Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 22, NWS San Diego, CA

September 8, 2017Riverside County, California

NWS San Diego, CA issued this flash flood warning at Sep 8, 2017, 5:33 PM PDT for Riverside 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
Sep 8, 2017, 5:33 PM PDT (00:33 UTC)
Expired
Sep 8, 2017, 8:30 PM PDT
In force
3 hr
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

County Riverside County, CA

The radar

The San Diego radar (KNKX), 115 km from the middle of the area, began a volume at 00:35 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 00:00Z, 0.6 hours before the alert went out and 134 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 00:00Z on 2017-09-09Temperature 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 00:00Z on 2017-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 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
2107 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
84 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

307 
WGUS56 KSGX 090033
FFWSGX
CAC065-090330-
/O.NEW.KSGX.FF.W.0022.170909T0033Z-170909T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Diego CA
533 PM PDT FRI SEP 8 2017

The National Weather Service in San Diego has issued a

* Flash Flood Warning for...
  Riverside County in southern California...

* Until 830 PM PDT

* At 530 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...
  Indio, Coachella, Palm Desert, Rancho Mirage, Thermal, Hwy 74
  Between Anza And Palm Desert, La Quinta, Mecca, Indian Wells, Santa
  Rosa Mountain and Bermuda Dunes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3351 11597 3352 11605 3351 11605 3350 11608
      3345 11604 3343 11604 3342 11607 3343 11639
      3377 11645 3381 11609 3375 11601 3374 11595
      3352 11595

$$

Small
3 follow-up statements
481 
WGUS76 KSGX 090112
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
612 PM PDT FRI SEP 8 2017

CAC065-090330-
/O.CON.KSGX.FF.W.0022.000000T0000Z-170909T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-
612 PM PDT FRI SEP 8 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM PDT FOR
RIVERSIDE COUNTY...

At 607 PM PDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area.  Flash flooding is likely.

Some locations that will likely experience flooding include...
Indio, Coachella, Palm Desert, Rancho Mirage, Thermal, Hwy 74 Between
Anza And Palm Desert, La Quinta, Mecca, Indian Wells, Santa Rosa
Mountain and Bermuda Dunes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now. Act quickly to protect your life. Please 
heed any road closures and avoid areas of flowing/ponding water on 
roadways.

&&

LAT...LON 3351 11597 3352 11605 3351 11605 3350 11608
      3345 11604 3343 11604 3342 11607 3343 11639
      3377 11645 3381 11609 3375 11601 3374 11595
      3352 11595

$$

Small
218 
WGUS76 KSGX 090223
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
723 PM PDT FRI SEP 8 2017

CAC065-090330-
/O.CON.KSGX.FF.W.0022.000000T0000Z-170909T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-
723 PM PDT FRI SEP 8 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM PDT FOR
RIVERSIDE COUNTY...

At 706 PM PDT, Doppler radar indicated weakening thunderstorms 
in the warned area. Flooding is still possible as the runoff 
continues.  

Some locations that will likely experience flooding include...
Indio, Coachella, Palm Desert, Rancho Mirage, Thermal, Hwy 74 Between
Anza And Palm Desert, La Quinta, Mecca, Indian Wells, Santa Rosa
Mountain and Bermuda Dunes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Residents as well as motorists driving through the area should heed 
any road closures and avoid areas of flowing/ponding water on 
roadways.

&&

LAT...LON 3351 11597 3352 11605 3351 11605 3350 11608
      3345 11604 3343 11604 3342 11607 3343 11639
      3377 11645 3381 11609 3375 11601 3374 11595
      3352 11595

$$

Small
896 
WGUS76 KSGX 090323
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
823 PM PDT FRI SEP 8 2017

CAC065-090332-
/O.EXP.KSGX.FF.W.0022.000000T0000Z-170909T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-
823 PM PDT FRI SEP 8 2017

...THE FLASH FLOOD WARNING FOR RIVERSIDE COUNTY WILL EXPIRE AT 830 PM
PDT...

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

LAT...LON 3351 11597 3352 11605 3351 11605 3350 11608
      3345 11604 3343 11604 3342 11607 3343 11639
      3377 11645 3381 11609 3375 11601 3374 11595
      3352 11595

$$

JJT

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 8, 5:49 PM PDTSevere Thunderstorm WarningSGXRiverside56 min
Sep 9, 1:36 PM PDTAreal Flood AdvisorySGXSan Diego3 hr
Sep 9, 2:26 PM PDTSevere Thunderstorm WarningSGXSan Diego64 min
Sep 9, 3:49 PM PDTFlash Flood WarningSGXRiverside3 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.