Alert archive / California / Flash Flood Warnings in 2021
Flash Flood Warning 22, NWS San Diego, CA
NWS San Diego, CA issued this flash flood warning at Dec 14, 2021, 11:01 AM PST for Orange County, California. It was in force for 89 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
- Dec 14, 2021, 11:01 AM PST (19:01 UTC)
- Expired
- Dec 14, 2021, 12:30 PM PST
- In force
- 89 min
- Issued by
- NWS San Diego, CA
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
County Orange County, CA
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Dec 14, 12:00 PM PST | FLASH FLOOD | 9 Ssw Corona, CA | REPORTED 6 DEBRIS FLOWS IN BOND FIRE SCAR AND 4 IN SILVERADO CANYON. SANTIAGO CREEK ROAD BLOCKAGE FROM HIGH WATER FLOWS AND MUD. JACKSON CREEK ROAD FLOODED WITH MUD AND DEBRIS. RAINFALL RATES OF UP TO 1.2 INCHES REPORTED AT IRVINE LAKE AND SANTIAGO CANYON SITE |
| Dec 14, 12:30 PM PST | FLASH FLOOD | 9 Nne Lake Forest, CA | PHOTO FROM WEATHER SPOTTER SHARED BY PUBLIC SHOWED 5 FEET OF DEBRIS, MUD AND ROCKS ON SILVERADO CANYON ROAD LOWER PORTION NEAR SANTIAGO CANYON ROAD. ESTIMATED TIME. ROAD WAS COMPLETED COVERED AT THE DEBRIS CROSSING. |
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, 7.0 hours before the alert went out and 115 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
- 1 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 666 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 200 m²/s²
- 0-3 km storm-relative helicity
- 172 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
514
WGUS56 KSGX 141901
FFWSGX
CAC059-142030-
/O.NEW.KSGX.FF.W.0022.211214T1901Z-211214T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Diego CA
1101 AM PST Tue Dec 14 2021
The National Weather Service in San Diego has issued a
* Flash Flood Warning for...
The Bond burn scar in...
Northeastern Orange County in southwestern California...
* Until 1230 PM PST.
* At 1101 AM PST, Doppler radar and automated rain gauges indicated
heavy rain falling over the Bond Burn Scar. The expected rainfall
rate is 0.5 to 0.75 inches in 1 hour. Flash flooding is ongoing or
expected to begin shortly.
Excessive rainfall over the burn scar will result in debris flow
moving through the White Canyon, Wildcat Canyon, Williams Canyon,
and Modjeska Canyon. The debris flow can consist of rock, mud,
vegetation and other loose materials.
HAZARD...Life threatening flash flooding. Heavy rain producing
flash flooding in and around the Bond Burn Scar.
SOURCE...Radar and automated gauges.
IMPACT...Life threatening flash flooding of areas in and around
the Bond Burn Scar.
* Some locations that will experience flash flooding include...
Irvine, Silverado, Foothill Ranch and Limestone Canyon Regional
Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This is a life threatening situation. Heavy rainfall may cause
extensive and severe flash flooding of creeks, streams, and ditches
in the Bond Burn Scar. Severe debris flows can also be anticipated
across roads. Roads and driveways may be washed away in places. If
you encounter flood waters, climb to safety.
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3376 11774 3378 11771 3374 11760 3370 11764
FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL RATE...0.5-0.75 INCHES IN 1 HOUR
$$
Connolly1 follow-up statement
251 WGUS76 KSGX 142030 FFSSGX Flash Flood Statement National Weather Service San Diego CA 1230 PM PST Tue Dec 14 2021 CAC059-142040- /O.EXP.KSGX.FF.W.0022.000000T0000Z-211214T2030Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Orange CA- 1230 PM PST Tue Dec 14 2021 ...FLASH FLOOD WARNING FOR THE BOND BURN SCAR HAS EXPIRED FOR NORTHEASTERN ORANGE COUNTY... The heavy rain has ended for now. Flooding is no longer expected to pose a threat. Please continue to heed remaining road closures. A Flood Watch remains in effect until 900 PM PST Tuesday for a portion of Southern California. LAT...LON 3376 11774 3378 11771 3374 11760 3370 11764 $$ Connolly
The office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 14, 7:34 AM PST | Areal Flood Advisory | SGX | Orange, Riverside | 4 hr |
| Dec 14, 8:09 AM PST | Areal Flood Advisory | SGX | Orange | 4 hr |
| Dec 14, 9:23 AM PST | Areal Flood Advisory | SGX | San Bernardino | 4 hr |
| Dec 14, 10:36 AM PST | Flash Flood Warning | SGX | Orange | 3 hr |
| Dec 14, 11:46 AM PST | Areal Flood Advisory | SGX | San Diego | 3 hr |
| Dec 14, 1:00 PM PST | Areal Flood Advisory | SGX | Riverside, San Bernardino | 3 hr |
| Dec 14, 1:15 PM PST | Areal Flood Advisory | SGX | San Diego | 3 hr |
| Dec 14, 1:27 PM PST | Flash Flood Warning | SGX | Riverside, San Bernardino | 108 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.