Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 48, NWS Las Vegas, NV

July 25, 2017San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 25, 2017, 4:07 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
Jul 25, 2017, 4:07 PM PDT (23:07 UTC)
Expired
Jul 25, 2017, 7:00 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 Las Vegas radar (KESX), 109 km from the middle of the area, began a volume at 23:06 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 25, 5:27 PM PDTFLASH FLOOD11 Nnw Baker, CACALIFORNIA HIGHWAY PATROL REPORTED ROADWAY FLOODING ON SR-127 AT MILE MARKER 12.

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, 11.1 hours before the alert went out and 148 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 2017-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 916 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 2017-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 149 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
916 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
897 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
149 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.5
Supercell composite
3.2

Open this sounding in Storm Lab

The text

As transmitted.

753 
WGUS55 KVEF 252307
FFWVEF
CAC071-260200-
/O.NEW.KVEF.FF.W.0048.170725T2307Z-170726T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
407 PM PDT TUE JUL 25 2017

The National Weather Service in Las Vegas has issued a

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

* Until 700 PM PDT

* At 405 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain over Kelso, Highway 127 north of Baker, and just 
  southwest of Amboy. These storms were moving slowly northeast. 
  Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Kelso, Baker, Ludlow and Amboy. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3527 11555 3436 11558 3435 11623 3563 11626
      3547 11561

$$

Morgan
3 follow-up statements
268 
WGUS75 KVEF 260002
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
502 PM PDT TUE JUL 25 2017

CAC071-260200-
/O.CON.KVEF.FF.W.0048.000000T0000Z-170726T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
502 PM PDT TUE JUL 25 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 700 PM PDT FOR
NORTH CENTRAL SAN BERNARDINO COUNTY...

At 500 PM PDT, Doppler radar indicated that heavy rain which had 
been approaching Amboy had dissipated, so that area is no longer 
under the flash flood warning. Rain had also ended in Kelso, but 
radar indicated that very heavy rain fell there, so the warning 
remains in effect for the possibility of flooded roads. Rain was 
also still falling on Highway 127 north of Baker, so the warning 
remains in effect there as well.

Some locations that will experience flooding include...
Kelso and Baker. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3527 11555 3497 11556 3493 11624 3563 11626
      3547 11561

$$

Morgan
263 
WGUS75 KVEF 260057
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
557 PM PDT TUE JUL 25 2017

CAC071-260200-
/O.CON.KVEF.FF.W.0048.000000T0000Z-170726T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
557 PM PDT TUE JUL 25 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 700 PM PDT FOR
NORTH CENTRAL SAN BERNARDINO COUNTY...

At 527 PM PDT, the California Highway Patrol reported that Highway 
127 was flooded 12 miles north of Baker. At 555 PM PDT, Doppler 
radar indicated that most rain had ended in the area, however, the 
flash flood warning will continue due to the ongoing flooding. 

Some locations that will experience flooding include...
Kelso and Baker. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3527 11555 3497 11556 3493 11624 3563 11626
      3547 11561

$$

Morgan
071 
WGUS75 KVEF 260154
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
654 PM PDT TUE JUL 25 2017

CAC071-260204-
/O.EXP.KVEF.FF.W.0048.000000T0000Z-170726T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
654 PM PDT TUE JUL 25 2017

...THE FLASH FLOOD WARNING FOR NORTH CENTRAL SAN BERNARDINO COUNTY
WILL EXPIRE AT 700 PM PDT...

Heavy rain had ended on Highway 127, and no new flooding is 
expected. Please continue to heed any remaining road closures.

LAT...LON 3527 11555 3497 11556 3493 11624 3563 11626
      3547 11561

$$

Morgan

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 6:30 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 24, 6:54 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 24, 7:40 PM PDTFlash Flood WarningVEFSan Bernardino2 hr
Jul 24, 11:59 PM PDTFlash Flood WatchVEFSan Bernardino20 hr
Jul 25, 11:06 AM PDTFlash Flood WarningVEFSan Bernardino6 hr
Jul 25, 11:39 AM PDTFlash Flood WarningVEFInyo3 hr
Jul 25, 1:28 PM PDTFlash Flood WarningVEFSan Bernardino3 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.