Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 33, NWS Las Vegas, NV

July 24, 2017San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 24, 2017, 6:54 PM PDT for San Bernardino County, California. It was in force for 3 hr. 3 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
Jul 24, 2017, 6:54 PM PDT (01:54 UTC)
Expired
Jul 24, 2017, 10:00 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), 118 km from the middle of the area, began a volume at 01:55 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 24, 9:00 PM PDTFLASH FLOOD8 Sw Essex, CASAN BERNARDINO COUNTY PUBLIC WORKS REPORTS 14 TIMBER BRIDGES IN THE ESSEX/DANBY AREA ALONG NATIONAL TRAILS HIGHWAY SUSTAINED DAMAGE DUE TO FLOODING. TIME ESTIMATED.
Jul 24, 9:11 PM PDTFLASH FLOOD1 Ssw Amboy, CACHP REPORTED RDWY WASHED OUT DUE TO FLOODING.
Jul 24, 9:11 PM PDTFLASH FLOODAmboy, CACHP REPORTED RDWY WASHED OUT DUE TO FLOODING.

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, 1.9 hours before the alert went out and 187 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 2017-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 183 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 00:00Z on 2017-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 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
183 J/kg
Mixed-layer CIN
-90 J/kg
Mixed-layer LCL
2329 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
51 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

179 
WGUS55 KVEF 250154
FFWVEF
CAC071-250500-
/O.NEW.KVEF.FF.W.0033.170725T0154Z-170725T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
654 PM PDT MON JUL 24 2017

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  South central San Bernardino County in southern California...

* Until 1000 PM PDT

* At 653 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain over Route 66 between Fenner and Goffs, over National 
  Trails Highway near Essex, and over Amboy Road between Amboy and 
  Sheep Hole Pass. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Essex and Amboy. 

LAT...LON 3500 11506 3479 11504 3412 11576 3461 11577

$$

Morgan
3 follow-up statements
227 
WGUS75 KVEF 250255
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
755 PM PDT MON JUL 24 2017

CAC071-250500-
/O.CON.KVEF.FF.W.0033.000000T0000Z-170725T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
755 PM PDT MON JUL 24 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1000 PM PDT FOR
SOUTH CENTRAL SAN BERNARDINO COUNTY...

At 753 PM PDT, Doppler radar indicated thunderstorms still producing 
heavy rain over National Trails Highway between Amboy and Essex, and 
over Route 66 between Fenner and Goffs. Flash flooding is likely 
occurring and expected to continue.

Some locations that will experience flooding include...
Essex and Amboy. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3500 11506 3479 11504 3412 11576 3461 11577

$$

Morgan
328 
WGUS75 KVEF 250348
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
848 PM PDT MON JUL 24 2017

CAC071-250500-
/O.CON.KVEF.FF.W.0033.000000T0000Z-170725T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
848 PM PDT MON JUL 24 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1000 PM PDT FOR
SOUTH CENTRAL SAN BERNARDINO COUNTY...

At 846 PM PDT, Doppler radar indicated a thunderstorm with 
torrential rain between National Trails Highway and Interstate 40 
moving east toward Essex. Very heavy rain had already fallen along 
Amboy Road and National Trails Highway near Amboy. Flash flooding is 
likely occurring, and more is expected when the storm reaches Essex.

Some locations that will experience flooding include...
Essex and Amboy. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3500 11506 3479 11504 3412 11576 3461 11577

$$

Morgan
602 
WGUS75 KVEF 250455
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
955 PM PDT MON JUL 24 2017

CAC071-250503-
/O.EXP.KVEF.FF.W.0033.000000T0000Z-170725T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
955 PM PDT MON JUL 24 2017

...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL SAN BERNARDINO COUNTY
WILL EXPIRE AT 1000 PM PDT...

Heavy rain was ending in the area from Amboy to Essex. Although no 
new flooding is expected, Amboy Road was reported to be flooded out 
and flooding is also possible on National Trails Highway. Please 
continue to heed any remaining road closures.

LAT...LON 3500 11506 3479 11504 3412 11576 3461 11577

$$

Morgan

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 6:30 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 24, 7:40 PM PDTFlash Flood WarningVEFSan Bernardino2 hr
Jul 24, 11:59 PM PDTFlash Flood WatchVEFSan Bernardino20 hr
Jul 25, 11:06 AM PDTFlash Flood WarningVEFSan Bernardino6 hr
Jul 25, 11:39 AM PDTFlash Flood WarningVEFInyo3 hr
Jul 25, 1:28 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 25, 4:07 PM PDTFlash Flood WarningVEFSan Bernardino3 hr

Nearby

Flash Flood Warnings in California, 2017Every flash flood warning in 2017

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.