Alert archive / California / Flash Flood Warnings in 2026

Flash Flood Warning 36, NWS Las Vegas, NV

August 15, 2026San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Aug 15, 2026, 4:46 PM PDT for San Bernardino County, California. 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 15, 2026, 4:46 PM PDT (23:46 UTC)
Expired
Aug 15, 2026, 7:45 PM PDT
In force
3 hr
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), 171 km from the middle of the area, began a volume at 23:47 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 12:00Z, 11.8 hours before the alert went out and 217 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 12:00Z on 2026-08-15Temperature 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 12:00Z on 2026-08-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 square meters per square second.193958Sfc1 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
866 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
91 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

354 
WGUS55 KVEF 152346
FFWVEF
CAC071-160245-
/O.NEW.KVEF.FF.W.0036.260815T2346Z-260816T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
446 PM PDT Sat Aug 15 2026

The National Weather Service in Las Vegas has issued a

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

* Until 745 PM PDT.

* At 446 PM PDT, Doppler radar indicated thunderstorms producing
  heavy rain along Amboy Road in San Bernardino County. Between 0.5
  and 1.25 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...
  Mainly rural areas of San Bernardino County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3440 11600 3445 11593 3448 11578 3448 11567
      3447 11567 3447 11564 3443 11554 3439 11550
      3434 11547 3427 11547 3422 11552 3420 11558
      3420 11575 3423 11587 3427 11592 3427 11594
      3429 11595 3429 11598 3431 11602 3433 11603

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

$$

CO
2 follow-up statements
637 
WGUS75 KVEF 160035
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
535 PM PDT Sat Aug 15 2026

CAC071-160245-
/O.CON.KVEF.FF.W.0036.000000T0000Z-260816T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
535 PM PDT Sat Aug 15 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM PDT THIS
EVENING FOR SAN BERNARDINO COUNTY...

At 535 PM PDT, Thunderstorms are ongoing along Amboy road south of
Amboy. Radar estimates 1 to 2 inches of rain have fallen. Flash
Flooding remains a threat.

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...
  Mainly rural areas of San Bernardino County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3440 11600 3445 11593 3448 11578 3448 11567
      3447 11567 3447 11564 3443 11554 3439 11550
      3434 11547 3427 11547 3422 11552 3420 11558
      3420 11575 3423 11587 3427 11592 3427 11594
      3429 11595 3429 11598 3431 11602 3433 11603

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

$$

CO
447 
WGUS75 KVEF 160237
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
737 PM PDT Sat Aug 15 2026

CAC071-160247-
/O.EXP.KVEF.FF.W.0036.000000T0000Z-260816T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
737 PM PDT Sat Aug 15 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 745 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 3440 11600 3445 11593 3448 11578 3448 11567
      3447 11567 3447 11564 3443 11554 3439 11550
      3434 11547 3427 11547 3422 11552 3420 11558
      3420 11575 3423 11587 3427 11592 3427 11594
      3429 11595 3429 11598 3431 11602 3433 11603

$$

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 15, 3:53 PM PDT, 53 minutes earlier. Its key messages:

  • * Thunderstorm chances will continue today across portions of Lincoln, Clark and northern Mohave counties. Drier conditions are expected for the upcoming workweek. * Temperatures will steadily warm early this week, with areas of Moderate to Major HeatRisk developing across the Colorado River Valley, Death Valley, and parts of the Las Vegas Valley.
Area forecast discussion, Aug 15, 3:53 PM PDT, 53 minutes before
Area Forecast Discussion
National Weather Service Las Vegas NV
353 PM PDT Sat Aug 15 2026

.KEY MESSAGES...

* Thunderstorm chances will continue today across portions of
  Lincoln, Clark and northern Mohave counties. Drier conditions
  are expected for the upcoming workweek.

* Temperatures will steadily warm early this week, with areas of
  Moderate to Major HeatRisk developing across the Colorado River
  Valley, Death Valley, and parts of the Las Vegas Valley.

&&

.DISCUSSION...through next weekend.

One more day of scattered thunderstorm activity is expected
across the region this afternoon before more stable conditions
return Sunday and a gradual drying out develops next week. This
mornings convective allowing guidance continues to favor western
Clark and Lincoln Counties, and central San Bernardino Counties
for the most robust activity. This mornings 18z VEF sounding shows
a trend towards less instability today compared to Friday, with a
slight warming of 500mb temps, and drier air aloft above 600mb.
Southwesterly shear has also weakened slightly compared to 24
hours ago, but remains elevated for mid-August, with about 20-30
knots of bulk shear. These subtle changes should result in a
modest decrease in hail risk and overall storm coverage, but
continued potential for localized strong wind gusts and pockets of
heavy rain.

While instability will wane further on Sunday, some mid-level
moisture from Tropical Depression Hernan will become entrained in
the southwesterly flow resulting in widespread mid-level clouds
and some low shower/sprinkle chances through the day across the
eastern Mojave Desert, southern Nevada, and northwest Arizona.

By early next week, high pressure will build across AZ/NM before
expanding westward into eastern NV/Utah by the end of the week.
This will result in increase HeatRisk across the region and a
pause in the monsoonal thunderstorm activity that has been
prevalent the past few days. Surface moisture will remain
somewhat elevated keeping overnight low temps warm but moderating
afternoon highs slightly. Nonetheless, a return of 110+ temps is
expected across the Lower Colorado River Valley and Death Valley.
By next weekend, there are hints a southerly flow will return and
monsoonal thunderstorm activity may return - though uncertainty
remains high.

&&

.AVIATION...For Harry Reid...For the 00Z Forecast Package...Storm
activity in the Las Vegas Valley within the vicinity of the
terminal cannot be ruled out through around 02Z. Storms may
produce gusty and erratic winds along with heavy rainfall and
ceilings down to around 8kft AGL. Winds should favor a
southwesterly direction overnight with speeds of less than 10
knots. For tomorrow, showers may move through the region in the
morning and early afternoon. Southeasterly winds develop later in
the afternoon. Temperatures will remain below 100 degrees today,
and may reach 100 degrees around 00Z tomorrow afternoon.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 00Z Forecast Package...Convection will continue
across parts of the Mojave Desert, southern Great Basin, and
northwestern Arizona through sunset. Gusty and erratic winds and
heavy rainfall are the primary concerns with these storms. Rain
showers move through the region tomorrow morning, possibly reaching
terminals in the Las Vegas Valley and Colorado River Valley.
Sustained wind speeds tomorrow should be around 10 knots or less.

&&

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

&&

DISCUSSION...Outler
AVIATION...Meltzer

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 15, 1:59 PM PDT, 2 hours 47 minutes before
Preliminary Local Storm Report
National Weather Service Las Vegas NV
159 PM PDT Sat Aug 15 2026

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

0550 PM     Flash Flood      5 NE Dolan Springs      35.66N 114.22W
08/14/2026                   Mohave             AZ   Public

            Photo shows an SUV buried to the front
            bumper by mud and debris from flooding.

&&

MS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 14, 7:41 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 14, 10:30 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 15, 12:45 PM PDTSevere Thunderstorm WarningVEFSan Bernardino45 min
Aug 15, 1:08 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 15, 3:44 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino3 hr
Aug 15, 4:49 PM PDTSevere Thunderstorm WarningVEFSan Bernardino41 min

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.