Alert archive / California / Flash Flood Warnings in 1989

Flash Flood Warning 3, NWS San Diego, CA

August 9, 1989Imperial County, California

NWS San Diego, CA issued this flash flood warning at Aug 9, 1989, 7:00 PM PDT for Imperial County, California. It was in force for 2 hr.

The area

The counties it named.

The facts

Issued
Aug 9, 1989, 7:00 PM PDT (02:00 UTC)
Expired
Aug 9, 1989, 9:00 PM PDT
In force
2 hr
Issued by
NWS San Diego, CA
Area
Whole counties

County Imperial County, CA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 2.0 hours before the alert went out and 173 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 1989-08-10Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 00:00Z on 1989-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 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
3643 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
45 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 
TTAA00 KLAX 100202
FFWLAX
CAC025-065-071-100400-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM AND FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LOS ANGELES CA
7 PM PDT WED AUG 9 1989

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM AND
FLASH FLOOD WARNING EFFECTIVE UNTIL 9 PM PDT FOR PEOPLE IN THE
FOLLOWING COUNTIES OF:

EXTREME EASTERN SAN BERNARDINO
EXTREME EASTERN RIVERSIDE
EXTREME EASTERN IMPERIAL

AT 7 PM RADAR AND SATELLITE CONTINUE TO INDICATE A LARGE THUNDERSTORM
COMPLEX MOVING OVER THE EASTERN DESERTS. IT HAS EXTENDED FURTHER
EAST AND NORTH AND NOW COVERS THE EASTERN DESERTS FROM BAKER TO
DESERT CENTER TO WINTERHAVEN.

THIS STORM WILL BRING STRONG WINDS GUSTING TO 60 MPH OR MORE WITH
HEAVY RAIN TO THE WARNING AREA FOR THE NEXT FEW HOURS. THE HEAVY
RAIN WILL LIKELY CAUSE LOCAL FLASH FLOODING.

IF YOU ARE DRIVING IN THE WARNING AREA USE EXTRA CAUTION...AVOID
FLOODED HIGHWAY DIPS...AND BE AWARE THAT THE STRONG WINDS MAY REDUCE
VISIBILITIES TO NEAR ZERO. THE FOLLOWING MAJOR HIGHWAYS IN THE EASTERN
DESERT AREAS MAY BE AFFECTED...INTERSTATE 40...INTERSTATE 10...
INTERSTATE 8...INTERSTATE 15 AND HIGHWAYS 78 AND 95.

IF YOU ARE OUTSIDE AND THREATENING WEATHER APPROASCHES GO TO A SAFE PLACE
IMMEDIATELY.

PETERSON

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Aug 9, 1:41 PM PDT, 5 hours 19 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
1:40 PM PDT WED AUG 09 1989

...DEVELOPING THUNDERSTORMS HAVE PROMPTED A FLASH FLOOD WATCH FOR
SAN DIEGO MOUNTAINS AND DESERTS TIL 9 PM PDT...

THUNDERSTORMS IN A MOIST SOUTHERLY FLOW ARE RAPIDLY DEVELOPING AND
HAVE PROMPTED A FLASH FLOOD WATCH FORTHE MOUNTAINS AND DESERTS OF
SAN DIEGO COUNTY UNTIL 9 TONIGHT.

SATELLITE PICTURES AND RADAR INDICATES THUNDERSTORMS ERUPTING
RAPIDLY IN THE MOUNTAINS AND DESERTS OF SAN DIEGO COUNTY WITH
STORMS HEADING NORTH.  HEAVIEST RAINS SO FAR HAVE BEEN REPORTED
FROM THE SANTA YSABEL ALERT RAIN GAGE WHERE 0.67 INCH FELL IN A
HALF HOUR.  SO FAR .08 INCH AT CUYAMACA.

A FLASH FLOOD WATCH MEANS THAT FLASH FLOODING OF WASHES...SMALL
STREAMS...RIVERS AND OTHER DRAINAGE AREAS IS POSSIBLE IN THE
WATCH AREA.  IF YOU ARE IN THE WATCH AREA KEEP AN EYE ON THE
CHANGING WEATHER AND BE READY FOR IMMEDIATE ACTION IF HEAVY RAINS
BEGIN OR A WARNING IS ISSSUED.

SHIGEHARA

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 7:00 PM PDTSevere Thunderstorm WarningSGXImperial2 hr
Aug 10, 3:33 PM PDTFlash Flood WarningSGXSan Diego57 min

Nearby

Flash Flood Warnings in California, 1989Every flash flood warning in 1989

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.