Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 121, NWS Las Vegas, NV

September 9, 2017San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Sep 9, 2017, 12:38 PM PDT for San Bernardino County, California. It was in force for 5 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
Sep 9, 2017, 12:38 PM PDT (19:38 UTC)
Expired
Sep 9, 2017, 5:30 PM PDT
In force
5 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), 87 km from the middle of the area, began a volume at 19:42 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
Sep 9, 2:37 PM PDTFLASH FLOOD7 Ssw Cima, CACHP CLOSED KELSO CIMA RD BETWEEN MORNING STAR RD TO KELBAKER RD 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 12:00Z, 7.6 hours before the alert went out and 135 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 2017-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 114 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 2017-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 square meters per square second.19395878Sfc1 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
114 J/kg
Mixed-layer CIN
-102 J/kg
Mixed-layer LCL
930 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

245 
WGUS55 KVEF 091938
FFWVEF
CAC071-100030-
/O.NEW.KVEF.FF.W.0121.170909T1938Z-170910T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
1238 PM PDT SAT SEP 9 2017

The National Weather Service in Las Vegas has issued a

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

* Until 530 PM PDT

* At 1235 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the Mojave Preserve. Flash flooding is expected 
  to begin shortly.

* Some locations that will experience flooding include...
  Mitchell Caverns, Cima, Kelso, Nipton And Ivanpah Roads, Hole In
  The Wall Campground, Mid Hills Campground, Nipton and Black Canyon
  Equestrian Campground.

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.

Remain alert for flooding even in locations not receiving rain.
Arroyos, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.

&&

LAT...LON 3514 11618 3534 11592 3545 11560 3545 11545
      3557 11535 3518 11486 3487 11483 3480 11543
      3473 11618

$$

Steele
3 follow-up statements
827 
WGUS75 KVEF 092105
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
205 PM PDT SAT SEP 9 2017

CAC071-100030-
/O.CON.KVEF.FF.W.0121.000000T0000Z-170910T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
205 PM PDT SAT SEP 9 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM PDT FOR
CENTRAL SAN BERNARDINO COUNTY...

At 203 PM PDT, Doppler radar indicated the strongest storms are now 
neat Mid Hills and Holl in the Wall Campgrounds. Flash flooding is 
expected to begin shortly if not already ongoing.

Some locations that will experience flooding include...
Mitchell Caverns, Cima, Kelso, Nipton And Ivanpah Roads, Hole In The
Wall Campground, Mid Hills Campground, Nipton and Black Canyon
Equestrian Campground.

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.

Remain alert for flooding even in locations not receiving rain.
Arroyos, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.

&&

LAT...LON 3514 11618 3534 11592 3545 11560 3545 11545
      3557 11535 3518 11486 3487 11483 3480 11543
      3473 11618

$$

Steele
616 
WGUS75 KVEF 092227
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
327 PM PDT SAT SEP 9 2017

CAC071-100030-
/O.CON.KVEF.FF.W.0121.000000T0000Z-170910T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
327 PM PDT SAT SEP 9 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM PDT FOR
CENTRAL SAN BERNARDINO COUNTY...

At 320 PM PDT, Doppler radar indicated heavy rain due to 
thunderstorms over the Mojave Preserve. CHP reported Kelso Cima Road 
closed between Morning Star and Kelbaker Road due to flooding. 
Travelers should remain alert to the dangers of heavy rain in hilly 
terrain and avoid driving through low lying areas where water covers 
the roadway.

Some locations that have or could experience flooding include...
Mitchell Caverns, Cima, Kelso, Nipton And Ivanpah Roads, Hole In The
Wall Campground, Mid Hills Campground, Nipton and Black Canyon
Equestrian Campground.

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.

Remain alert for flooding even in locations not receiving rain.
Arroyos, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3514 11618 3534 11592 3545 11560 3545 11545
      3557 11535 3518 11486 3487 11483 3480 11543
      3473 11618

$$

JS
574 
WGUS75 KVEF 100024
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
524 PM PDT SAT SEP 9 2017

CAC071-100033-
/O.EXP.KVEF.FF.W.0121.000000T0000Z-170910T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
524 PM PDT SAT SEP 9 2017

...THE FLASH FLOOD WARNING FOR CENTRAL SAN BERNARDINO COUNTY WILL
EXPIRE AT 530 PM PDT...

Rain had ended in the Mojave Preserve area, and flooding is no 
longer expected to pose a threat. Please continue to heed any 
remaining road closures.

LAT...LON 3514 11618 3534 11592 3545 11560 3545 11545
      3557 11535 3518 11486 3487 11483 3480 11543
      3473 11618

$$

Morgan

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 9, 5:01 AM PDTAreal Flood AdvisoryVEFInyo3 hr
Sep 9, 9:50 AM PDTFlash Flood WarningVEFSan Bernardino4 hr
Sep 9, 12:16 PM PDTFlash Flood WarningVEFSan Bernardino4 hr
Sep 9, 1:47 PM PDTFlash Flood WarningVEFSan Bernardino4 hr
Sep 9, 2:17 PM PDTFlash Flood WarningVEFInyo4 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.