Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 64, NWS Las Vegas, NV

July 30, 2012San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 30, 2012, 12:38 PM PDT for San Bernardino County, California. It was in force for 112 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
Jul 30, 2012, 12:38 PM PDT (19:38 UTC)
Expired
Jul 30, 2012, 2:30 PM PDT
In force
112 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), 78 km from the middle of the area, began a volume at 19:38 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, 7.6 hours before the alert went out and 129 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 2012-07-30Temperature 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 12:00Z on 2012-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2888 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
63 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.

113 
WGUS55 KVEF 301938
FFWVEF
CAC071-302130-
/O.NEW.KVEF.FF.W.0064.120730T1938Z-120730T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
1238 PM PDT MON JUL 30 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 230 PM PDT.

* AT 1232 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM NEAR CIMA. THE STORM 
PRODUCING   VERY HEAVY RAIN WAS MOVING WEST AT 10 MPH..

* LOCATIONS IMPACTED INCLUDE...CIMA AND SOUTH ALONG KELSO CIMA ROAD 
TO THE MACEDONIA CANYON ROAD TURNOFF. A LOW WATER CROSSING JUST 
SOUTH OF CIMA IS VERY SUSCEPTIBLE TO FLOODING...AND IS LIKELY TO BE 
IMPACTED BY THIS STORM EVEN AS IT MOVES WEST AS RUNOFF TYPICALLY 
DRAINS TO THIS AREA.

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 BY USING THE TWITTER HASHTAG...
NWSVEGAS.

&&

LAT...LON 3527 11558 3522 11542 3517 11543 3516 11554

$$
KENNEDY
2 follow-up statements
533 
WGUS75 KVEF 302006
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
106 PM PDT MON JUL 30 2012

CAC071-302130-
/O.CON.KVEF.FF.W.0064.000000T0000Z-120730T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
106 PM PDT MON JUL 30 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 PM PDT FOR
CENTRAL SAN BERNARDINO COUNTY...

AT 100 PM PDT...THUNDERSTORMS HAVE DIMINISHED OVER THE WARNED 
AREA AND CONTINUE TO MOVE SLOWLY TO THE SOUTHEAST...HOWEVER...RADAR 
ESTIMATES INDICATE A SIGNIFICANT AMOUNT OF PRECIPITATION OCCURRED 
OVER A BASIN WHICH DRAINS TO A KNOWN LOW WATER CROSSING LONG KELSO 
CIMA ROAD JUST SOUTH OF CIMA...AND FLASH FLOODING IS LIKELY STILL 
OCCURRING.

LOCATIONS IMPACTED INCLUDE...CIMA AND SOUTH ALONG KELSO CIMA ROAD TO 
THE MACEDONIA CANYON ROAD TURNOFF. 

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 3527 11558 3522 11542 3517 11543 3516 11554

$$
KENNEDY
811 
WGUS75 KVEF 302126
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
226 PM PDT MON JUL 30 2012

CAC071-302131-
/O.EXP.KVEF.FF.W.0064.000000T0000Z-120730T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.IO/
SAN BERNARDINO CA-
226 PM PDT MON JUL 30 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 230 PM PDT FOR CENTRAL SAN 
BERNARDINO COUNTY...

HEAVY RAINFALL HAS NOT FALLEN OVER THE WARNED AREA AND JUST WEST OF 
CIMA DURING THE PAST 50 MINUTES...AND ANY FLOOD WATERS IMPACTING 
CIMA ROAD AND KELSO CIMA ROAD SOUTH DOWN TO ELORA SHOULD BE 
RECEDING. 
THE FLASH FLOOD WARNING WILL BE ALLOWED TO EXPIRE AT 230 PM PDT. 

LAT...LON 3527 11558 3522 11542 3517 11543 3516 11554

$$

KENNEDY

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 9:00 PM PDTFlash Flood WatchVEFSan Bernardino25 hr
Jul 30, 11:53 AM PDTFlash Flood WarningVEFSan Bernardino112 min
Jul 30, 1:24 PM PDTFlash Flood WarningVEFSan Bernardino111 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.