Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 55, NWS Las Vegas, NV

July 23, 2012San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 23, 2012, 11:47 AM PDT for San Bernardino County, California. It was in force for 2 hr. 1 report 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
Jul 23, 2012, 11:47 AM PDT (18:47 UTC)
Expired
Jul 23, 2012, 2:05 PM PDT
In force
2 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), 62 km from the middle of the area, began a volume at 18:49 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
Jul 23, 12:30 PM PDTFLASH FLOOD8 Wsw Mountain Pass, CATIME OF OCCURRENCE WAS ESTIMATED FROM RADAR. ONGOING FLASH FLOODING WAS OBSERVED ALONG CIMA ROAD JUST SOUTH OF INTERSTATE 15 DURING STORM SURVEY AT 220 PM. 10-12 SIGNIFICANT DEBRIS FLOWS WERE OBSERVED ALONG CIMA ROAD 3 TO 5 MILES SOUTH OF INTERSTATE 15...SOME

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 12:00Z, 6.8 hours before the alert went out and 106 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 2012-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 177 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 2012-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 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
177 J/kg
Mixed-layer CIN
-137 J/kg
Mixed-layer LCL
2252 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
-22 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.

880 
WGUS55 KVEF 231847
FFWVEF
CAC071-232145-
/O.NEW.KVEF.FF.W.0055.120723T1847Z-120723T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
1147 AM PDT MON JUL 23 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 245 PM PDT.

* AT 1141 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM THUNDERSTORMS ALONG A LINE EXTENDING FROM 14
  MILES NORTHWEST OF CIMA TO 9 MILES SOUTH OF NIPTON AND IVANPAH
  ROADS...OR ALONG A LINE EXTENDING FROM 14 MILES NORTHWEST OF CIMA
  TO 11 MILES NORTHEAST OF CIMA. THE STORMS PRODUCING FLASH FLOODING
  WERE NEARLY STATIONARY.

* LOCATIONS IMPACTED INCLUDE...
  NIPTON...CIMA...MORNINGSTAR MINE AND IVANPAH ROADS AND NIPTON.

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 3547 11559 3545 11545 3549 11543 3551 11527
      3544 11518 3518 11549 3538 11585

$$

JH
2 follow-up statements
160 
WGUS75 KVEF 231939
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1239 PM PDT MON JUL 23 2012

CAC071-232145-
/O.CON.KVEF.FF.W.0055.000000T0000Z-120723T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
1239 PM PDT MON JUL 23 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 245 PM PDT FOR 
NORTHEAST SAN BERNARDINO COUNTY...

AT 1233 PM PDT...THUNDERSTORMS THAT PROMPTED THE FLASH FLOOD WARNING 
HAVE WEAKENED BUT RUNOFF FROM THE HEAVY RAIN EARLIER WILL STILL 
LIKELY CREATE FLASH FLOODING. IN ADDITION...MORE STORMS WERE 
APPROACHING THE WARNED AREA. 

LOCATIONS IMPACTED INCLUDE...
NIPTONCIMA...MORNINGSTAR MINE AND IVANPAH ROADS AND NIPTON.

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 3547 11559 3545 11545 3549 11543 3551 11527
      3544 11518 3518 11549 3538 11585

$$

JH
904 
WGUS75 KVEF 232105
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
205 PM PDT MON JUL 23 2012

CAC071-232115-
/O.CAN.KVEF.FF.W.0055.000000T0000Z-120723T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
205 PM PDT MON JUL 23 2012

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

THERE HAS BEEN NO RAIN FOR AWHILE FROM CIMA UP TO INTERSTATE 15 AND 
UP TO NIPTON AND NO REPORTS OF FLOODING SO THE WARNING HAS BEEN 
CANCELLED.

LAT...LON 3547 11559 3545 11545 3549 11543 3551 11527
      3544 11518 3518 11549 3538 11585

$$

JH

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 23, 11:17 AM PDTAreal Flood AdvisoryVEFInyo49 min
Jul 23, 12:05 PM PDTFlash Flood WarningVEFInyo115 min
Jul 23, 12:12 PM PDTSevere Thunderstorm WarningVEFSan Bernardino48 min
Jul 23, 12:18 PM PDTFlash Flood WarningVEFSan Bernardino117 min
Jul 23, 1:54 PM PDTSevere Thunderstorm WarningVEFSan Bernardino66 min

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.