Alert archive / California / Flash Flood Warnings in 2021
Flash Flood Warning 12, NWS San Diego, CA
NWS San Diego, CA issued this flash flood warning at Aug 31, 2021, 5:44 PM PDT for Riverside County, San Diego County, California. It was in force for 96 min. 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 31, 2021, 5:44 PM PDT (00:44 UTC)
- Expired
- Aug 31, 2021, 7:20 PM PDT
- In force
- 96 min
- Issued by
- NWS San Diego, CA
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
Counties Riverside County, CA, San Diego County, CA
The radar
The San Diego radar (KNKX), 112 km from the middle of the area, began a volume at 00:46 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 00:00Z, 0.7 hours before the alert went out and 132 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 853 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- -77 m²/s²
- 0-3 km storm-relative helicity
- -65 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
882
WGUS56 KSGX 010044
FFWSGX
CAC065-073-010345-
/O.NEW.KSGX.FF.W.0012.210901T0044Z-210901T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Diego CA
544 PM PDT Tue Aug 31 2021
The National Weather Service in San Diego has issued a
* Flash Flood Warning for...
Riverside County in southern California...
Northeastern San Diego County in southwestern California...
* Until 845 PM PDT.
* At 544 PM PDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area with the heaviest rain occurring
along Highway 86 just west of Desert Shores where flash flooding
is likely. Additional thunderstorms with heavy rain are occurring
over Chiriaco Summit. Water from this will flow southwest across
Box Canyon. Between 0.5 and 1 inch of rain has fallen. Additional
rainfall amounts of 0.5 to 1 inch are possible in the warned area.
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...
Box Canyon, Coachella, Borrego Springs, Thermal, Hwy S22 Between
Borrego Springs And Imperial County Line, Highway 86, La Quinta,
Mecca and Santa Rosa Mountain.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Remain alert for flooding even in locations not receiving rain.
Arroyos, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.
&&
LAT...LON 3366 11622 3377 11604 3374 11600 3374 11595
3351 11595 3352 11605 3351 11605 3350 11607
3343 11603 3343 11609 3323 11608 3325 11637
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
Gregoria2 follow-up statements
166
WGUS76 KSGX 010147
FFSSGX
Flash Flood Statement
National Weather Service San Diego CA
647 PM PDT Tue Aug 31 2021
CAC065-073-010345-
/O.CON.KSGX.FF.W.0012.000000T0000Z-210901T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-San Diego CA-
647 PM PDT Tue Aug 31 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM PDT THIS
EVENING FOR RIVERSIDE AND NORTHEASTERN SAN DIEGO COUNTIES...
At 647 PM PDT, Doppler radar indicated that the heaviest rain has
ended over the warning area. However, the recent heavy rain has
likely lead to flooding which will take some time to drain.
HAZARD...Life threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Radar.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flash flooding include...
Highway 86, Hwy S22 Between Borrego Springs And Imperial County
Line, Box Canyon, Mecca and Santa Rosa Mountain.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Remain alert for flooding even in locations not receiving rain.
Arroyos, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.
&&
LAT...LON 3366 11622 3377 11604 3374 11600 3374 11595
3351 11595 3352 11605 3351 11605 3350 11607
3343 11603 3343 11609 3323 11608 3325 11637
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
Gregoria380
WGUS76 KSGX 010220
FFSSGX
Flash Flood Statement
National Weather Service San Diego CA
720 PM PDT Tue Aug 31 2021
CAC065-073-010230-
/O.CAN.KSGX.FF.W.0012.000000T0000Z-210901T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-San Diego CA-
720 PM PDT Tue Aug 31 2021
...FLASH FLOOD WARNING IS CANCELLED FOR RIVERSIDE AND NORTHEASTERN
SAN DIEGO COUNTIES...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
A Flash Flood Watch remains in effect until 1000 PM PDT for the area.
LAT...LON 3366 11622 3377 11604 3374 11600 3374 11595
3351 11595 3352 11605 3351 11605 3350 11607
3343 11603 3343 11609 3323 11608 3325 11637
$$
GregoriaThe office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 31, 5:17 PM PDT | Severe Thunderstorm Warning | SGX | Riverside, San Diego | 58 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.