Alert archive / California / Flash Flood Warnings in 2021
Flash Flood Warning 9, NWS San Diego, CA
NWS San Diego, CA issued this flash flood warning at Aug 10, 2021, 11:27 PM PDT for Riverside County, San Diego County, California. It was in force for 3 hr. 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
- Aug 10, 2021, 11:27 PM PDT (06:27 UTC)
- Expired
- Aug 11, 2021, 2:30 AM PDT
- In force
- 3 hr
- 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), 79 km from the middle of the area, began a volume at 06:31 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 |
|---|---|---|---|
| Aug 10, 11:47 PM PDT | FLASH FLOOD | 8 Ene Borrego Springs, CA | CHP REPORTED FLASH FLOODING AT BORREGO SALTON SEAWAY (S22) AT FONTS WASH. CAR WAS STUCK IN THE LOW WATER CROSSING. |
| Aug 11, 12:42 AM PDT | FLASH FLOOD | 11 Ene Borrego Springs, CA | FLASH FLOOD ON BORREGO SALTON SEAWAY AT PALO VERDE WASH. TWO CARS STUCK IN WATER AND MUD. MOTORISTS ABANDONED THEIR VEHICLES AND FLED TO HIGHER GROUND. CHP CLOSED THE ROAD. |
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 00:00Z, 6.5 hours before the alert went out and 98 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
- 3091 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 21 m²/s²
- 0-3 km storm-relative helicity
- 54 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
137
WGUS56 KSGX 110627
FFWSGX
CAC065-073-110930-
/O.NEW.KSGX.FF.W.0009.210811T0627Z-210811T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Diego CA
1127 PM PDT Tue Aug 10 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 230 AM PDT.
* At 1127 PM PDT, Doppler radar indicated thunderstorms producing
heavy rain across the Santa Rosa Mountains, across the San Diego
deserts and along the desert mountain slopes. Heavy rainfall of 1
inch per hour is occurring across these areas, which will result
in flash flooding.
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...
Borrego Springs, Hwy 78 Between Borrego Springs Rd And Ocotillo
Wells, Hwy 78 Between Banner And S2, southeastern Anza, Hwy S22
Between Ranchita And Borrego Springs, Borrego Palm Canyon,
Ranchita, Hwy S2 Between Shelter Valley And Agua Caliente, Warner
Springs, Ocotillo Wells, Hwy 79 Between Julian And Lake Cuyamaca,
Fish Creek Wash and Hwy 74 Between Anza And Palm Desert.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 3356 11662 3364 11640 3347 11606 3343 11606
3343 11609 3307 11608 3307 11610 3305 11610
3289 11653 3301 11657 3332 11663
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
Gregoria3 follow-up statements
547
WGUS76 KSGX 110719
FFSSGX
Flash Flood Statement
National Weather Service San Diego CA
1219 AM PDT Wed Aug 11 2021
CAC065-073-110930-
/O.CON.KSGX.FF.W.0009.000000T0000Z-210811T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-San Diego CA-
1219 AM PDT Wed Aug 11 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM PDT EARLY THIS
MORNING FOR RIVERSIDE AND NORTHEASTERN SAN DIEGO COUNTIES...
At 1219 AM PDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. The heaviest thunderstorms are
impacting areas just east of Julian along Highway 78 where
torrential rainfall is occurring and likely leading to flash
flooding, mud and rock slides. The heavy rain also extends north
along the desert mountain slopes as well as across the desert to the
south of Borrego Springs. CHP reported flash flooding at Borrego
Salton Seaway, Highway S22, at Fonts Wash. Rainfall recorded so far
has been 1.66 inches at San Felipe Wash, 1.46 inches at Coyote Creek
Canyon, and 0.93 inches at Ranchita. Additional rainfall of 1 inch
is expected.
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...
Borrego Springs, Hwy 78 Between Borrego Springs Rd And Ocotillo
Wells, Hwy 78 Between Banner And S2, Julian, Cuyamaca Rancho State
Park, northern Mount Laguna, southeastern Anza, Hwy S22 Between
Ranchita And Borrego Springs, Borrego Palm Canyon, Ranchita, Warner
Springs, Ocotillo Wells, Hwy 79 Between Julian And Lake Cuyamaca,
Fish Creek Wash and Hwy 74 Between Anza And Palm Desert.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 3356 11662 3364 11640 3347 11606 3343 11606
3343 11609 3307 11608 3307 11610 3305 11610
3289 11653 3301 11657 3332 11663
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
Gregoria978
WGUS76 KSGX 110844
FFSSGX
Flash Flood Statement
National Weather Service San Diego CA
144 AM PDT Wed Aug 11 2021
CAC065-073-110930-
/O.CON.KSGX.FF.W.0009.000000T0000Z-210811T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-San Diego CA-
144 AM PDT Wed Aug 11 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM PDT EARLY THIS
MORNING FOR RIVERSIDE AND NORTHEASTERN SAN DIEGO COUNTIES...
At 144 AM PDT, Doppler radar indicated that the rain was diminishing
in intensity over the warned area. However, significant rain has
fallen over the past couple of hours with amounts in excess of 2
inches just east of Julian along Highway 78 with 2.33 inches at San
Felipe Wash. 1 to 2 inches of rain has fallen in the Ranchita area.
Light to moderate rain continues with additional amounts of around a
quarter of an inch expected. The recent heavy rainfall will continue
to lead to flash flooding as the water drains off.
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...
Borrego Springs, Hwy 78 Between Borrego Springs Rd And Ocotillo
Wells, Hwy 78 Between Banner And S2, Julian, Cuyamaca Rancho State
Park, southeastern Anza, Hwy S22 Between Ranchita And Borrego
Springs, Borrego Palm Canyon, Ranchita, Hwy S22 Between Borrego
Springs And Imperial County Line, Hwy 79 Between Julian And Lake
Cuyamaca, Fish Creek Wash and Hwy 74 Between Anza And Palm Desert.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 3356 11662 3364 11640 3347 11606 3343 11606
3343 11609 3307 11608 3307 11610 3305 11610
3289 11653 3301 11657 3332 11663
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
Gregoria992
WGUS76 KSGX 110930
FFSSGX
Flash Flood Statement
National Weather Service San Diego CA
230 AM PDT Wed Aug 11 2021
CAC065-073-110935-
/O.EXP.KSGX.FF.W.0009.000000T0000Z-210811T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-San Diego CA-
230 AM PDT Wed Aug 11 2021
...THE FLASH FLOOD WARNING FOR RIVERSIDE AND NORTHEASTERN SAN DIEGO
COUNTIES WILL EXPIRE AT 230 AM PDT...
The heavy rain over the Anza Borrego Desert has ended, but light
rain will continue through 4 AM. Flooding was reported on the
Borrego Salton Seaway between Borrego Springs and Salton City.
Flooding and debris flows were also reported on Highway 78 near
Yaqui Pass road.
Please continue to heed any remaining road closures.
LAT...LON 3356 11662 3364 11640 3347 11606 3343 11606
3343 11609 3307 11608 3307 11610 3305 11610
3289 11653 3301 11657 3332 11663
$$
MGMThe office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 10, 9:33 PM PDT | Dust Storm Warning | SGX | Riverside, San Diego | 57 min |
| Aug 10, 10:26 PM PDT | Areal Flood Advisory | SGX | Riverside, San Diego | 3 hr |
| Aug 10, 10:31 PM PDT | Dust Storm Advisory | SGX | San Diego | 59 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.