Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 168, NWS Las Vegas, NV

August 22, 2012San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Aug 22, 2012, 7:29 PM PDT for San Bernardino County, California. It was in force for 111 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
Aug 22, 2012, 7:29 PM PDT (02:29 UTC)
Expired
Aug 22, 2012, 9:20 PM PDT
In force
111 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), 87 km from the middle of the area, began a volume at 02:30 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 00:00Z, 2.5 hours before the alert went out and 174 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 00:00Z on 2012-08-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 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 00:00Z on 2012-08-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 square meters per square second.193958Sfc1 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
7 J/kg
Mixed-layer CIN
-273 J/kg
Mixed-layer LCL
880 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
-117 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

855 
WGUS55 KVEF 230229
FFWVEF
CAC071-230515-
/O.NEW.KVEF.FF.W.0168.120823T0229Z-120823T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
729 PM PDT WED AUG 22 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL SAN BERNARDINO COUNTY IN SOUTHERN CALIFORNIA...

* UNTIL 1015 PM PDT.

* NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED BETWEEN 2 AND 3 
  INCHES OF RAIN FELL EARLIER THIS AFTERNOON OVER BASINS IN EASTERN 
  SAN BERNARDINO COUNTY WHICH RUN DOWN A WASH THAT CROSSES HIGHWAY 
  95 NEAR MILE MARKER  61...JUST NORTH OF INTERSTATE 40. IT TAKES
  SEVERAL HOURS FOR FLOOD WATERS TO MAKE THEIR WAY DOWN THE WASH
  BUT IT WILL LIKELY MAKE HIGHWAY 95 IMPASSABLE SOMETIME BETWEEN
  730 PM AND 10 PM.

* LOCATIONS IMPACTED INCLUDE...
  HIGHWAY 95 NEAR MILE MARKER 61 WEST OF NEEDLES AND JUST NORTH
  OF I-40.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED IN WASHES...LOW WATER CROSSINGS AND ON
AREA ROADWAYS. FLASH FLOODING IS NATURES NUMBER ONE KILLER. TO ESCAPE
RISING WATER...MOVE TO HIGHER GROUND. NEVER TRY TO CROSS A FLOODED
ROADWAY OR WALK THROUGH FLOODWATERS. TURN AROUND...DONT DROWN!

REPORT FLOODING BY POSTING YOUR REPORT TO THE LAS VEGAS NATIONAL
WEATHER SERVICE FACEBOOK PAGE...OR BY USING THE TWITTER HASHTAG...
NWSVEGAS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS EVEN HARDER TO SEE WATER
COVERING THE ROADWAY OR IN LOW WATER CROSSINGS.

&&

LAT...LON 3496 11490 3491 11474 3490 11473 3488 11475
      3490 11494

$$

JA
1 follow-up statement
963 
WGUS75 KVEF 230420
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
920 PM PDT WED AUG 22 2012

CAC071-230421-
/O.CAN.KVEF.FF.W.0168.000000T0000Z-120823T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
920 PM PDT WED AUG 22 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EAST CENTRAL SAN
BERNARDINO COUNTY...

CALIFORNIA HIGHWAY PATROL REPORTED THAT NO FLOODING WAS OBSERVED 
ALONG GOFFS ROAD WEST OF HIGHWAY 95 AND NORTH OF I-40. THIS IS 
UPSTREAM FROM WHERE THE SACRAMENTO WASH CROSSES HIGHWAY 95 NEAR
MILE MARKER 61. IT APPEARS THE THREAT OF FLASH FLOODING FOR THIS 
AREA HAS DIMINISHED AND THE FLASH FLOOD WARNING HAS BEEN CANCELLED.

LAT...LON 3496 11490 3491 11474 3490 11473 3488 11475
      3490 11494

$$

JA

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 22, 5:25 PM PDTFlash Flood WarningVEFInyo2 hr

Nearby

Flash Flood Warnings in California, 2012Every flash flood warning in 2012

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.