Alert archive / California / Flash Flood Warnings in 2018

Flash Flood Warning 2, NWS Las Vegas, NV

July 8, 2018San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 8, 2018, 3:25 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 8, 2018, 3:25 PM PDT (22:25 UTC)
Expired
Jul 8, 2018, 6:30 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), 98 km from the middle of the area, began a volume at 22:25 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, 10.4 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.

Skew-T log-pSkew-T log-p diagram, Las Vegas, NV at 12:00Z on 2018-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 166 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 2018-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 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
166 J/kg
Mixed-layer CIN
-308 J/kg
Mixed-layer LCL
2845 m above ground
0-6 km bulk shear
1 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
9 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

461 
WGUS55 KVEF 082225
FFWVEF
CAC071-090130-
/O.NEW.KVEF.FF.W.0002.180708T2225Z-180709T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
325 PM PDT SUN JUL 8 2018

The National Weather Service in Las Vegas has issued a

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

* Until 630 PM PDT.

* At 323 PM PDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to one inch of rain has
  already fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Essex, Highway 95, National Trails Highway, Essex Road, Goffs Road 
  and I-40. 

This includes Interstate 40 in California between mile markers 95 and
133.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3494 11469 3453 11510 3454 11540 3485 11543
      3515 11483

$$
CK
2 follow-up statements
744 
WGUS75 KVEF 082355
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
455 PM PDT SUN JUL 8 2018

CAC071-090130-
/O.CON.KVEF.FF.W.0002.000000T0000Z-180709T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
455 PM PDT SUN JUL 8 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM PDT FOR
EAST CENTRAL SAN BERNARDINO COUNTY...

At 446 PM PDT, Doppler radar indicated thunderstorms producing heavy 
rainfall have moved out of the warned area. Though, up to one inch 
to one and half inches of rain has fallen and flash flooding is 
expected to begin shortly.

Some locations that will experience flooding include...
Essex, portions of Highway 95, National Trails Highway, Essex Road, 
and Goffs Road. 

This includes Interstate 40 in California between mile markers 95 and
133.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3494 11469 3453 11510 3454 11540 3485 11543
      3515 11483

$$
CK
679 
WGUS75 KVEF 090122
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
622 PM PDT SUN JUL 8 2018

CAC071-090131-
/O.EXP.KVEF.FF.W.0002.000000T0000Z-180709T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
622 PM PDT SUN JUL 8 2018

...THE FLASH FLOOD WARNING FOR EAST CENTRAL SAN BERNARDINO COUNTY
WILL EXPIRE AT 630 PM PDT...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Therefore, the warning will be allowed to expire. Please 
continue to heed any remaining road closures.

LAT...LON 3494 11469 3453 11510 3454 11540 3485 11543
      3515 11483

$$

AB

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 8, 12:15 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Jul 8, 12:40 PM PDTAreal Flood AdvisoryVEFSan Bernardino2 hr
Jul 8, 3:02 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 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.