Alert archive / California / Flash Flood Warnings in 2016

Flash Flood Warning 52, NWS Las Vegas, NV

August 1, 2016San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Aug 1, 2016, 4:51 PM 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
Aug 1, 2016, 4:51 PM PDT (23:51 UTC)
Expired
Aug 1, 2016, 7:45 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), 113 km from the middle of the area, began a volume at 23:55 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
Aug 1, 6:30 PM PDTFLASH FLOOD2 Ne Essex, CACA HIGHWAY PATROL REPORTS WATER AND DEBRIS IN ROADWAY AT GOFFS ROAD AND NATIONAL TRAILS HIGHWAY. TIME OF OCCURRENCE UNKNOWN/ESTIMATED.

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, 11.9 hours before the alert went out and 196 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 2016-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 365 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 2016-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -22 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
365 J/kg
Mixed-layer CIN
-262 J/kg
Mixed-layer LCL
1839 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-22 m²/s²
0-3 km storm-relative helicity
27 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

407 
WGUS55 KVEF 012351
FFWVEF
CAC071-020245-
/O.NEW.KVEF.FF.W.0052.160801T2351Z-160802T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
451 PM PDT MON AUG 1 2016

THE NATIONAL WEATHER SERVICE IN LAS VEGAS  HAS ISSUED A

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

* UNTIL 745 PM PDT

* AT 448 PM PDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
  HEAVY RAIN NEAR ESSEX AND WEST OF NEEDLES. FLASH FLOODING IS
  EXPECTED TO BEGIN SHORTLY ON PARTS OF ESSEX, GOFFS AND NATIONAL
  TRAILS HIGHWAY. FLASH FLOODING IS ALSO POSSIBLE NEAR THE
  INTERSECTION OF INTERSTATE 40 AND HIGHWAY 95.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  HIGHWAY 95 AT MILE MARKER 29...NEEDLES...HIGHWAY 95 AND I-40 AND
  ESSEX.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO CROSS FLOODED
ROADS. FIND AN ALTERNATE ROUTE.

&&

LAT...LON 3423 11567 3472 11568 3487 11482 3496 11483
      3493 11476 3490 11463 3487 11464 3484 11459
      3477 11456 3474 11452 3420 11459

$$

BP
2 follow-up statements
442 
WGUS75 KVEF 020104
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
604 PM PDT MON AUG 1 2016

CAC071-020245-
/O.CON.KVEF.FF.W.0052.000000T0000Z-160802T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
604 PM PDT MON AUG 1 2016

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM PDT FOR
SOUTHEASTERN SAN BERNARDINO COUNTY...

AT 603 PM PDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
HEAVY RAIN ACROSS THE WARNED AREA ARE BEGINNING TO WEAKEN. FLASH
FLOODING OF NORMALLY DRY WASHES WILL CONTINUE.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
HIGHWAY 95 AT MILE MARKER 29...NEEDLES...
HIGHWAY 95 AND I-40 AND ESSEX.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO CROSS FLOODED
ROADS. FIND AN ALTERNATE ROUTE.

&&

LAT...LON 3423 11567 3472 11568 3487 11482 3496 11483
      3493 11476 3490 11463 3487 11464 3484 11459
      3477 11456 3474 11452 3420 11459

$$

BP
527 
WGUS75 KVEF 020235
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
735 PM PDT MON AUG 1 2016

CAC071-020245-
/O.EXP.KVEF.FF.W.0052.000000T0000Z-160802T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
735 PM PDT MON AUG 1 2016

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN SAN BERNARDINO COUNTY
WILL EXPIRE AT 745 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 3423 11567 3472 11568 3487 11482 3496 11483
      3493 11476 3490 11463 3487 11464 3484 11459
      3477 11456 3474 11452 3420 11459

$$

BP

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 5:37 PM PDTAreal Flood AdvisoryVEFInyo3 hr
Aug 1, 1:54 PM PDTAreal Flood AdvisoryVEFInyo, San Bernardino3 hr
Aug 1, 2:29 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Aug 1, 2:47 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Aug 1, 3:44 PM PDTFlash Flood WarningVEFSan Bernardino3 hr

Nearby

Flash Flood Warnings in California, 2016Every flash flood warning in 2016

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.