Alert archive / California / Flash Flood Warnings in 2021

Flash Flood Warning 9, NWS Las Vegas, NV

July 14, 2021San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 14, 2021, 2:47 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
Jul 14, 2021, 2:47 PM PDT (21:47 UTC)
Expired
Jul 14, 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 nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 9.8 hours before the alert went out and 106 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.

Skew-T log-pSkew-T log-p diagram, Las Vegas, NV at 12:00Z on 2021-07-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 448 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 12:00Z on 2021-07-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -19 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
448 J/kg
Mixed-layer CIN
-374 J/kg
Mixed-layer LCL
2057 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-19 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

545 
WGUS55 KVEF 142147
FFWVEF
CAC071-150045-
/O.NEW.KVEF.FF.W.0009.210714T2147Z-210715T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
247 PM PDT Wed Jul 14 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 247 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain along Ivanpah and Nipton Roads. 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...
  Nipton And Ivanpah Roads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 3545 11553 3545 11548 3547 11543 3550 11535
      3545 11530 3532 11537 3534 11553

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

SC
2 follow-up statements
275 
WGUS75 KVEF 142304
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
404 PM PDT Wed Jul 14 2021

CAC071-150045-
/O.CON.KVEF.FF.W.0009.000000T0000Z-210715T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
404 PM PDT Wed Jul 14 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM PDT THIS 
AFTERNOON FOR SAN BERNARDINO COUNTY...

At 404 PM PDT, Doppler radar indicated that the earlier 
thunderstorms have moved to the north toward Interstate 15 near 
Primm. However, runoff from the earlier heavy rain is still likely 
impacting Ivanpah and Nipton Roads. 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...
  Nipton And Ivanpah Roads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 3545 11553 3545 11548 3547 11543 3550 11535
      3545 11530 3532 11537 3534 11553

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

SC
067 
WGUS75 KVEF 150041
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
541 PM PDT Wed Jul 14 2021

CAC071-150051-
/O.EXP.KVEF.FF.W.0009.000000T0000Z-210715T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
541 PM PDT Wed Jul 14 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 545 PM PDT THIS AFTERNOON FOR 
SAN BERNARDINO COUNTY...

The heavy rain has ended and the storm has moved out of the area. 
Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures, if applicable.

LAT...LON 3545 11553 3545 11548 3547 11543 3550 11535
      3545 11530 3532 11537 3534 11553

$$

JV

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.