Alert archive / Nevada / Flash Flood Warnings in 2021
Flash Flood Warning 111, NWS Las Vegas, NV
NWS Las Vegas, NV issued this flash flood warning at Aug 12, 2021, 7:46 PM PDT for Clark County, Nevada. 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 12, 2021, 7:46 PM PDT (02:46 UTC)
- Expired
- Aug 12, 2021, 10:45 PM PDT
- In force
- 3 hr
- Issued by
- NWS Las Vegas, NV
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
County Clark County, NV
The radar
The Las Vegas radar (KESX), 101 km from the middle of the area, began a volume at 02:49 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 00:00Z, 2.8 hours before the alert went out and 79 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
- 1235 J/kg
- Mixed-layer CIN
- -41 J/kg
- Mixed-layer LCL
- 2944 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 2 m²/s²
- 0-3 km storm-relative helicity
- 96 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
439
WGUS55 KVEF 130246
FFWVEF
NVC003-130545-
/O.NEW.KVEF.FF.W.0111.210813T0246Z-210813T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
746 PM PDT Thu Aug 12 2021
The National Weather Service in Las Vegas has issued a
* Flash Flood Warning for...
North Central Clark County in southern Nevada...
* Until 1045 PM PDT.
* At 746 PM PDT, Doppler radar indicated thunderstorms producing
heavy rain between Moapa and Apex. Additional Heavy rainfall may
develop southward towards Valley of Fire. Between 0.5 and 1.25
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 low-water
crossings, creeks, normally dry washes and roads.
* Some locations that will experience flash flooding include...
Moapa Town and Valley Of Fire.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3677 11484 3680 11475 3673 11464 3666 11454
3655 11453 3643 11447 3638 11451 3633 11466
3639 11481 3657 11489 3674 11488
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
CO2 follow-up statements
042
WGUS75 KVEF 130335
FFSVEF
Flash Flood Statement
National Weather Service Las Vegas NV
835 PM PDT Thu Aug 12 2021
NVC003-130545-
/O.CON.KVEF.FF.W.0111.000000T0000Z-210813T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
835 PM PDT Thu Aug 12 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM PDT THIS
EVENING FOR NORTH CENTRAL CLARK COUNTY...
At 835 PM PDT, Doppler radar indicated the heaviest rain has begun
to shift south of Valley of Fire. However, rain gauges near Crystal
reported between 0.75 inches and 1 inch of rain in the past hour.
Local washes and drainages including the California Wash and Muddy
River will continue to run high and pose a flash flood risk.
HAZARD...Life-threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Radar.
IMPACT...Life-threatening flash flooding of low-water crossings,
creeks, normally dry washes and roads.
Some locations that will experience flash flooding include...
Moapa Town and Valley Of Fire.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3677 11484 3680 11475 3673 11464 3666 11454
3655 11453 3643 11447 3638 11451 3633 11466
3639 11481 3657 11489 3674 11488
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
CO490
WGUS75 KVEF 130538
FFSVEF
Flash Flood Statement
National Weather Service Las Vegas NV
1038 PM PDT Thu Aug 12 2021
NVC003-130548-
/O.EXP.KVEF.FF.W.0111.000000T0000Z-210813T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
1038 PM PDT Thu Aug 12 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 1045 PM PDT THIS EVENING FOR
NORTH CENTRAL CLARK COUNTY...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
LAT...LON 3677 11484 3680 11475 3673 11464 3666 11454
3655 11453 3643 11447 3638 11451 3633 11466
3639 11481 3657 11489 3674 11488
$$
COThe office that day
Everything else NWS Las Vegas, NV issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 12, 7:06 PM PDT | Severe Thunderstorm Warning | VEF | Clark | 39 min |
| Aug 12, 7:40 PM PDT | Severe Thunderstorm Warning | VEF | Clark | 50 min |
| Aug 12, 8:17 PM PDT | Severe Thunderstorm Warning | VEF | Clark | 58 min |
| Aug 12, 8:42 PM PDT | Flash Flood Warning | VEF | Clark | 3 hr |
| Aug 12, 9:10 PM PDT | Severe Thunderstorm Warning | VEF | Clark | 50 min |
| Aug 13, 2:37 AM PDT | Excessive Heat Watch | VEF | Clark, Nye | 12 hr |
| Aug 13, 2:18 PM PDT | Excessive Heat Warning | VEF | Clark, Nye | 3 days |
| Aug 13, 2:23 PM PDT | Severe Thunderstorm Warning | VEF | Clark | 52 min |
Nearby
Flash Flood Warnings in Nevada, 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.