Alert archive / California / Flash Flood Warnings in 1993

Flash Flood Warning 9, 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, 10:55 AM PST for Marin County, Sonoma County, California. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued: Jan 20, 1993, 10:55 AM PST (18:55 UTC)
Expired: Jan 20, 1993, 3:00 PM PST
In force: 4 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, 6.9 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-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: 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 201855
FFWSFO
CAC041-097-202300-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1055 AM PST WED JAN 20 1993
 
THE NATIONAL WEATHER SERVICE IN SAN FRANCISCO HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 3 PM PST
FOR PEOPLE AND PROPERTY IN THE FOLLOWING LOCATIONS...
 
IN NORTH CENTRAL CALIFORNIA 
 
...SONOMA AND MARIN COUNTIES...
 
AT 1040 AM..SATELLITE IMAGERY..AND SURFACE STATION REPORTS..
INDICATE LOCALLY HEAVY RAIN STILL FALLING OVER THE THE NORTHERN SAN
FRANCISCO BAY AREA WITH LIGHTER RAIN ELSEWHERE. THE HEAVIEST RAIN IS
STILL BEING REPORTED IN NORTHERN SONOMA COUNTY NEAR HEALDBURG AND IN
MARIN COUNTY NEAR ROSS.

STREAMS AND CREEKS OF SONOMA AND MARIN COUNTIES ARE CONTINUING TO
RISE...AND STREAM OVERFLOWS HAVE BEEN REPORTED IN THE HEALDSBERG/
SANTA ROSA/ FORESTVILLE AND SEBASTOPOL AREAS. CORTE MADERA CREEK NEAR
KENTFIELD AND ROSS IN MARIN COUNTY IS ONLY 1/2 FOOT BELOW FLOOD STAGE
AND IS CONTINUING TO RISE. ALL STREAMS WILL CONTINUE TO RISE FOR THE
NEXT SEVERAL HOURS AND ANY RAIN THAT DOES FALL WILL RUNOFF INTO THE
WATERWAYS...ROADS AND LOW LYING AREAS.

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. MINOR MUDSLIDE AND DEBRIS HAVE BEEN REPORTED. PLEASE BE
AWARE OF THIS POTENTIALLY DANGEROUS SITUATION.
 
LISTEN TO NATIONAL WEATHER SERVICE RADIO ON FREQUENCIES 162.55
OR 162.40 MHZ...OR YOUR LOCAL TELEVISION OR RADIO STATION FOR 
FURTHER INFORMATION.

DLR

The office that day

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

Issued	Product	Office	Counties	Lasted
Jan 20, 7:15 AM PST	Flash Flood Warning	MTR	Marin, Sonoma	5 hr
Jan 20, 3:40 PM PST	Flash Flood Warning	MTR	Napa, Sonoma	6 hr
Jan 20, 3:40 PM PST	Flash Flood Warning	MTR	Marin	6 hr

Nearby

Flash Flood Warnings in California, 1993 Every 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.