Alert archive / California / Flash Flood Warnings in 2021
Flash Flood Warning 121, NWS Las Vegas, NV
NWS Las Vegas, NV issued this flash flood warning at Aug 30, 2021, 2:37 PM PDT for San Bernardino County, California. It was in force for 3 hr. 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 30, 2021, 2:37 PM PDT (21:37 UTC)
- Expired
- Aug 30, 2021, 5:45 PM PDT
- In force
- 3 hr
- Issued by
- NWS Las Vegas, NV
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
County San Bernardino County, CA
The radar
The Las Vegas radar (KESX), 79 km from the middle of the area, began a volume at 21:38 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
Las Vegas, NV (KVEF), launched 12:00Z, 9.6 hours before the alert went out and 129 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
- 37 J/kg
- Mixed-layer CIN
- -324 J/kg
- Mixed-layer LCL
- 3297 m above ground
- 0-6 km bulk shear
- 2 kt
- 0-1 km storm-relative helicity
- -27 m²/s²
- 0-3 km storm-relative helicity
- 39 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
355
WGUS55 KVEF 302137
FFWVEF
CAC071-310045-
/O.NEW.KVEF.FF.W.0121.210830T2137Z-210831T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
237 PM PDT Mon Aug 30 2021
The National Weather Service in Las Vegas has issued a
* Flash Flood Warning for...
San Bernardino County in southern California...
* Until 545 PM PDT.
* At 237 PM PDT, Doppler radar indicated numerous thunderstorms
producing heavy rain across the Mojave National Preserve. 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 low-water
crossings, normally dry washes and roads.
* Some locations that will experience flash flooding include...
Nipton, Ivanpah, Cima and Kelbaker roads.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3494 11549 3489 11581 3511 11581 3537 11567
3544 11554 3547 11543 3547 11539 3540 11537
3517 11539
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
JA2 follow-up statements
265
WGUS75 KVEF 302254
FFSVEF
Flash Flood Statement
National Weather Service Las Vegas NV
354 PM PDT Mon Aug 30 2021
CAC071-310045-
/O.CON.KVEF.FF.W.0121.000000T0000Z-210831T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
354 PM PDT Mon Aug 30 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM PDT THIS
AFTERNOON FOR SAN BERNARDINO COUNTY...
At 354 PM PDT, Doppler radar indicated thunderstorms were
diminishing across the western Mojave National Preserve from Cima to
Kelso. However, earlier heavy rainfall in the warned area will lead
to flash flooding of roads.
HAZARD...Life-threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Radar.
IMPACT...Life-threatening flash flooding of low-water crossings,
normally dry washes and roads.
Some locations that will experience flash flooding include...
Cima Road, Kelso Cima Road, Kelbaker Road, and Ivanpah Road.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3494 11549 3489 11581 3511 11581 3537 11567
3544 11554 3547 11543 3547 11539 3540 11537
3517 11539
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
JA306
WGUS75 KVEF 310043
FFSVEF
Flash Flood Statement
National Weather Service Las Vegas NV
543 PM PDT Mon Aug 30 2021
CAC071-310053-
/O.EXP.KVEF.FF.W.0121.000000T0000Z-210831T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
543 PM PDT Mon Aug 30 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 545 PM PDT THIS AFTERNOON FOR
EASTERN SAN BERNARDINO COUNTY...
Flooding is no longer expected to pose a threat for the Mojave
National Preserve from Cima to Kelso and nearby sections of roads.
Please continue to watch for any lingering shallow runoff in low
spots and slow down.
LAT...LON 3494 11549 3489 11581 3511 11581 3537 11567
3544 11554 3547 11543 3547 11539 3540 11537
3517 11539
$$
JAThe office that day
Everything else NWS Las Vegas, NV issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 29, 6:53 PM PDT | Flash Flood Warning | VEF | San Bernardino | 3 hr |
| Aug 30, 3:28 AM PDT | Flash Flood Watch | VEF | San Bernardino | 59 hr |
| Aug 30, 1:17 PM PDT | Flash Flood Warning | VEF | San Bernardino | 3 hr |
| Aug 30, 2:55 PM PDT | Flash Flood Warning | VEF | 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.