Alert archive / California / Flash Flood Warnings in 2021
Flash Flood Warning 100, NWS Phoenix, AZ
NWS Phoenix, AZ issued this flash flood warning at Jul 26, 2021, 3:36 AM PDT for Riverside County, California. It was in force for 6 hr. 1 report 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
- Jul 26, 2021, 3:36 AM PDT (10:36 UTC)
- Expired
- Jul 26, 2021, 9:30 AM PDT
- In force
- 6 hr
- Issued by
- NWS Phoenix, AZ
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
County Riverside County, CA
The radar
The San Diego radar (KNKX), 131 km from the middle of the area, began a volume at 10:40 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 26, 3:50 AM PDT | FLASH FLOOD | 13 Ssw Jtnp-Cottonwood, CA | *** DELAYED REPORT *** BOX CANYON RD. NEAR SHAVERS WELL CLOSED DUE TO SAND AND ROCK DEBRIS FROM FLOODING. TIME ESTIMATED FROM FIRST CALL TO CHP REGARDING BOX CANYON RD. AT 4:08 AM. |
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, 10.6 hours before the alert went out and 150 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
- 1166 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 36 m²/s²
- 0-3 km storm-relative helicity
- 90 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
801
WGUS55 KPSR 261036
FFWPSR
CAC065-261630-
/O.NEW.KPSR.FF.W.0100.210726T1036Z-210726T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
336 AM PDT Mon Jul 26 2021
The National Weather Service in Phoenix has issued a
* Flash Flood Warning for...
Riverside County in southern California...
* Until 930 AM PDT.
* At 336 AM PDT, Doppler radar indicated thunderstorms producing
heavy rain in Box Canyon. Between 1.0 and 1.5 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...
mainly rural areas of Riverside County
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3363 11587 3360 11589 3357 11590 3356 11595
3363 11595 3363 11593 3365 11589
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
CK2 follow-up statements
632
WGUS75 KPSR 261150
FFSPSR
Flash Flood Statement
National Weather Service Phoenix AZ
450 AM PDT Mon Jul 26 2021
CAC065-261630-
/O.CON.KPSR.FF.W.0100.000000T0000Z-210726T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-
450 AM PDT Mon Jul 26 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 AM PDT THIS
MORNING FOR RIVERSIDE COUNTY...
At 450 AM PDT, Doppler radar indicated thunderstorms producing heavy
rain in Box Canyon. Between 1 and 2 inches of rain have fallen.
Flash flooding is ongoing or expected to begin shortly.
HAZARD...Life threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Radar.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flash flooding include...
mainly rural areas of Riverside County
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3363 11587 3360 11589 3357 11590 3356 11595
3363 11595 3363 11593 3365 11589
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
CK606
WGUS75 KPSR 261626
FFSPSR
Flash Flood Statement
National Weather Service Phoenix AZ
926 AM PDT Mon Jul 26 2021
CAC065-261636-
/O.EXP.KPSR.FF.W.0100.000000T0000Z-210726T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-
926 AM PDT Mon Jul 26 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 930 AM PDT THIS MORNING FOR
RIVERSIDE COUNTY...
Flood waters have receded. The heavy rain has ended. Flooding is no
longer expected to pose a threat. Please continue to heed remaining
road closures.
LAT...LON 3363 11587 3360 11589 3357 11590 3356 11595
3363 11595 3363 11593 3365 11589
$$
SDBThe office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 25, 6:13 PM PDT | Flash Flood Warning | PSR | Riverside | 4 hr |
| Jul 25, 6:35 PM PDT | Flash Flood Warning | PSR | Riverside | 4 hr |
| Jul 25, 6:54 PM PDT | Flash Flood Warning | PSR | Imperial | 4 hr |
| Jul 25, 8:08 PM PDT | Flash Flood Warning | PSR | Imperial | 4 hr |
| Jul 26, 1:52 AM PDT | Areal Flood Advisory | PSR | Imperial | 3 hr |
| Jul 26, 6:49 AM PDT | Areal Flood Advisory | PSR | Riverside | 3 hr |
| Jul 26, 8:01 AM PDT | Areal Flood Advisory | PSR | Riverside, San Bernardino | 3 hr |
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.