Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 21, NWS San Diego, CA

September 7, 2017San Diego County, California

NWS San Diego, CA issued this flash flood warning at Sep 7, 2017, 5:01 PM PDT for San Diego 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 7, 2017, 5:01 PM PDT (00:01 UTC)
Expired
Sep 7, 2017, 8:00 PM PDT
In force
3 hr
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

County San Diego County, CA

The radar

The San Diego radar (KNKX), 80 km from the middle of the area, began a volume at 00:04 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, 0.0 hours before the alert went out and 100 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 2017-09-08Temperature 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 2017-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2418 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
34 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.

266 
WGUS56 KSGX 080001
FFWSGX
CAC073-080300-
/O.NEW.KSGX.FF.W.0021.170908T0001Z-170908T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Diego CA
501 PM PDT THU SEP 7 2017

The National Weather Service in San Diego has issued a

* Flash Flood Warning for...
  Northeastern San Diego County in southwestern California...

* Until 800 PM PDT

* At 456 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain 5 to 10 miles northwest of Borrego Springs. Flash 
  flooding will likely begin shortly, including in canyons just west 
  and northwest of Borrego Springs. Flash flooding will be possible 
  in or close to Borrego Springs as water from canyons drains 
  locally into the desert.

* Some locations that will likely experience flooding include...
  Borrego Springs, Hwy 78 Between Borrego Springs Rd And Ocotillo 
  Wells, Hwy S22 Between Ranchita And Borrego Springs, Borrego Palm 
  Canyon, Hwy S22 Between Borrego Springs And Imperial County Line 
  and Los Coyotes Indian Reservation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3342 11616 3316 11620 3320 11657 3342 11658

$$

Maxwell
2 follow-up statements
823 
WGUS76 KSGX 080024
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
524 PM PDT THU SEP 7 2017

CAC073-080300-
/O.CON.KSGX.FF.W.0021.000000T0000Z-170908T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Diego CA-
524 PM PDT THU SEP 7 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 800 PM PDT FOR
NORTHEASTERN SAN DIEGO COUNTY...

At 522 PM PDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area.  The threat of flash flooding is now 
greatest 5 to 10 miles east of Borrego Springs along Highway S-22 
where a severe thunderstorm is occurring. Canyons northwest of 
Borrego Springs could continue to have flooding through about 600 PM.

Some locations that will likely experience flooding include...
Borrego Springs, Hwy 78 Between Borrego Springs Rd And Ocotillo 
Wells, Hwy S22 Between Ranchita And Borrego Springs, Borrego Palm 
Canyon, Hwy S22 Between Borrego Springs And Imperial County Line and 
Los Coyotes Indian Reservation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3342 11616 3316 11620 3320 11657 3342 11658

$$

Maxwell
787 
WGUS76 KSGX 080204
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
704 PM PDT THU SEP 7 2017

CAC073-080213-
/O.CAN.KSGX.FF.W.0021.000000T0000Z-170908T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Diego CA-
704 PM PDT THU SEP 7 2017

...THE FLASH FLOOD WARNING FOR NORTHEASTERN SAN DIEGO COUNTY IS
CANCELLED...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Normally dry washes which filled up with water will recede 
quickly this evening.

LAT...LON 3342 11616 3316 11620 3320 11657 3342 11658

$$

Maxwell

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 7, 5:22 PM PDTSevere Thunderstorm WarningSGXSan Diego53 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.