Alert archive / California / Flash Flood Warnings in 2004

Flash Flood Warning 77, NWS San Diego, CA

October 20, 20044 counties in California

NWS San Diego, CA issued this flash flood warning at Oct 20, 2004, 6:15 AM PDT for 4 counties in California. It was in force for 3 hr. 10 reports 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: Oct 20, 2004, 6:15 AM PDT (13:15 UTC)
Expired: Oct 20, 2004, 9:00 AM PDT
In force: 3 hr
Issued by: NWS San Diego, CA
Area: Counties, with a storm outline in the text

Counties Orange County, CA, Riverside County, CA, San Bernardino County, CA, San Diego County, CA

The radar

The Santa Ana Mts radar (KSOX), 50 km from the middle of the area, began a volume at 13:17 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

Time	Report	Where	Remark
Oct 20, 6:16 AM PDT	FLASH FLOOD	Riverside, CA	LANES FLOODED ON WESTBOUND HWY 91 AT MISSION INN AV.
Oct 20, 6:30 AM PDT	FLASH FLOOD	Santa Ana, CA	NUMEROUS FREEWAY RAMPS CLOSED BECAUSE OF FLOODING. I-5 TO HWY 22 AT 518 AM. HWY 22 CLOSED ALL AROUND I-5 AND HWY 57. HWY 91 OFFRAMP AT TUSTIN CLOSED AT 535 AM. FAIRVIEW ONRAMP AT HWY 73 CLOSED AT 630 AM.
Oct 20, 6:31 AM PDT	FLASH FLOOD	Fontana, CA	ETIWANDA-FONTANA FLOODING. EASTBOUND I-10 CLOSED. VEHICLES FLOATING AWAY.
Oct 20, 6:51 AM PDT	FLOOD	San Bernardino, CA	ETIWANDA AV. FLOODED FROM SAN BERNARDINO TO I-10.
Oct 20, 7:07 AM PDT	FLASH FLOOD	Laguna Hills, CA	SIX INCHES OF WATER IN LANES OF NORTHBOUND I-5 AT ALICIA PKWY.
Oct 20, 7:14 AM PDT	FLASH FLOOD	Laguna Hills, CA	SEVERAL FEET OF WATER IN SLOW LANE OF NORTHBOUND HWY 73 AT ALISO CREEK RD.
Oct 20, 7:52 AM PDT	FLASH FLOOD	Placentia, CA	LOCAL FLOODING. 2.90 INCHES OF RAIN SINCE MIDNIGHT.
Oct 20, 8:39 AM PDT	FLASH FLOOD	Lake Elsinore, CA	MUDSLIDE ON WESTSIDE OF LAKE ELSINORE AT HWY 74 AND GRAND AV.
Oct 20, 8:42 AM PDT	FLASH FLOOD	Orange, CA	FLOODING AT THE CONNECTION OF THE HWY 55 AND HWY 91.
Oct 20, 8:52 AM PDT	FLASH FLOOD	San Bernardino, CA	FLOODED ROADWAYS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Edwards AFB, CA (KEDW), launched 12:00Z, 1.3 hours before the alert went out and 112 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: 533 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: -10 m²/s²
0-3 km storm-relative helicity: -64 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS56 KSGX 201326
FFWSGX
CAC059-065-071-073-201600-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
615 AM PDT WED OCT 20 2004

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WESTERN RIVERSIDE COUNTY IN SOUTHEAST CALIFORNIA
  THIS INCLUDES THE CITIES OF...TEMECULA...RUBIDOUX...RIVERSIDE...
  PERRIS...PALM SPRINGS...PALM DESERT...NORCO...MORENO VALLEY...LAKE
  ELSINORE...INDIO...HEMET...CORONA...CATHEDRAL CITY...BANNING
  
  SOUTHWESTERN SAN BERNARDINO COUNTY IN SOUTHEAST CALIFORNIA
  THIS INCLUDES THE CITIES OF...FOREST FALLS...YUCAIPA...
  VICTORVILLE...UPLAND...SAN BERNARDINO...RIALTO...REDLANDS...RANCHO
  CUCAMONGA...ONTARIO...MONTCLAIR...HIGHLAND...HESPERIA...FONTANA...
  COLTON...CHINO HILLS...CHINO...APPLE VALLEY
  
  ORANGE COUNTY IN SOUTHWEST CALIFORNIA
  THIS INCLUDES THE CITIES OF...YORBA LINDA...WESTMINSTER...TUSTIN
  FOOTHILLS...TUSTIN...STANTON...SEAL BEACH...SANTA ANA...SAN JUAN
  CAPISTRANO...PLACENTIA...ORANGE...MISSION VIEJO...LAGUNA HILLS...
  IRVINE...GARDEN GROVE...FULLERTON...FOUNTAIN VALLEY...EL TORO...
  COSTA MESA...BREA...ANAHEIM

* UNTIL 900 AM PDT

* AT 600 AM PDT...THE PUBLIC REPORTED MULTIPLE AREAS OF FLASH 
FLOODING FROM A STRONG COLD FRONT MOVING THROUGH THE AREA. REPORTS 
OF 1 TO 3 INCHES OF RAIN HAVE BEEN REPORTED. THE HEAVIEST RAIN HAS 
BEEN NEAR DEVORE...LYTLE CREEK AND CYPRESS. THE FRONT WAS MOVING   
SOUTHEAST AT 15 MPH.

MUD SLIDES AND ROCK SLIDES ARE EXPECTED WITH THIS STORM. MUD SLIDES 
AND ROCK SLIDES CAN POTENTIALLY TRAP AND KILL PEOPLE CAUGHT IN THEIR 
PATH.
 
DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE 
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS 
SAFELY. MOVE TO HIGHER GROUND.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. 
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY. 
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE 
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS 
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY 
AUTOMOBILE.

LAT...LON 3377 11810 3346 11759 3345 11610 3391 11616
      3401 11645 3445 11642 3464 11684 3463 11765
      3432 11767 3405 11772

$$

WHITLOW

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 19, 11:50 PM PDT	Flash Flood Warning	SGX	San Bernardino	6 hr
Oct 20, 4:00 AM PDT	Flash Flood Warning	SGX	Orange	3 hr
Oct 20, 9:00 AM PDT	Flash Flood Warning	SGX	Orange, Riverside, San Bernardino, San Diego	2 hr
Oct 20, 10:38 AM PDT	Flash Flood Warning	SGX	Riverside, San Bernardino, San Diego	2 hr
Oct 20, 1:00 PM PDT	Flash Flood Warning	SGX	San Diego	2 hr
Oct 20, 3:00 PM PDT	Flash Flood Warning	SGX	San Diego	4 hr

Nearby

Flash Flood Warnings in California, 2004 Every flash flood warning in 2004

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.