Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 10, NWS San Diego, CA

August 1, 2017Orange County, Riverside County, California

NWS San Diego, CA issued this flash flood warning at Aug 1, 2017, 3:42 PM PDT for Orange County, Riverside 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 1, 2017, 3:42 PM PDT (22:42 UTC)
Expired
Aug 1, 2017, 6:45 PM PDT
In force
3 hr
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

Counties Orange County, CA, Riverside County, CA

The radar

The Santa Ana Mts radar (KSOX), 37 km from the middle of the area, began a volume at 22:43 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
Aug 1, 4:03 PM PDTFLASH FLOOD4 Nw Lakeland Village, CAMUD AND DEBRIS FLOW FROM A RECANT FIRE FLOWING OVER GRAND AVE. AND PLUMAS ST., BOTH ROADS CLOSED.

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, 10.7 hours before the alert went out and 114 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 2017-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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, San Diego, CA at 12:00Z on 2017-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1271 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
49 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

866 
WGUS56 KSGX 012242
FFWSGX
CAC059-065-020145-
/O.NEW.KSGX.FF.W.0010.170801T2242Z-170802T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Diego CA
342 PM PDT TUE AUG 1 2017

The National Weather Service in San Diego has issued a

* Flash Flood Warning for...
  Riverside County in southern California...
  East central Orange County in southwestern California...

* Until 645 PM PDT

* At 341 PM PDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding will likely begin
  shortly.

* Some locations that will likely experience flooding include...
  Riverside, Moreno Valley, Lake Elsinore, Perris, San Jacinto, March
  Airforce Base, Menifee, Sun City, Woodcrest, Temescal Valley, Lake
  Mathews and Ortega Highway.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now. Act quickly to protect your life.

&&

LAT...LON 3395 11704 3383 11697 3367 11716 3363 11741
      3373 11758 3389 11744 3397 11726

$$

Albright
2 follow-up statements
536 
WGUS76 KSGX 020000
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
500 PM PDT TUE AUG 1 2017

CAC059-065-020145-
/O.CON.KSGX.FF.W.0010.000000T0000Z-170802T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-Orange CA-
500 PM PDT TUE AUG 1 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM PDT FOR
RIVERSIDE AND EAST CENTRAL ORANGE COUNTIES...

At 500 PM PDT, Thunderstorms have weakened across the warned area, 
but runoff from earlier heavy rainfall is expected to continue. 
Therefore the flash flood warning remains in place through 645 PM.

Some locations that will likely experience flooding include...
Riverside, Moreno Valley, Lake Elsinore, Perris, San Jacinto, March
Airforce Base, Menifee, Sun City, Woodcrest, Temescal Valley, Lake
Mathews and Ortega Highway.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now. Act quickly to protect your life.

&&

LAT...LON 3395 11704 3383 11697 3367 11716 3363 11741
      3373 11758 3389 11744 3397 11726

$$

Albright
669 
WGUS76 KSGX 020138
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
638 PM PDT TUE AUG 1 2017

CAC059-065-020148-
/O.EXP.KSGX.FF.W.0010.000000T0000Z-170802T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-Orange CA-
638 PM PDT TUE AUG 1 2017

...THE FLASH FLOOD WARNING FOR RIVERSIDE AND EAST CENTRAL ORANGE
COUNTIES WILL EXPIRE AT 645 PM PDT...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 3395 11704 3383 11697 3367 11716 3363 11741
      3373 11758 3389 11744 3397 11726

$$

Albright

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 12:56 PM PDTFlash Flood WatchSGXOrange, Riverside, San Bernardino, San Diego54 hr
Aug 1, 1:18 PM PDTAreal Flood AdvisorySGXSan Diego3 hr
Aug 1, 1:26 PM PDTSevere Thunderstorm WarningSGXSan Diego64 min
Aug 1, 1:27 PM PDTFlash Flood WarningSGXSan Diego3 hr
Aug 1, 2:52 PM PDTAreal Flood AdvisorySGXOrange, Riverside, San Diego3 hr
Aug 1, 3:01 PM PDTSevere Thunderstorm WarningSGXRiverside59 min
Aug 1, 3:23 PM PDTSevere Thunderstorm WarningSGXOrange, Riverside52 min
Aug 1, 3:57 PM PDTSevere Thunderstorm WarningSGXOrange, Riverside45 min
Aug 1, 4:00 PM PDTSevere Thunderstorm WarningSGXRiverside45 min
Aug 1, 4:17 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino3 hr
Aug 1, 4:36 PM PDTSpecial Weather StatementSGXOrange39 min

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.