Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 176, NWS Las Vegas, NV

September 3, 2012San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Sep 3, 2012, 7:42 PM PDT for San Bernardino County, California. It was in force for 3 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Sep 3, 2012, 7:42 PM PDT (02:42 UTC)
Expired
Sep 3, 2012, 10:45 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), 139 km from the middle of the area, began a volume at 02:42 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.

What was reported inside it

TimeReportWhereRemark
Sep 3, 8:08 PM PDTFLASH FLOOD18 Wsw Desert Hills, CACALIFORNIA HIGHWAY PATROL REPORTED THAT HIGHWAY 95 WAS CLOSED FROM APPROXIMATELY MILE MARKER 21 TO VIDAL JUNCTION DUE TO FLOODING AT MILE MARKER 29. THIS IS WHERE THE CHEMEHUEVI WASH CROSSES THE HIGHWAY.
Sep 3, 9:01 PM PDTFLASH FLOOD18 Wsw Desert Hills, CACALIFORNIA HIGHWAY PATROL HAS CLOSED HIGHWAY 95 DUE TO FLASH FLOODING AT MILE MARKER 29 SOUTH OF NEEDLES. HIGHWAY PATROL STATED THAT THE WATER WAS TOO DEEP FOR CARS TO DRIVE THROUGH AND THERE WAS DEBRIS ALL OVER THE ROAD.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Las Vegas, NV (KVEF), launched 00:00Z, 2.7 hours before the alert went out and 228 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 2012-09-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2012-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
5554 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
16 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.

454 
WGUS55 KVEF 040242
FFWVEF
CAC071-040545-
/O.NEW.KVEF.FF.W.0176.120904T0242Z-120904T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
742 PM PDT MON SEP 3 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 1045 PM PDT.

* AT 730 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM OVER EXTREME SOUTHEASTERN SAN
  BERNARDINO COUNTY...OR 19 MILES WEST OF LAKE HAVASU CITY. THE STORM
  PRODUCING VERY HEAVY RAIN WAS NEARLY STATIONARY OVER THE           
  CHEMEHUEVI WASH.

* LOCATIONS IMPACTED INCLUDE...CHEMEHUEVI WASH AND NUMEROUS SMALLER
  WASHES THAT FEED INTO THE CHEMEHUEVI WASH. HIGHWAY 95...SPECIFICALLY
  NEAR MILE MARKER 29 WHERE THE CHEMEHUEVI WASH CROSSES HIGHWAY 95 BETWEEN
  NEEDLES AND VIDAL JUNCTION. 

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.

&&

LAT...LON 3453 11476 3458 11464 3455 11457 3444 11460
      3445 11448 3444 11448 3442 11461 3436 11466
      3435 11476

$$

PIERCE
2 follow-up statements
199 
WGUS75 KVEF 040423
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
923 PM PDT MON SEP 3 2012

CAC071-040545-
/O.CON.KVEF.FF.W.0176.000000T0000Z-120904T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
923 PM PDT MON SEP 3 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM PDT FOR EAST
CENTRAL SAN BERNARDINO COUNTY...

AT 916 PM PDT...LOCAL LAW ENFORCEMENT OFFICIALS CLOSED A PORTION OF 
HIGHWAY 95 SOUTH OF NEEDLES...NEAR HAVASU LAKE ROAD EARLIER IN THE 
EVENING. THE HIGHWAY HAS ALSO BEEN CLOSED AT STATE ROUTE 62 AT VIDAL 
JUNCTION. 

THUNDERSTORMS HAVE WEAKENED IN THE AREA...HOWEVER RUNOFF FROM 
EARLIER RAINFALL WILL CONTINUE IN THE CHEMEHUEVI WASH AND OTHER 
NUMEROUS WASHES THAT CROSS HIGHWAY 95.   

LOCATIONS IMPACTED INCLUDE...HIGHWAY 95 BETWEEN NEEDLES AND VIDAL 
JUNCTION. 

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.

&&

LAT...LON 3453 11476 3458 11464 3455 11457 3444 11460
      3445 11448 3444 11448 3442 11461 3436 11466
      3435 11476

$$

PIERCE
587 
WGUS75 KVEF 040542
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1042 PM PDT MON SEP 3 2012

CAC071-040548-
/O.EXP.KVEF.FF.W.0176.000000T0000Z-120904T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
1042 PM PDT MON SEP 3 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 1045 PM PDT FOR EAST
CENTRAL SAN BERNARDINO COUNTY...

RUNOFF IN THE CHEMEHUEVI WASH AT HIGHWAY 95 SOUTH OF NEEDLES WILL 
CONTINUE TO RECEDE AS RAINFALL HAS NOT OCCURRED IN THE DRAINAGE 
BASIN SINCE 830 PM PDT. THE FLASH FLOOD WARNING WILL EXPIRE AT 1045 
PM PDT.

LAT...LON 3453 11476 3458 11464 3455 11457 3444 11460
      3445 11448 3444 11448 3442 11461 3436 11466
      3435 11476

$$

PIERCE

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 3, 6:08 PM PDTSevere Thunderstorm WarningVEFSan Bernardino37 min
Sep 3, 6:43 PM PDTAreal Flood AdvisoryVEFSan Bernardino63 min
Sep 4, 2:00 PM PDTFlash Flood WarningVEFSan Bernardino65 min
Sep 4, 3:44 PM PDTFlash Flood WarningVEFSan Bernardino2 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.