Alert archive / California / Flash Flood Warnings in 2018

Flash Flood Warning 41, NWS Las Vegas, NV

July 12, 2018San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 12, 2018, 3:03 PM PDT for San Bernardino County, California. It was in force for 104 min. 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 12, 2018, 3:03 PM PDT (22:03 UTC)
Expired
Jul 12, 2018, 4:47 PM PDT
In force
104 min
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), 88 km from the middle of the area, began a volume at 22:04 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, 10.1 hours before the alert went out and 168 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 2018-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 627 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 12:00Z on 2018-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -15 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
627 J/kg
Mixed-layer CIN
-87 J/kg
Mixed-layer LCL
1700 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
-15 m²/s²
0-3 km storm-relative helicity
48 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

008 
WGUS55 KVEF 122203
FFWVEF
CAC071-130100-
/O.NEW.KVEF.FF.W.0041.180712T2203Z-180713T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
303 PM PDT THU JUL 12 2018

The National Weather Service in Las Vegas has issued a

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

* Until 600 PM PDT.

* At 302 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain over Route 66 between Fenner and Goffs. Flash flooding 
  is expected to begin shortly.

* Flash flooding will remain over mainly rural areas of central San
  Bernardino County.

This includes Interstate 40 in California between mile markers 109
and 121.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3501 11493 3483 11496 3478 11518 3498 11517

$$

Morgan
2 follow-up statements
113 
WGUS75 KVEF 122258
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
358 PM PDT THU JUL 12 2018

CAC071-130100-
/O.CON.KVEF.FF.W.0041.000000T0000Z-180713T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
358 PM PDT THU JUL 12 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 600 PM PDT FOR
CENTRAL SAN BERNARDINO COUNTY...

At 357 PM PDT, Doppler radar indicated that rain was tapering off on 
Highway 66 between Fenner and Goffs. However, very heavy rain had 
fallen in the area, and roadway flooding is likely ongoing.

Flash flooding will remain over mainly rural areas of central San 
Bernardino County.

This includes Interstate 40 in California between mile markers 109
and 121.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3501 11493 3483 11496 3478 11518 3498 11517

$$

Morgan
282 
WGUS75 KVEF 122347
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
447 PM PDT THU JUL 12 2018

CAC071-122357-
/O.CAN.KVEF.FF.W.0041.000000T0000Z-180713T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
447 PM PDT THU JUL 12 2018

...THE FLASH FLOOD WARNING FOR CENTRAL SAN BERNARDINO COUNTY IS
CANCELLED...

The heavy rain has ended on Goffs Road between Fenner and Goffs. The 
California Highway Patrol reported that the road was closed due to 
flooding. Please continue to heed any remaining road closures.

LAT...LON 3501 11493 3483 11496 3478 11518 3498 11517

$$

Morgan

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 7:21 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Jul 12, 2:51 AM PDTFlash Flood WatchVEFInyo21 hr
Jul 12, 11:15 AM PDTFlash Flood WarningVEFSan Bernardino53 min
Jul 12, 11:26 AM PDTFlash Flood WarningVEFSan Bernardino65 min
Jul 12, 12:48 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 12, 1:50 PM PDTFlash Flood WarningVEFSan Bernardino110 min
Jul 12, 2:04 PM PDTFlash Flood WarningVEFInyo3 hr
Jul 12, 3:02 PM PDTFlash Flood WarningVEFSan Bernardino2 hr
Jul 12, 4:20 PM PDTFlash Flood WarningVEFSan Bernardino88 min
Jul 12, 4:51 PM PDTFlash Flood WarningVEFInyo3 hr
Jul 12, 4:56 PM PDTFlash Flood WarningVEFSan Bernardino2 hr

Nearby

Flash Flood Warnings in California, 2018Every flash flood warning in 2018

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.