Alert archive / California / Flash Flood Warnings in 2024

Flash Flood Warning 24, NWS San Diego, CA

September 8, 2024San Bernardino County, California

NWS San Diego, CA issued this flash flood warning at Sep 8, 2024, 1:40 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 counties it named.

The facts

Issued
Sep 8, 2024, 1:40 PM PDT (20:40 UTC)
Expired
Sep 8, 2024, 4:45 PM PDT
In force
3 hr
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County San Bernardino County, CA

The radar

The Edwards AFB radar (KEYX), 129 km from the middle of the area, began a volume at 20:40 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

Las Vegas, NV (KVEF), launched 12:00Z, 8.7 hours before the alert went out and 180 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 2024-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 22 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 2024-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 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
22 J/kg
Mixed-layer CIN
-378 J/kg
Mixed-layer LCL
3428 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
3 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 San Diego, CA wrote its last area forecast discussion before this flash flood warning went out at Sep 8, 9:34 AM PDT, 4 hours 6 minutes earlier.

Area forecast discussion, Sep 8, 9:34 AM PDT, 4 hours 6 minutes before
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In the hours before

Special weather statement, Sep 8, 1:04 PM PDT, 36 minutes before
Special Weather Statement
National Weather Service San Diego CA
104 PM PDT Sun Sep 8 2024

CAZ048-057-082045-
San Bernardino and Riverside County Valleys-The Inland Empire CA-
Santa Ana Mountains and Foothills CA-
104 PM PDT Sun Sep 8 2024

...A STRONG THUNDERSTORM WILL IMPACT RIVERSIDE AND EAST CENTRAL
ORANGE COUNTIES THROUGH 145 PM PDT...

At 104 PM PDT, Doppler radar was tracking a strong thunderstorm near
Lake Elsinore. This thunderstorm was nearly stationary.

HAZARD...Wind gusts up to 50 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Temecula, Lake Elsinore, Murrieta, Perris, Sun City, Menifee, Ortega
Highway, Wildomar, Canyon Lake, Romoland, Lakeland Village, Quail
Valley, Santa Rosa Plateau, and Sedco Hills.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3351 11742 3369 11745 3376 11717 3349 11713
TIME...MOT...LOC 2004Z 263DEG 4KT 3361 11735

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 MPH

Munyan
Special weather statement, Sep 8, 1:14 PM PDT, 26 minutes before
Special Weather Statement
National Weather Service San Diego CA
114 PM PDT Sun Sep 8 2024

CAZ048-056-082100-
Riverside County Mountains CA-
San Bernardino and Riverside County Valleys-The Inland Empire CA-
114 PM PDT Sun Sep 8 2024

...A STRONG THUNDERSTORM WILL IMPACT RIVERSIDE COUNTY THROUGH 200 PM
PDT...

At 114 PM PDT, Doppler radar was tracking a strong thunderstorm 7
miles south of Hemet. This thunderstorm was nearly stationary.

HAZARD...Wind gusts up to 50 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Temecula, Hemet, East Hemet, Hwy 74 Between Hemet And Mountain
Center, Valle Vista, Aguanga, Sage, Winchester, and Lake Skinner
Recreation Area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3353 11691 3358 11709 3378 11708 3371 11678
TIME...MOT...LOC 2014Z 197DEG 3KT 3363 11699

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 MPH

Munyan

The office that day

Everything else NWS San Diego, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 8, 11:56 AM PDTAreal Flood AdvisorySGXSan Bernardino119 min
Sep 8, 12:53 PM PDTAreal Flood AdvisorySGXRiverside2 hr
Sep 8, 1:00 PM PDTAreal Flood AdvisorySGXSan Bernardino119 min
Sep 8, 1:04 PM PDTSpecial Weather StatementSGXOrange41 min
Sep 8, 1:09 PM PDTSevere Thunderstorm WarningSGXSan Bernardino51 min
Sep 8, 1:14 PM PDTSpecial Weather StatementSGX46 min
Sep 8, 1:27 PM PDTSevere Thunderstorm WarningSGXSan Bernardino6 min
Sep 8, 1:27 PM PDTSevere Thunderstorm WarningSGXSan Bernardino63 min
Sep 8, 1:34 PM PDTSevere Thunderstorm WarningSGXRiverside41 min
Sep 8, 1:55 PM PDTSpecial Weather StatementSGX50 min
Sep 8, 2:01 PM PDTAreal Flood AdvisorySGXSan Diego2 hr
Sep 8, 2:04 PM PDTSevere Thunderstorm WarningSGXRiverside, San Diego56 min
Sep 8, 2:12 PM PDTAreal Flood AdvisorySGXRiverside, San Diego2 hr
Sep 8, 2:13 PM PDTFlash Flood Warning Considerable damage threatSGXSan Bernardino3 hr
Sep 8, 2:15 PM PDTAreal Flood AdvisorySGXRiverside2 hr
Sep 8, 2:24 PM PDTSevere Thunderstorm WarningSGXRiverside18 min
Sep 8, 2:27 PM PDTSevere Thunderstorm WarningSGXRiverside, San Bernardino48 min
Sep 8, 2:43 PM PDTFlash Flood Warning Considerable damage threatSGXSan Bernardino3 hr
Sep 8, 2:54 PM PDTAreal Flood AdvisorySGXSan Bernardino118 min
Sep 8, 2:54 PM PDTFlash Flood Warning Considerable damage threatSGXRiverside, San Bernardino3 hr
Sep 8, 2:58 PM PDTSevere Thunderstorm WarningSGXRiverside, San Diego47 min
Sep 8, 3:01 PM PDTFlash Flood Warning Considerable damage threatSGXRiverside3 hr
Sep 8, 3:10 PM PDTSevere Thunderstorm WarningSGXRiverside, San Bernardino50 min
Sep 8, 3:28 PM PDTFlash Flood Warning Considerable damage threatSGXRiverside, San Bernardino3 hr
Sep 8, 3:45 PM PDTSpecial Weather StatementSGXOrange45 min
Sep 8, 3:52 PM PDTSpecial Weather StatementSGX38 min
Sep 8, 3:54 PM PDTFlash Flood Warning Considerable damage threatSGXRiverside3 hr
Sep 8, 3:59 PM PDTSpecial Weather StatementSGX46 min
Sep 8, 4:07 PM PDTSpecial Weather StatementSGXOrange38 min
Sep 8, 4:15 PM PDTSpecial Weather StatementSGXOrange45 min
Sep 8, 4:22 PM PDTSevere Thunderstorm WarningSGXRiverside53 min
Sep 8, 4:25 PM PDTSevere Thunderstorm WarningSGXSan Diego35 min
Sep 8, 4:37 PM PDTAreal Flood AdvisorySGXRiverside2 hr
Sep 8, 4:50 PM PDTSevere Thunderstorm WarningSGXRiverside55 min

Nearby

Flash Flood Warnings in California, 2024Every 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.