Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 72, NWS Las Vegas, NV

August 3, 2017San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Aug 3, 2017, 8:59 AM 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 3, 2017, 8:59 AM PDT (15:59 UTC)
Expired
Aug 3, 2017, 12:00 PM PDT
In force
3 hr
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

County San Bernardino County, CA

The radar

The Las Vegas radar (KESX), 183 km from the middle of the area, began a volume at 16:00 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

Yuma Prvg Ground, AZ (K1Y7), launched 12:00Z, 4.0 hours before the alert went out and 199 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, Yuma Prvg Ground, AZ at 12:00Z on 2017-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 643 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, Yuma Prvg Ground, AZ at 12:00Z on 2017-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 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
643 J/kg
Mixed-layer CIN
-190 J/kg
Mixed-layer LCL
1749 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
33 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

752 
WGUS55 KVEF 031559
FFWVEF
CAC071-031900-
/O.NEW.KVEF.FF.W.0072.170803T1559Z-170803T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
859 AM PDT THU AUG 3 2017

The National Weather Service in Las Vegas has issued a

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

* Until noon PDT

* At 858 AM PDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is expected to
  begin shortly.  Rain has been persistent over the past few hours.

* Some locations that will experience flooding include...
  Vidal Junction.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3404 11572 3424 11570 3422 11445 3408 11446
      3407 11532 3412 11552 3407 11555 3409 11560
      3403 11560

$$

DSB
2 follow-up statements
253 
WGUS75 KVEF 031759
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1059 AM PDT THU AUG 3 2017

CAC071-031900-
/O.CON.KVEF.FF.W.0072.000000T0000Z-170803T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
1059 AM PDT THU AUG 3 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL NOON PDT FOR
SOUTHEASTERN SAN BERNARDINO COUNTY...

At 1059 AM PDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area.  Flash flooding is expected to begin
shortly.

Some locations that will experience flooding include...
Vidal Junction.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3404 11572 3424 11570 3422 11445 3408 11446
      3407 11532 3412 11552 3407 11555 3409 11560
      3403 11560

$$

DSB
454 
WGUS75 KVEF 031858
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1158 AM PDT THU AUG 3 2017

CAC071-031908-
/O.EXP.KVEF.FF.W.0072.000000T0000Z-170803T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
1158 AM PDT THU AUG 3 2017

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN SAN BERNARDINO COUNTY
WILL EXPIRE AT NOON PDT...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. However, there may still be areas of standing water along 
Highway 62 and local side roads. Please continue to heed any 
remaining road closures.

LAT...LON 3404 11572 3424 11570 3422 11445 3408 11446
      3407 11532 3412 11552 3407 11555 3409 11560
      3403 11560

$$

ASG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 5:53 PM PDTFlash Flood WarningVEFInyo2 hr
Aug 2, 7:19 PM PDTSevere Thunderstorm WarningVEFSan Bernardino26 min
Aug 2, 7:36 PM PDTFlash Flood WarningVEFInyo3 hr
Aug 2, 8:09 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Aug 2, 8:19 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Aug 2, 8:57 PM PDTAreal Flood AdvisoryVEFInyo3 hr
Aug 2, 9:54 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 2, 10:04 PM PDTFlash Flood WarningVEFInyo, San Bernardino3 hr
Aug 2, 11:36 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 3, 2:27 AM PDTFlash Flood WatchVEFInyo, San Bernardino21 hr
Aug 3, 6:02 AM PDTFlash Flood WarningVEFSan Bernardino3 hr
Aug 3, 7:41 AM PDTFlash Flood WarningVEFSan Bernardino3 hr
Aug 3, 2:00 PM PDTFlash Flood WarningVEFSan Bernardino3 hr

Nearby

Flash Flood Warnings in California, 2017Every flash flood warning in 2017

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.