Alert archive / California / Flash Flood Warnings in 2026

Flash Flood Warning 23, NWS Las Vegas, NV

August 12, 2026San Bernardino County, California; Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 12, 2026, 1:55 PM PDT for San Bernardino County, California; Clark County, Nevada. It was in force for 3 hr. 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 12, 2026, 1:55 PM PDT (20:55 UTC)
Expired
Aug 12, 2026, 5:00 PM PDT
In force
3 hr
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties San Bernardino County, CA, Clark County, NV

The radar

The Las Vegas radar (KESX), 37 km from the middle of the area, began a volume at 20:55 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

Las Vegas, NV (KVEF), launched 12:00Z, 8.9 hours before the alert went out and 131 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, Las Vegas, NV at 12:00Z on 2026-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 281 joules per kilogram.LCLLFCEL10008507005003002001001 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, Las Vegas, NV at 12:00Z on 2026-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -78 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
281 J/kg
Mixed-layer CIN
-140 J/kg
Mixed-layer LCL
2608 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
-78 m²/s²
0-3 km storm-relative helicity
3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

404 
WGUS55 KVEF 122055
FFWVEF
CAC071-NVC003-130000-
/O.NEW.KVEF.FF.W.0023.260812T2055Z-260813T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
155 PM PDT Wed Aug 12 2026

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  San Bernardino County in southern California...
  South Central Clark County in southern Nevada...

* Until 500 PM PDT.

* At 155 PM PDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to 1.5 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...
  Searchlight, Cal-Nev-Ari, Cottonwood Cove Campground and Cottonwood
  Cove.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3553 11511 3555 11466 3553 11466 3551 11468
      3549 11468 3548 11467 3546 11467 3545 11466
      3544 11466 3541 11463 3534 11460 3531 11460
      3515 11480 3500 11479 3502 11490

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

$$

MW
2 follow-up statements
456 
WGUS75 KVEF 122221
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
321 PM PDT Wed Aug 12 2026

CAC071-NVC003-130000-
/O.CON.KVEF.FF.W.0023.000000T0000Z-260813T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-Clark NV-
321 PM PDT Wed Aug 12 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 5 PM PDT THIS
AFTERNOON FOR SAN BERNARDINO AND SOUTH CENTRAL CLARK COUNTIES...

At 321 PM PDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Up to 1.5 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...
  Searchlight, Cal-Nev-Ari, Cottonwood Cove Campground and Cottonwood
  Cove.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3553 11511 3555 11466 3553 11466 3551 11468
      3549 11468 3548 11467 3546 11467 3545 11466
      3544 11466 3541 11463 3534 11460 3531 11460
      3515 11480 3500 11479 3502 11490

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

$$

MW
396 
WGUS75 KVEF 122358
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
458 PM PDT Wed Aug 12 2026

CAC071-NVC003-130008-
/O.EXP.KVEF.FF.W.0023.000000T0000Z-260813T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-Clark NV-
458 PM PDT Wed Aug 12 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 5 PM PDT THIS AFTERNOON FOR SAN
BERNARDINO AND SOUTH CENTRAL CLARK COUNTIES...

Flood waters have receded. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.

A Flood Watch remains in effect until 1200 AM PDT Thursday for a
portion of northwest Arizona.

&&

LAT...LON 3553 11511 3555 11466 3553 11466 3551 11468
      3549 11468 3548 11467 3546 11467 3545 11466
      3544 11466 3541 11463 3534 11460 3531 11460
      3515 11480 3500 11479 3502 11490

$$

JCS

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 12, 10:43 AM PDT, 3 hours 12 minutes earlier. Its key messages:

  • * Wednesday afternoon offers widespread chances for storms with an increased risk for flooding in Mohave County AZ, with a Flash Flood Watch issued from noon through midnight. * Daily afternoon to evening isolated thunderstorm chances will continue through the late week, with the greatest chances over higher terrain and some storms spreading into adjacent valleys. * Temperatures continue to cool into the weekend with a slight rebound in temperatures over the weekend and into the next work week.
Area forecast discussion, Aug 12, 10:43 AM PDT, 3 hours 12 minutes before
Area Forecast Discussion
National Weather Service Las Vegas NV
1043 AM PDT Wed Aug 12 2026

.KEY MESSAGES...

