Alert archive / California / Flash Flood Warnings in 2020

Flash Flood Warning 4, NWS Las Vegas, NV

March 12, 2020San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Mar 12, 2020, 4:32 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
Mar 12, 2020, 4:32 PM PDT (23:32 UTC)
Expired
Mar 12, 2020, 7:30 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 Edwards AFB radar (KEYX), 85 km from the middle of the area, began a volume at 23:30 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, 11.5 hours before the alert went out and 197 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 2020-03-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 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 2020-03-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -14 square meters per square second.1939587897117136Sfc1 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
3 J/kg
Mixed-layer CIN
-54 J/kg
Mixed-layer LCL
1191 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
-14 m²/s²
0-3 km storm-relative helicity
81 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

652 
WGUS55 KVEF 122332
FFWVEF
CAC071-130230-
/O.NEW.KVEF.FF.W.0004.200312T2332Z-200313T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
432 PM PDT Thu Mar 12 2020

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  West central San Bernardino County in southern California...

* Until 730 PM PDT.

* At 426 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the Barstow-Daggett area. Law enforcement has 
  reported water along the Outlet Center Dr and Interstate 15 off-
  ramp. Continued moderate to heavy rainfall is expected over the 
  next few hours. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Life threatening flash flooding. Heavy rain producing 
           flash flooding.

  SOURCE...Radar indicated.

  IMPACT...Life threatening flash flooding of creeks and streams, 
           urban areas, highways, streets and underpasses.

* Some locations that will experience flooding include...
  Barstow, Daggett, I-15 Between Victorville And Barstow, Afton
  Canyon Campground, Newberry Springs, Owl Canyon Campground, Hwy 247
  Between Lucerne Valley And Barstow, Lenwood and Nebo Center.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3471 11645 3474 11642 3481 11736 3518 11734
      3519 11633 3470 11635

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

CK
2 follow-up statements
578 
WGUS75 KVEF 130153
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
653 PM PDT Thu Mar 12 2020

CAC071-130230-
/O.CON.KVEF.FF.W.0004.000000T0000Z-200313T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
653 PM PDT Thu Mar 12 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM PDT FOR
WEST CENTRAL SAN BERNARDINO COUNTY...

At 649 PM PDT, trained weather spotters reported nearly an inch of 
rain has fallen in the past hour. Heavy rain is occurring from 
Barstow westward along Highway 58 to the county line. Flash flooding 
is ongoing or expected to begin shortly.

HAZARD...Life threatening flash flooding. Heavy rain producing flash 
         flooding.

SOURCE...Trained weather spotters.

IMPACT...Life threatening flash flooding of creeks and streams, 
         urban areas, highways, streets and underpasses.

Some locations that will experience flooding include...
Barstow, Daggett, I-15 Between Victorville And Barstow, Afton Canyon
Campground, Newberry Springs, Owl Canyon Campground, Hwy 247 Between
Lucerne Valley And Barstow, Lenwood and Nebo Center.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3471 11645 3474 11642 3481 11736 3518 11734
      3519 11633 3470 11635

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

SC
410 
WGUS75 KVEF 130228
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
728 PM PDT Thu Mar 12 2020

CAC071-130234-
/O.EXP.KVEF.FF.W.0004.000000T0000Z-200313T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
728 PM PDT Thu Mar 12 2020

...THE FLASH FLOOD WARNING FOR WEST CENTRAL SAN BERNARDINO COUNTY
WILL EXPIRE AT 730 PM PDT...

The heavy rain has moved to the west but continues along Highway 58 
from near Hinkley westward to the county line. Flooding is no longer 
expected to pose a threat. Please continue to heed any remaining 
road closures.

LAT...LON 3471 11645 3474 11642 3481 11736 3518 11734
      3519 11633 3470 11635

$$

SC

The office that day

Everything else NWS Las Vegas, NV issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 12, 2:54 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino2 hr
Mar 12, 3:26 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino3 hr
Mar 12, 4:07 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino4 hr

Nearby

Flash Flood Warnings in California, 2020Every flash flood warning in 2020

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.