Alert archive / California / Flash Flood Warnings in 1993

Flash Flood Warning 8, NWS San Francisco Bay Area, CA

January 20, 1993Marin County, Sonoma County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 20, 1993, 7:15 AM PST for Marin County, Sonoma County, California. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued
Jan 20, 1993, 7:15 AM PST (15:15 UTC)
Expired
Jan 20, 1993, 12:00 PM PST
In force
5 hr
Issued by
NWS San Francisco Bay Area, CA
Area
Whole counties

Counties Marin County, CA, Sonoma County, CA

The nearest sounding before it

Oakland, CA (KOAK), launched 12:00Z, 3.3 hours before the alert went out and 84 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, Oakland, CA at 12:00Z on 1993-01-20Temperature 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, Oakland, CA at 12:00Z on 1993-01-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 342 square meters per square second.1939587897Sfc1 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
532 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
342 m²/s²
0-3 km storm-relative helicity
472 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 KSFO 201528
FFWSFO
CAC041-097-202000-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
715 AM PST WED JAN 20 1993
 
THE NATIONAL WEATHER SERVICE IN SAN FRANCISCO HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  12 NOON PST
FOR PEOPLE AND PROPERTY IN THE FOLLOWING LOCATIONS...
 
IN CENTRAL CALIFORNIA
 
   ..SONOMA AND MARIN COUNTIES...
 
FLASH FLOODING WAS REPORTED BY SONOMA COUNTY OFFICIALS IN STREAMS
AND TRIBUTARIES OF THE RUSSIAN RIVER...ESPECIALLY IN THE COMMUNITIES
OF SANTA ROSA / HEALDSBURG / SEBASTAPOL / FORESTVILLE.  ALSO..LOCAL
STREAMS IN BOTH COUNTIES THAT REACH TO THE SAN PABLO AND 
SAN FRANCISCO BAYS MAY HAVE RESTRICTED FLOW SINCE FLOW INTO THE BAY
WILL COINCIDE WITH HIGH ASTRONOMICAL TIDES LATER THIS MORNING. 
 
A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.  MOST FLASH FLOOD DEATHS 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. TO ESCAPE RISING WATER...MOVE UP TO HIGHER GROUND
IMMEDIATELY.

IN HIGHER AND STEEP TERRAIN...HEAVY RAIN WILL CAUSE ROCK/MUD/DEBRIS
SLIDES. BE AWARE OF YOUR SURROUNDINGS IN THIS POTENTIALLY DANGEROUS
WEATHER SITUATION.

GSL

The office that day

Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 20, 10:55 AM PSTFlash Flood WarningMTRMarin, Sonoma4 hr
Jan 20, 3:40 PM PSTFlash Flood WarningMTRNapa, Sonoma6 hr
Jan 20, 3:40 PM PSTFlash Flood WarningMTRMarin6 hr

Nearby

Flash Flood Warnings in California, 1993Every flash flood warning in 1993

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.