Alert archive / California / Flash Flood Warnings in 2021
Flash Flood Warning 48, NWS Las Vegas, NV
NWS Las Vegas, NV issued this flash flood warning at Jul 21, 2021, 5:18 PM PDT for San Bernardino County, California. It was in force for 2 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
- Jul 21, 2021, 5:18 PM PDT (00:18 UTC)
- Expired
- Jul 21, 2021, 7:44 PM PDT
- In force
- 2 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), 88 km from the middle of the area, began a volume at 00:17 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, 0.3 hours before the alert went out and 179 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
- 6 J/kg
- Mixed-layer CIN
- -92 J/kg
- Mixed-layer LCL
- 3146 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 14 m²/s²
- 0-3 km storm-relative helicity
- 3 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
826
WGUS55 KVEF 220018
FFWVEF
CAC071-220315-
/O.NEW.KVEF.FF.W.0048.210722T0018Z-210722T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
518 PM PDT Wed Jul 21 2021
The National Weather Service in Las Vegas has issued a
* Flash Flood Warning for...
San Bernardino County in southern California...
* Until 815 PM PDT.
* At 518 PM PDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. 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...
Needles, Mohave Valley, and Needle Highway.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.
&&
LAT...LON 3491 11469 3504 11470 3502 11466 3497 11463
3496 11464 3494 11463 3492 11463 3491 11463
3489 11464 3487 11463 3488 11466
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
AN2 follow-up statements
430
WGUS75 KVEF 220150
FFSVEF
Flash Flood Statement
National Weather Service Las Vegas NV
650 PM PDT Wed Jul 21 2021
CAC071-220315-
/O.CON.KVEF.FF.W.0048.000000T0000Z-210722T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
650 PM PDT Wed Jul 21 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM PDT THIS
EVENING FOR SAN BERNARDINO COUNTY...
At 650 PM PDT, Doppler radar indicated thunderstorms producing
periods of heavy rain across the warned area. While the initial
heavy rainfall has moved out of the warned area, more development is
occurring and approaching. Flash flooding will continue to be
possible in the warned area.
HAZARD...Life-threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Radar.
IMPACT...Life-threatening flash flooding of low-water crossings,
creeks, normally dry washes and roads.
Some locations that will experience flash flooding include...
Needles, Mohave Valley, and Needles Highway.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.
&&
LAT...LON 3491 11469 3504 11470 3502 11466 3497 11463
3496 11464 3494 11463 3492 11463 3491 11463
3489 11464 3487 11463 3488 11466
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
TB362
WGUS75 KVEF 220244
FFSVEF
Flash Flood Statement
National Weather Service Las Vegas NV
744 PM PDT Wed Jul 21 2021
CAC071-220254-
/O.CAN.KVEF.FF.W.0048.000000T0000Z-210722T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
744 PM PDT Wed Jul 21 2021
...FLASH FLOOD WARNING IS CANCELLED FOR SAN BERNARDINO COUNTY...
The heavy rain has ended and only light rainfall is expected over
the next few hours. Flash Flooding is no longer expected to pose a
threat along Needles Highway. However, if you encounter any water
over the roadway, do not attempt to cross it.
LAT...LON 3491 11469 3504 11470 3502 11466 3497 11463
3496 11464 3494 11463 3492 11463 3491 11463
3489 11464 3487 11463 3488 11466
$$
TBNearby
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.