Alert archive / California / Flash Flood Warnings in 2021

Flash Flood Warning 20, NWS San Diego, CA

October 25, 2021San Bernardino County, California

NWS San Diego, CA issued this flash flood warning at Oct 25, 2021, 4:20 PM PDT for San Bernardino County, California. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Oct 25, 2021, 4:20 PM PDT (23:20 UTC)
Expired: Oct 25, 2021, 7:15 PM PDT
In force: 3 hr
Issued by: NWS San Diego, CA
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County San Bernardino County, CA

The radar

The Santa Ana Mts radar (KSOX), 70 km from the middle of the area, began a volume at 23:19 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, 11.3 hours before the alert went out and 147 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 666 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 54 m²/s²
0-3 km storm-relative helicity: 90 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

458 
WGUS56 KSGX 252320
FFWSGX
CAC071-260215-
/O.NEW.KSGX.FF.W.0020.211025T2320Z-211026T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Diego CA
420 PM PDT Mon Oct 25 2021

The National Weather Service in San Diego has issued a

* Flash Flood Warning for...
  The El Dorado Fire burn scar in...
  San Bernardino County in southern California...

* Until 715 PM PDT.

* At 420 PM PDT, Doppler radar indicated heavy rain over the El 
  Dorado Fire Burn Scar. Between 0.5 and 1 inch of rain has fallen. 
  The expected rainfall rate is 0.75 to 1 inch in 1 hour. Additional 
  rainfall amounts of 0.5 to 1.25 inches are possible in the warned 
  area. Flash flooding is ongoing or expected to begin shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through the in and below the upper portions of the El Dorado 
Fire Burn Scar. The debris flow can consist of rock, mud, vegetation 
and other loose materials.

  HAZARD...Life threatening flash flooding. Heavy rain producing
           flash flooding in and around the El Dorado Fire Burn
           Scar.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of areas in and around
           the El Dorado Fire Burn Scar.

* Some locations that will experience flash flooding include...
  Forest Falls, Angelus Oaks, Hwy 38 Between Yucaipa And Onyx 
  Summit, Seven Oaks, Mountain Home Village and Barton Flats 
  Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life threatening situation. Heavy rainfall may cause 
extensive and severe flash flooding of creeks, streams, and ditches 
in the El Dorado Burn Scar. Severe debris flows can also be 
anticipated across roads. Roads and driveways may be washed away in 
places. If you encounter flood waters, climb to safety.

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

&&

LAT...LON 3408 11700 3409 11704 3419 11700 3418 11685
      3408 11689 3407 11694

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...0.75-1 INCH IN 1 HOUR

$$

SS

2 follow-up statements

344 
WGUS76 KSGX 260040
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
540 PM PDT Mon Oct 25 2021

CAC071-260215-
/O.CON.KSGX.FF.W.0020.000000T0000Z-211026T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
540 PM PDT Mon Oct 25 2021

...FLASH FLOOD WARNING FOR THE EL DORADO FIRE BURN SCAR REMAINS IN 
EFFECT UNTIL 715 PM PDT THIS EVENING FOR SAN BERNARDINO COUNTY...

At 540 PM PDT, Doppler radar indicated heavy rain over the El Dorado 
Fire Burn Scar. Between 0.5 and 1 inch of rain has fallen. The 
expected rainfall rate is 0.25 to 0.5 inches in 1 hour. Additional 
rainfall amounts of 0.25 to 0.5 inches are possible in the warned 
area. Flash flooding is ongoing or expected to begin shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through the in and below the upper portions of the El Dorado 
Fire Burn Scar. The debris flow can consist of rock, mud, vegetation 
and other loose materials.

HAZARD...Life threatening flash flooding. Heavy rain producing
         flash flooding in and around the El Dorado Fire Burn
         Scar.

SOURCE...Radar.

IMPACT...Life threatening flash flooding of areas in and around
         the El Dorado Fire Burn Scar.

Some locations that will experience flash flooding include...
  Forest Falls, Angelus Oaks, Hwy 38 Between Yucaipa And Onyx 
  Summit, Seven Oaks, Mountain Home Village and Barton Flats 
  Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life threatening situation. Heavy rainfall may cause 
extensive and severe flash flooding of creeks, streams, and ditches 
in the El Dorado Burn Scar. Severe debris flows can also be 
anticipated across roads. Roads and driveways may be washed away in 
places. If you encounter flood waters, climb to safety.

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

&&

LAT...LON 3408 11700 3409 11704 3419 11700 3418 11685
      3408 11689 3407 11694

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...0.25-0.5 INCHES IN 1 HOUR

$$

SS

327 
WGUS76 KSGX 260206
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
706 PM PDT Mon Oct 25 2021

CAC071-260216-
/O.EXP.KSGX.FF.W.0020.000000T0000Z-211026T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
706 PM PDT Mon Oct 25 2021

...FLASH FLOOD WARNING FOR THE EL DORADO FIRE BURN SCAR WILL EXPIRE 
AT 715 PM PDT THIS EVENING FOR SAN BERNARDINO COUNTY...

Heavy rain has ended over the El Dorado Fire. However, light rain 
may produce additional runoff and flooding. A Flood Advisory remains 
in effect for this area through 815 PM.

LAT...LON 3408 11700 3409 11704 3419 11700 3418 11685
      3408 11689 3407 11694

$$

SS

The office that day

Everything else NWS San Diego, CA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 25, 4:13 PM PDT	Areal Flood Advisory	SGX	Riverside, San Bernardino	4 hr

Nearby

Flash Flood Warnings in California, 2021 Every flash flood warning 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.