Alert archive / California / Flash Flood Warnings in 2018

Flash Flood Warning 48, NWS Las Vegas, NV

July 13, 2018San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 13, 2018, 11:39 AM PDT for San Bernardino County, California. It was in force for 3 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 13, 2018, 11:39 AM PDT (18:39 UTC)
Expired
Jul 13, 2018, 2:45 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), 80 km from the middle of the area, began a volume at 18:41 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 13, 12:45 PM PDTFLASH FLOOD7 W Nipton, CAINTERSECTION BETWEEN NIPTON ROAD AND IVANPAH ROAD WASHED OUT DUE TO FLOODING. TIME ESTIMATED FROM RADAR.

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, 6.7 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 2018-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 358 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 12:00Z on 2018-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
358 J/kg
Mixed-layer CIN
-87 J/kg
Mixed-layer LCL
1523 m above ground
0-6 km bulk shear
2 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
-2 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

066 
WGUS55 KVEF 131839
FFWVEF
CAC071-132145-
/O.NEW.KVEF.FF.W.0048.180713T1839Z-180713T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
1139 AM PDT FRI JUL 13 2018

The National Weather Service in Las Vegas has issued a

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

* Until 245 PM PDT.

* At 1138 AM PDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to one inch of rain has
  already fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Cima, Kelso, Nipton and Nipton And Ivanpah Roads. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 3510 11575 3551 11541 3549 11525 3519 11540
      3490 11566

$$

AW
2 follow-up statements
422 
WGUS75 KVEF 131952
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1252 PM PDT FRI JUL 13 2018

CAC071-132145-
/O.CON.KVEF.FF.W.0048.000000T0000Z-180713T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
1252 PM PDT FRI JUL 13 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 245 PM PDT FOR
NORTH CENTRAL SAN BERNARDINO COUNTY...

At 1251 PM PDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Up to one inch of rain has already
fallen. Flash flooding is expected to begin shortly.

Some locations that will experience flooding include...
Cima, Kelso, Nipton and Nipton And Ivanpah Roads. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 3510 11575 3551 11541 3549 11525 3519 11540
      3490 11566

$$

AW
775 
WGUS75 KVEF 132135
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
235 PM PDT FRI JUL 13 2018

CAC071-132145-
/O.EXP.KVEF.FF.W.0048.000000T0000Z-180713T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
235 PM PDT FRI JUL 13 2018

...THE FLASH FLOOD WARNING FOR NORTH CENTRAL SAN BERNARDINO COUNTY
WILL EXPIRE AT 245 PM PDT...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 3510 11575 3551 11541 3549 11525 3519 11540
      3490 11566

$$

AW

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 12, 5:44 PM PDTFlash Flood WarningVEFInyo3 hr
Jul 13, 1:06 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Jul 13, 2:17 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 13, 2:48 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 13, 3:23 PM PDTFlash Flood WarningVEFSan Bernardino3 hr

Nearby

Flash Flood Warnings in California, 2018Every flash flood warning in 2018

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.