Alert archive / California / Areal Flood Advisories in 2021

Areal Flood Advisory 21, NWS Las Vegas, NV

July 28, 2021San Bernardino County, California

NWS Las Vegas, NV issued this areal flood advisory at Jul 28, 2021, 12:59 PM PDT for San Bernardino County, California. It was in force for 22 min.

The area

The outline as issued.

The facts

Issued
Jul 28, 2021, 12:59 PM PDT (19:59 UTC)
Expired
Jul 28, 2021, 1:21 PM PDT
In force
22 min
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon

County San Bernardino County, CA

The radar

The Santa Ana Mts radar (KSOX), 133 km from the middle of the area, began a volume at 20:00 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

San Diego, CA (KNKX), launched 12:00Z, 8.0 hours before the alert went out and 176 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, San Diego, CA at 12:00Z on 2021-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, San Diego, CA at 12:00Z on 2021-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1533 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
55 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

542 
WGUS85 KVEF 281959
FLSVEF

Flood Advisory
National Weather Service Las Vegas NV
1259 PM PDT Wed Jul 28 2021

CAC071-282300-
/O.NEW.KVEF.FA.Y.0021.210728T1959Z-210728T2300Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
1259 PM PDT Wed Jul 28 2021

The National Weather Service in Las Vegas has issued a

* Flood Advisory for...
  San Bernardino County in southern California...

* Until 400 PM PDT.

* At 1259 PM PDT, Doppler radar indicated heavy rain due to 
  thunderstorms south of Joshua Tree. Minor flooding is likely to 
  begin shortly...Especially along Park Blvd and Indian Cove Roads 
  south of Highway 62. Additional flooding may impact Highway 62 
  between Twentynine Palms and Yucca Valley. Between 0.5 and 1 inch 
  of rain has fallen south of Joshua Tree.

* Some locations that will experience flooding include...
  Joshua Tree Lake Campground and Joshua Tree.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3408 11632 3414 11636 3419 11637 3422 11635
      3425 11630 3426 11627 3426 11620 3424 11615
      3419 11609 3412 11606 3412 11626 3408 11626

$$

CO
1 follow-up statement
978 
WGUS85 KVEF 282021
FLSVEF

Flood Advisory
National Weather Service Las Vegas NV
121 PM PDT Wed Jul 28 2021

CAC071-282031-
/O.CAN.KVEF.FA.Y.0021.000000T0000Z-210728T2300Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
121 PM PDT Wed Jul 28 2021

...FLOOD ADVISORY FOR SAN BERNARDINO COUNTY HAS BEEN REPLACED WITH A 
FLASH FLOOD WARNING...

LAT...LON 3408 11632 3414 11636 3419 11637 3422 11635
      3425 11630 3426 11627 3426 11620 3424 11615
      3419 11609 3412 11606 3412 11626 3408 11626

$$

CO

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 5:56 PM PDTAreal Flood AdvisoryVEFSan Bernardino2 hr
Jul 28, 1:21 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino3 hr

Nearby

Areal Flood Advisories in California, 2021Every areal flood advisory in 2021

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.