Alert archive / California / Flash Flood Warnings in 2018

Flash Flood Warning 52, NWS Las Vegas, NV

July 13, 2018San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 13, 2018, 2:48 PM PDT for San Bernardino County, California. It was in force for 3 hr. 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 13, 2018, 2:48 PM PDT (21:48 UTC)
Expired
Jul 13, 2018, 5:45 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), 102 km from the middle of the area, began a volume at 21:49 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.

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 9.8 hours before the alert went out and 192 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°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.

168 
WGUS55 KVEF 132148
FFWVEF
CAC071-140045-
/O.NEW.KVEF.FF.W.0052.180713T2148Z-180714T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Las Vegas has issued a

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

* Until 545 PM PDT.

* At 247 PM PDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is expected to
  begin shortly.

* Some locations that will experience flooding include...
  Needles.

This includes Interstate 40 in California between mile markers 138
and 152.
 
LAT...LON 3484 11480 3491 11463 3487 11464 3484 11459
      3483 11458 3477 11456 3473 11451 3467 11465

$$

AW
2 follow-up statements
378 
WGUS75 KVEF 132319
FFSVEF

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

CAC071-140045-
/O.CON.KVEF.FF.W.0052.000000T0000Z-180714T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
419 PM PDT FRI JUL 13 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM PDT FOR
EASTERN SAN BERNARDINO COUNTY...

At 419 PM PDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area.  Flash flooding is expected to begin
shortly.

Some locations that will experience flooding include...
Needles.

This includes Interstate 40 in California between mile markers 138
and 152.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3484 11480 3491 11463 3487 11464 3484 11459
      3483 11458 3477 11456 3473 11451 3467 11465

$$

AW
270 
WGUS75 KVEF 140036
FFSVEF

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

CAC071-140045-
/O.EXP.KVEF.FF.W.0052.000000T0000Z-180714T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
536 PM PDT FRI JUL 13 2018

...THE FLASH FLOOD WARNING FOR EASTERN SAN BERNARDINO COUNTY WILL
EXPIRE AT 545 PM PDT...

Flood waters have receded. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 3484 11480 3491 11463 3487 11464 3484 11459
      3483 11458 3477 11456 3473 11451 3467 11465

$$

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, 11:39 AM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 13, 1:06 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Jul 13, 2:17 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.