Alert archive / California / Flash Flood Warnings in 2017
Flash Flood Warning 87, NWS Las Vegas, NV
NWS Las Vegas, NV issued this flash flood warning at Aug 11, 2017, 1:56 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 11, 2017, 1:56 PM PDT (20:56 UTC)
- Expired
- Aug 11, 2017, 5:00 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 Santa Ana Mts radar (KSOX), 154 km from the middle of the area, began a volume at 20:56 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 11, 2:22 PM PDT | FLASH FLOOD | 1 W Twentynine Palms, CA | CHP REPORTED WATER FLOWING ACROSS THE ROADWAY AT THE INTERSECTION OF HIGHWAY 62 AND MESQUITE SPRINGS ROAD. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
San Diego, CA (KNKX), launched 12:00Z, 8.9 hours before the alert went out and 184 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1427 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- -7 m²/s²
- 0-3 km storm-relative helicity
- -12 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
799
WGUS55 KVEF 112056
FFWVEF
CAC071-120000-
/O.NEW.KVEF.FF.W.0087.170811T2056Z-170812T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
156 PM PDT FRI AUG 11 2017
The National Weather Service in Las Vegas has issued a
* Flash Flood Warning for...
South central San Bernardino County in southern California...
* Until 500 PM PDT
* At 154 PM PDT, Doppler radar indicated thunderstorms producing
heavy rain across the Twentynine Palms area. Flash flooding is
expected to begin shortly.
* Some locations that will experience flooding include...
Twentynine Palms, Twentynine Palms Base, Amboy Road, Highway 62,
and Twentynine Palms Airport.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3407 11600 3408 11601 3408 11604 3410 11604
3412 11605 3412 11618 3433 11602 3421 11574
3403 11593 3403 11600
$$
AA2 follow-up statements
633
WGUS75 KVEF 112229
FFSVEF
Flash Flood Statement
National Weather Service Las Vegas NV
329 PM PDT FRI AUG 11 2017
CAC071-120000-
/O.CON.KVEF.FF.W.0087.000000T0000Z-170812T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
329 PM PDT FRI AUG 11 2017
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 PM PDT FOR
SOUTH CENTRAL SAN BERNARDINO COUNTY...
At 327 PM PDT, Doppler radar continued to indicate heavy rain across
the Twentynine Palms area. Flash flooding is already occurring along
portions of Highway 62 along with other local roads.
Some locations that will experience flooding include...
Twentynine Palms, Twentynine Palms Base and Twentynine Palms Airport.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3407 11600 3408 11601 3408 11604 3410 11604
3412 11605 3412 11618 3433 11602 3421 11574
3403 11593 3403 11600
$$
ASG430
WGUS75 KVEF 112356
FFSVEF
Flash Flood Statement
National Weather Service Las Vegas NV
456 PM PDT FRI AUG 11 2017
CAC071-120005-
/O.EXP.KVEF.FF.W.0087.000000T0000Z-170812T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
456 PM PDT FRI AUG 11 2017
...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL SAN BERNARDINO COUNTY
WILL EXPIRE AT 500 PM PDT...
The heavy rain has ended in the Twentynine Palms area. Flooding is
no longer expected to pose a threat, however standing water is
likely present on Highway 62 along with other nearby roads. Please
continue to heed any remaining road closures.
LAT...LON 3407 11600 3408 11601 3408 11604 3410 11604
3412 11605 3412 11618 3433 11602 3421 11574
3403 11593 3403 11600
$$
ASGThe office that day
Everything else NWS Las Vegas, NV issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 2:42 PM PDT | Severe Thunderstorm Warning | VEF | San Bernardino | 48 min |
| Aug 11, 2:47 PM PDT | Flash Flood Warning | VEF | San Bernardino | 3 hr |
| Aug 11, 3:51 PM PDT | Flash Flood Warning | VEF | San Bernardino | 3 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.