Alert archive / California / Flash Flood Warnings in 2025

Flash Flood Warning 24, NWS Phoenix, AZ

August 25, 2025Riverside County, San Bernardino County, California

NWS Phoenix, AZ issued this flash flood warning at Aug 25, 2025, 3:40 PM PDT for Riverside County, San Bernardino County, California. It was in force for 4 hr. 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 25, 2025, 3:40 PM PDT (22:40 UTC)
Expired: Aug 25, 2025, 7:45 PM PDT
In force: 4 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Riverside County, CA, San Bernardino County, CA

The radar

The Santa Ana Mts radar (KSOX), 152 km from the middle of the area, began a volume at 22:41 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 12:00Z, 10.7 hours before the alert went out and 195 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1772 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 9 m²/s²
0-3 km storm-relative helicity: 49 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 flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Phoenix, AZ wrote its last area forecast discussion before this flash flood warning went out at Aug 25, 1:52 PM PDT, 1 hour 48 minutes earlier.

Area forecast discussion, Aug 25, 1:52 PM PDT, 1 hour 48 minutes before

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In the hours before

Special weather statement, Aug 25, 2:23 PM PDT, 1 hour 17 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
223 PM MST Mon Aug 25 2025

AZZ532-CAZ565-569-252215-
Yuma AZ-Imperial County Southeast CA-Palo Verde Valley CA-
223 PM MST Mon Aug 25 2025

...A STRONG THUNDERSTORM WILL IMPACT WESTERN YUMA AND SOUTHEASTERN
IMPERIAL COUNTIES THROUGH 315 PM MST/315 PM PDT/...

At 222 PM MST/222 PM PDT/, Doppler radar was tracking a strong
thunderstorm 7 miles north of Winterhaven, or 15 miles southwest of
Martinez Lake, moving southwest at 10 mph.

Strong, gusty winds will be capable of producing areas of blowing
dust with reduced visibilities down to one to two miles!

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Winterhaven and Andrade.

This includes CA Interstate 8 between mile markers 84 and 95.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3271 11473 3272 11472 3272 11476 3281 11493
      3297 11468 3287 11452 3268 11468
TIME...MOT...LOC 2122Z 043DEG 10KT 3284 11469

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

INS

Local storm report, Aug 25, 2:48 PM PDT, 52 minutes before

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Special weather statement, Aug 25, 2:49 PM PDT, 51 minutes before

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Special weather statement, Aug 25, 3:11 PM PDT, 29 minutes before

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Local storm report, Aug 25, 3:26 PM PDT, 14 minutes before

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The office that day

Everything else NWS Phoenix, AZ issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 24, 7:21 PM PDT	Special Weather Statement	PSR	La Paz	39 min
Aug 25, 12:50 AM PDT	Special Weather Statement	PSR		25 min
Aug 25, 1:26 AM PDT	Special Weather Statement	PSR	Maricopa	49 min
Aug 25, 2:00 AM PDT	Blowing Dust Advisory	PSR	Maricopa, Pinal	17 hr
Aug 25, 2:00 AM PDT	Flood Watch	PSR	La Paz, Maricopa, Yuma	19 hr
Aug 25, 3:23 AM PDT	Special Weather Statement	PSR	Yuma	52 min
Aug 25, 2:23 PM PDT	Special Weather Statement	PSR		52 min
Aug 25, 2:49 PM PDT	Special Weather Statement	PSR		41 min
Aug 25, 3:11 PM PDT	Special Weather Statement	PSR		49 min
Aug 25, 3:32 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Yuma	4 hr
Aug 25, 3:50 PM PDT	Dust Storm Warning	PSR	Maricopa, Pinal	55 min
Aug 25, 3:56 PM PDT	Dust Storm Advisory	PSR	Maricopa	49 min
Aug 25, 4:38 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Yuma	4 hr
Aug 25, 4:41 PM PDT	Dust Storm Warning	PSR	Maricopa, Pinal	64 min
Aug 25, 4:59 PM PDT	Special Weather Statement	PSR	Yuma	31 min
Aug 25, 6:57 AM PDT	Flash Flood Warning Considerable damage threat	PSR	Riverside	3 hr
Aug 25, 7:56 AM PDT	Areal Flood Advisory	PSR	Riverside	2 hr
Aug 25, 1:23 PM PDT	Severe Thunderstorm Warning	PSR	Imperial	52 min
Aug 25, 2:08 PM PDT	Severe Thunderstorm Warning	PSR	Imperial	52 min
Aug 25, 2:11 PM PDT	Severe Thunderstorm Warning	PSR	Imperial	49 min
Aug 25, 2:37 PM PDT	Severe Thunderstorm Warning	PSR	Imperial	38 min
Aug 25, 2:42 PM PDT	Severe Thunderstorm Warning	PSR	Imperial	33 min
Aug 25, 2:55 PM PDT	Areal Flood Advisory	PSR	Imperial	4 hr
Aug 25, 3:00 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Imperial	4 hr
Aug 25, 3:10 PM PDT	Dust Storm Advisory	PSR	Imperial	65 min
Aug 25, 3:12 PM PDT	Severe Thunderstorm Warning	PSR	Imperial	48 min
Aug 25, 3:21 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Imperial	4 hr
Aug 25, 3:25 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Imperial	4 hr
Aug 25, 3:57 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Imperial	4 hr
Aug 25, 4:15 PM PDT	Special Weather Statement	PSR	Riverside	45 min

Nearby

Flash Flood Warnings in California, 2025 Every flash flood warning in 2025

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.