* Wednesday afternoon offers widespread chances for storms with
  an increased risk for flooding in Mohave County AZ, with a Flash
  Flood Watch issued from noon through midnight.

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

* Temperatures continue to cool into the weekend with a slight
  rebound in temperatures over the weekend and into the next work
  week.

&&

.DISCUSSION...

Lingering showers continue to pass through the region, but these
overnight precip chances don't look very impactful. The continued
push of monsoonal moisture will offer some of the best and most
widespread chances for storms of the forecast this afternoon. The
best chances will be along the favored higher terrain, but the
environment looks to allow for much more of those storms to filter
into the valleys across the region. Additionally, shorter-term
models are keeping the storm chances later into the night compared
to previous days, with things not completely settling down until
the late night. The spread of the storms and the amount to
moisture aloft will increase concerns for flooding for Clark Co
NV and Mojave Co AZ, with WPC upgrading those areas to a 15 to 25%
risk of Excessive Rainfall. Taking into consideration the more
consistent chances for storms, as well as terrain and flood prone
environments affected, a Flash Flood Watch has been issued for
Mohave County AZ from noon through midnight.

A slight pattern shift will reduce Thursday's storm chances, but
will still offer a good environment for afternoon and evening
storms. While widespread flooding looks less likely, localized
flooding will still be a threat, along with thunderstorm gusts and
lightning. Friday's storm chances will be much more spotty and
look to dissipate earlier than previous days. Conditions stabilize
into the weekend as a high pressure tilts back into the region.

The overall cooling trend continues through the late 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 18Z Forecast Package...Light
and variable winds becoming southerly by late morning. Convection is
expected to develop Wednesday afternoon with more coverage than
previous days. 30%-40% chance of thunderstorms at the terminals
which could result in brief heavy rain, visibility under 5SM, sudden
gusty winds, and CIGs below 8000ft. Outside of convection, south to
southeast winds around 12KT with occasional gusts over 20KT are
expected. Light and variable winds will develop toward sunset. VFR
conditions with SCT-BKN clouds over 10kft are expected overnight. A
20-30% chance of thunderstorms on Thursday afternoon with similar
CIGs and VSBYs.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...The initial round of
showers and thunderstorms may shift in eastern Mohave County will
diminish by early afternoon. Convection will develop again Wednesday
afternoon across much of the region. Any storms could produce
lightning, heavy rain, sudden gusty winds, and CIGs below 8000ft.
Outside of convective influences, south to southwest winds around 10-
15KT will develop Wednesday afternoon. Wind and convection will
diminish after sunset Wednesday. Although coverage will be less,
thunderstorms will develop again on Thursday afternoon.

&&

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

&&

DISCUSSION...Murdock
AVIATION...Czyzyk

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

In the hours before

Local storm report, Aug 12, 9:32 AM PDT, 4 hours 23 minutes before
Preliminary Local Storm Report
National Weather Service Las Vegas NV
932 AM PDT Wed Aug 12 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0811 AM     Tstm Wnd Gst     5 E New Kingman-Butler  35.26N 113.94W
08/12/2026  M67 MPH          Mohave             AZ   ASOS

            Kingman Airport (KIGM) recorded 60+ mph
            gusts from 0811-0824.

&&

DB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 5:42 PM PDTSevere Thunderstorm WarningVEFSan Bernardino48 min
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
Aug 12, 2:53 PM PDTSevere Thunderstorm WarningVEFSan Bernardino52 min
Aug 12, 3:30 PM PDTAreal Flood AdvisoryVEFSan Bernardino30 min
Aug 12, 3:58 PM PDTSevere Thunderstorm WarningVEFSan Bernardino47 min
Aug 12, 4:00 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino4 hr
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, 2:00 PM PDTSevere Thunderstorm WarningVEFClark45 min
Aug 12, 2:21 PM PDTSevere Thunderstorm WarningVEFClark54 min

Nearby

Flash Flood Warnings in California, 2026Flash Flood Warnings in Nevada, 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.