Alert archive / California / Flash Flood Warnings in 1990

Flash Flood Warning 21, NWS Los Angeles, CA

September 22, 1990San Luis Obispo County, California

NWS Los Angeles, CA issued this flash flood warning at Sep 22, 1990, 4:31 PM PDT for San Luis Obispo County, California. It was in force for 59 min.

The area

The counties it named.

The facts

Issued
Sep 22, 1990, 4:31 PM PDT (23:31 UTC)
Expired
Sep 22, 1990, 5:30 PM PDT
In force
59 min
Issued by
NWS Los Angeles, CA
Area
Whole counties

County San Luis Obispo 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

Vandenberg AFB, CA (KVBG), launched 12:00Z, 11.5 hours before the alert went out and 73 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, Vandenberg AFB, CA at 12:00Z on 1990-09-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 271 joules per kilogram.LCLLFCEL10008507005003002001001 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, Vandenberg AFB, CA at 12:00Z on 1990-09-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 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
271 J/kg
Mixed-layer CIN
-126 J/kg
Mixed-layer LCL
1136 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSMX 222331 RRA
FFWSMX
CAC079-230030-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SANTA MARIA CA
431 PM PDT SAT SEP 22 1990
 
THE NATIONAL WEATHER SERVICE IN SANTA MARIA HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 530 PM PDT FOR THE
FOLLOWING...
 
IN WEST CENTRAL CALIFORNIA
 
   ...EASTERN SAN LUIS OBISPO COUNTY
 
AT 430 PM PDT...THE CALIFORNIA HIGHWAY PATROL IN SAN LUIS OBISPO
COUNTY REPORTED FLOODING ALONG HIGHWAY 58 IN THE TOWN OF CALIFORNIA
VALLEY. WATER WAS FLOWING OVER THE ROAD TO A DEPTH OF 3 FEET.
 
MOST DEATHS IN FLASH FLOODING OCCUR IN AUTOMOBILES.  DO NOT
ATTEMPT TO CROSS BRIDGES...DIPS...OR LOW SPOTS IF WATER COVERS
THE ROADWAY.  NEVER TRY TO CROSS A FLOWING STREAM...EVEN A
SMALL ONE...ON FOOT.
 
NNNN

The office that day

Everything else NWS Los Angeles, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 22, 4:17 PM PDTFlash Flood WarningLOXSanta Barbara58 min

Nearby

Flash Flood Warnings in California, 1990Every flash flood warning in 1990

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.