Alert archive / California / Flash Flood Warnings in 2024

Flash Flood Warning 44, NWS Phoenix, AZ

August 11, 2024Imperial County, California

NWS Phoenix, AZ issued this flash flood warning at Aug 11, 2024, 4:05 PM PDT for Imperial 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 counties it named.

The facts

Issued: Aug 11, 2024, 4:05 PM PDT (23:05 UTC)
Expired: Aug 11, 2024, 7:00 PM PDT
In force: 3 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Imperial County, CA

The radar

The Yuma radar (KYUX), 90 km from the middle of the area, began a volume at 23:05 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, 11.1 hours before the alert went out and 173 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: 1769 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: -34 m²/s²
0-3 km storm-relative helicity: -3 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

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 11, 1:35 PM PDT, 2 hours 30 minutes earlier.

Area forecast discussion, Aug 11, 1:35 PM PDT, 2 hours 30 minutes before

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In the hours before

Local storm report, Aug 11, 1:01 PM PDT, 3 hours 4 minutes before

Preliminary Local Storm Report
National Weather Service Phoenix AZ
101 PM MST Sun Aug 11 2024

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

0350 PM     Tstm Wnd Dmg     2 SW Wenden             33.80N 113.58W
08/10/2024                   La Paz             AZ   Utility Company

            ***Delayed report*** Report of one or more
            power poles down, causing a power outage to
            the area.

&&

SB

Special weather statement, Aug 11, 3:31 PM PDT, 34 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
331 PM PDT Sun Aug 11 2024

CAZ562-566-567-112315-
Imperial County West CA-Imperial County Southwest CA-
Imperial Valley CA-
331 PM PDT Sun Aug 11 2024

...STRONG THUNDERSTORMS WILL IMPACT SOUTHWESTERN IMPERIAL COUNTY
THROUGH 415 PM PDT...

At 331 PM PDT, Doppler radar was tracking a cluster of strong
thunderstorms near Ocotillo, moving west at 5 mph.

HAZARD...Wind gusts up to 40 mph.

SOURCE...Radar indicated.

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

Locations impacted include...
Plaster City, Ocotillo, Dixieland, and Coyote Wells.

This includes the following highways...
CA Interstate 8 near mile marker 1, and between mile markers 3 and
25.
CA Route 98 between mile markers 1 and 21.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3285 11610 3290 11588 3266 11566 3264 11570
      3263 11586 3262 11610 3277 11611
TIME...MOT...LOC 2231Z 082DEG 5KT 3273 11591

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

AY

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 5:06 PM PDT	Special Weather Statement	PSR	Pinal	24 min
Aug 10, 5:21 PM PDT	Severe Thunderstorm Warning	PSR	La Paz	39 min
Aug 10, 5:30 PM PDT	Special Weather Statement	PSR		45 min
Aug 10, 5:35 PM PDT	Severe Thunderstorm Warning	PSR	Gila, Maricopa	40 min
Aug 10, 5:37 PM PDT	Dust Storm Advisory	PSR	La Paz	53 min
Aug 10, 5:55 PM PDT	Areal Flood Advisory	PSR	La Paz	110 min
Aug 10, 6:15 PM PDT	Severe Thunderstorm Warning	PSR	Gila, Maricopa	45 min
Aug 10, 6:58 PM PDT	Severe Thunderstorm Warning	PSR	Maricopa	47 min
Aug 10, 7:16 PM PDT	Severe Thunderstorm Warning	PSR	Maricopa	44 min
Aug 10, 7:21 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Aug 10, 8:07 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Aug 11, 3:31 PM PDT	Special Weather Statement	PSR		44 min
Aug 10, 6:09 PM PDT	Areal Flood Advisory	PSR	Imperial, Riverside	3 hr
Aug 11, 3:44 PM PDT	Severe Thunderstorm Warning	PSR	Imperial	15 min
Aug 11, 4:13 PM PDT	Special Weather Statement	PSR	Imperial	47 min
Aug 11, 4:23 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Imperial	3 hr
Aug 11, 4:39 PM PDT	Dust Storm Advisory	PSR	Imperial	39 min
Aug 11, 4:52 PM PDT	Dust Storm Warning	PSR	Imperial	53 min
Aug 11, 4:56 PM PDT	Dust Storm Advisory	PSR	Imperial, Riverside	46 min

Nearby

Flash Flood Warnings in California, 2024 Every flash flood warning in 2024

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.