Alert archive / California / Flash Flood Warnings in 2021
Flash Flood Warning 15, NWS San Diego, CA
NWS San Diego, CA issued this flash flood warning at Sep 9, 2021, 4:33 PM PDT for Riverside County, California. It was in force for 88 min. 2 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Sep 9, 2021, 4:33 PM PDT (23:33 UTC)
- Expired
- Sep 9, 2021, 6:01 PM PDT
- In force
- 88 min
- Issued by
- NWS San Diego, CA
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
County Riverside County, CA
The radar
The Santa Ana Mts radar (KSOX), 74 km from the middle of the area, began a volume at 23:35 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Sep 9, 4:58 PM PDT | FLOOD | 1 E Banning, CA | FLOODING REPORTED RAMSEY ST ON RAMP AND I-10 EAST. |
| Sep 9, 5:00 PM PDT | HEAVY RAIN 1.1 | 3 Ne Mt San Jacinto, CA | LOWER SNOW CREEK RECEIVED 1.10 INCHES IN 1 HOUR AND 0.39 INCHES IN 15 MINUTES FROM THUNDERSTORM. RIVERSIDE COUNTY FLOOD CONTROL. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
San Diego, CA (KNKX), launched 12:00Z, 11.6 hours before the alert went out and 123 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.
- Mixed-layer CAPE
- 15 J/kg
- Mixed-layer CIN
- -787 J/kg
- Mixed-layer LCL
- 1710 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 44 m²/s²
- 0-3 km storm-relative helicity
- 112 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
716
WGUS56 KSGX 092333
FFWSGX
CAC065-100245-
/O.NEW.KSGX.FF.W.0015.210909T2333Z-210910T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Diego CA
433 PM PDT Thu Sep 9 2021
The National Weather Service in San Diego has issued a
* Flash Flood Warning for...
Riverside County in southern California...
* Until 745 PM PDT.
* At 433 PM PDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 3 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.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
* Some locations that will experience flash flooding include...
Northwestern Palm Springs, Hwy 243 Between Banning And Idyllwild,
Idyllwild-Pine Cove, Mt San Jacinto State Park, Hemet, San
Jacinto, Beaumont, Banning, Cabazon, Hwy 74 Between Hemet And
Mountain Center, Valle Vista, Mountain Center, Whitewater,
Calimesa, Saboba Indian Reservation and Morongo Indian Reservation.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3395 11702 3397 11667 3373 11659 3370 11689
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
Brotherton1 follow-up statement
370 WGUS76 KSGX 100101 FFSSGX Flash Flood Statement National Weather Service San Diego CA 601 PM PDT Thu Sep 9 2021 CAC065-100111- /O.CAN.KSGX.FF.W.0015.000000T0000Z-210910T0245Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Riverside CA- 601 PM PDT Thu Sep 9 2021 ...FLASH FLOOD WARNING IS CANCELLED FOR RIVERSIDE COUNTY... The heavy rain has ended. Flooding is no longer expected to pose a threat. Please continue to heed remaining road closures. LAT...LON 3395 11702 3397 11667 3373 11659 3370 11689 $$ Brotherton
The office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 9, 12:40 PM PDT | Special Weather Statement | SGX | 50 min | |
| Sep 9, 1:05 PM PDT | Severe Thunderstorm Warning | SGX | San Bernardino | 40 min |
| Sep 9, 1:19 PM PDT | Severe Thunderstorm Warning | SGX | San Bernardino | 22 min |
| Sep 9, 2:12 PM PDT | Areal Flood Advisory | SGX | San Diego | 3 hr |
| Sep 9, 2:34 PM PDT | Flash Flood Warning | SGX | San Bernardino | 3 hr |
| Sep 9, 2:54 PM PDT | Severe Thunderstorm Warning | SGX | San Bernardino | 66 min |
| Sep 9, 3:10 PM PDT | Severe Thunderstorm Warning | SGX | Riverside, San Bernardino | 50 min |
| Sep 9, 3:25 PM PDT | Special Weather Statement | SGX | 50 min | |
| Sep 9, 3:29 PM PDT | Flash Flood Warning | SGX | Riverside, San Bernardino | 2 hr |
| Sep 9, 3:46 PM PDT | Areal Flood Advisory | SGX | Riverside | 3 hr |
| Sep 9, 4:35 PM PDT | Severe Thunderstorm Warning | SGX | Riverside, San Bernardino | 55 min |
Nearby
Flash Flood Warnings in California, 2021Every flash flood warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.