Alert archive / California / Flash Flood Warnings in 1989

Flash Flood Warning 1, NWS San Diego, CA

July 27, 1989Imperial County, California

NWS San Diego, CA issued this flash flood warning at Jul 27, 1989, 6:00 PM PDT for Imperial County, California. It was in force for 2 hr.

The area

The counties it named.

The facts

Issued
Jul 27, 1989, 6:00 PM PDT (01:00 UTC)
Expired
Jul 27, 1989, 8:00 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, 1.0 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 1989-07-28Temperature 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 1989-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 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
3647 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
3 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 280107
FFWLAX
CAC025-065-280300-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM AND FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LOS ANGELES CA
6 PM PDT PDT THU JUL 27 1989

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM AND
FLASH FLOOD WARNING EFFECTIVE UNTIL 8 PM PDT FOR PEOPLE IN THE
FOLLOWING COUNTIES OF:

EXTREME EASTERN IMPERIAL
EXTREME EASTERN RIVERSIDE

AT 6PM SATELLITE INDICATED TWO THUNDERSTORMS MERGING OVER SOUTHWEST
AIRZONA. THIS WILL LIKELY PRODUCE ANOTHER STRONG THUNDERSTORM ALONG
THE COLORADO RIVER VALLEY BETWEEN BLYTHE AND WINTERHAVEN WITHIN THE
NEXT TWO HOURS.

DAMAGING WINDS OF OVER 60 MPH CAN BE EXPECTED IN THE WARNING AREA. IN
ADDITION...HEAVY RAIN IS LIKELY...AND THERE IS A STRONG POSSIBILITY THAT
FLASH FLOODING WILL OCCUR.

PEOPLE ARE ADVISED TO TAKE NECESSARY PRECAUTIONS IMMEDIATELY...AVOID
DRY WASHES...DO NOT ATTEMPT TO CROSS FLOODED ROADWAYS...AND SEEK
SHELTER INDOORS TO AVOID STRONG WINDS AND FREQUENT LIGHTNING.

PETERSON

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 6:00 PM PDTSevere Thunderstorm WarningSGXImperial2 hr

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.