Alert archive / California / Flash Flood Warnings in 2011

Flash Flood Warning 90, NWS Las Vegas, NV

September 13, 2011San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Sep 13, 2011, 9:09 AM 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
Sep 13, 2011, 9:09 AM PDT (16:09 UTC)
Expired
Sep 13, 2011, 11:00 AM 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), 115 km from the middle of the area, began a volume at 16:12 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, 4.2 hours before the alert went out and 186 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 2011-09-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 239 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 2011-09-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 75 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
239 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
1707 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
136 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

905 
WGUS55 KVEF 131609
FFWVEF
CAC071-131800-
/O.NEW.KVEF.FF.W.0090.110913T1609Z-110913T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
909 AM PDT TUE SEP 13 2011

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 1100 AM PDT.

* AT 903 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
VERY HEAVY RAIN FROM A THUNDERSTORM ALONG ROUTE 66 OR NATIONAL 
TRAILS HIGHWAY BETWEEN AMBOY AND NORTH OF ESSEX TO JUST NORTH OF 
INTERSTATE 40 IN EAST CENTRAL SAN BERNARDINO COUNTY.

* LOCATIONS IMPACTED INCLUDE...NATIONAL TRAILS HIGHWAY BETWEEN AMBOY 
AND INTERSTATE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED ON AREA ROADWAYS...AROUND UNDERPASSES...
AND IN NORMALLY DRY WASHES AND LOW LYING AREAS. FLASH FLOODING IS
NATURES NUMBER ONE KILLER. 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 TWITTER #NWSVEGAS.

&&

LAT...LON 3490 11512 3483 11505 3463 11531 3450 11548
      3456 11558

$$
KENNEDY
2 follow-up statements
021 
WGUS75 KVEF 131742
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1042 AM PDT TUE SEP 13 2011

CAC071-131800-
/O.CON.KVEF.FF.W.0090.000000T0000Z-110913T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
1042 AM PDT TUE SEP 13 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1100 AM PDT FOR EAST
CENTRAL SAN BERNARDINO COUNTY...

AT 1037 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A MODERATE RAIN FALLING OVER THE WARNED AREA WHERE RADAR 
HAD ESTIMATED UP TO 4 INCHES INCHES OF RAINFALL HAD FALLEN EARLIER 
THIS MORNING.  

LOCATIONS IMPACTED INCLUDE... ROUTE 66 OR NATIONAL TRAILS HIGHWAY 
BETWEEN AMBOY AND NORTH OF ESSEX TO JUST NORTH OF INTERSTATE 40 IN 
EAST CENTRAL SAN BERNARDINO COUNTY.

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 TWITTER #NWSVEGAS.

&&

LAT...LON 3490 11512 3483 11505 3463 11531 3450 11548
      3456 11558

$$
KENNEDY
945 
WGUS75 KVEF 131759
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1059 AM PDT TUE SEP 13 2011

CAC071-131808-
/O.EXP.KVEF.FF.W.0090.000000T0000Z-110913T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
1059 AM PDT TUE SEP 13 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 1100 AM PDT FOR EAST 
CENTRAL SAN BERNARDINO COUNTY...

RAINFALL RATES HAVE DECREASED SIGNIFICANTLY SINCE 1000 AM 
PDT...ALONG WITH THE THREAT OF FLASH FLOODING ALONG HIGHWAY 66 IN 
EASTERN SAN BERNARDINO COUNTY. THE FLASH FLOOD WARNING WILL BE 
ALLOWED TO EXPIRE AT 1100 AM.

LAT...LON 3490 11512 3483 11505 3463 11531 3450 11548
      3456 11558

$$
KENNEDY

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 13, 3:36 AM PDTFlash Flood WatchVEFSan Bernardino15 hr
Sep 13, 5:46 AM PDTAreal Flood AdvisoryVEFSan Bernardino119 min
Sep 13, 6:31 AM PDTFlash Flood WarningVEFSan Bernardino86 min
Sep 13, 8:01 AM PDTFlash Flood WarningVEFSan Bernardino119 min
Sep 13, 9:56 AM PDTFlash Flood WarningVEFSan Bernardino83 min
Sep 13, 10:22 AM PDTFlash Flood WarningVEFSan Bernardino113 min
Sep 13, 11:09 AM PDTFlash Flood WarningVEFSan Bernardino27 min

Nearby

Flash Flood Warnings in California, 2011Every flash flood warning in 2011

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.