026Every flash flood 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.