Alert archive / California / Flash Flood Warnings in 1992

Flash Flood Warning 4, NWS San Francisco Bay Area, CA

December 10, 1992San Mateo County, Santa Clara County, Santa Cruz County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Dec 10, 1992, 1:48 PM PST for San Mateo County, Santa Clara County, Santa Cruz County, California. It was in force for 117 min.

The area

The counties it named.

The facts

Issued
Dec 10, 1992, 1:48 PM PST (21:48 UTC)
Expired
Dec 10, 1992, 3:45 PM PST
In force
117 min
Issued by
NWS San Francisco Bay Area, CA
Area
Whole counties

Counties San Mateo County, CA, Santa Clara County, CA, Santa Cruz County, CA

The nearest sounding before it

Oakland, CA (KOAK), launched 12:00Z, 9.8 hours before the alert went out and 58 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 1992-12-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 36 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, Oakland, CA at 12:00Z on 1992-12-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 252 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
36 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
534 m above ground
0-6 km bulk shear
70 kt
0-1 km storm-relative helicity
252 m²/s²
0-3 km storm-relative helicity
291 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 102150
FFWSFO
CAC041-081-085-087-102345-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
148 PM PST THU DEC 10 1992
 
THE NATIONAL WEATHER SERVICE IN SAN FRANCISCO HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  400 PM PST
FOR PEOPLE IN THE FOLLOWING LOCATIONSS...
 
IN CENTRAL CALIFORNIA...THE COASTAL MOUNTAINS OF
 
   ...MARIN COUNTY...SAN MATEO COUNTY...SANTA CLARA COUNTY
   ...SANTA CRUZ COUNTY
 
HEAVY RAIN ASSOCIATED WITH A STRONG PACIFIC COLD FRONT IS UPON THE SAN
FRANCISCO BAY AREA. RAINFALL AMOUNTS ARE IN THE MODERATE TO HEAVY RANGE
IN AREAS ALREADY SATURATED OVER THE PAST FEW DAYS...ADDITIONAL AMOUNTS
WILL RUN OFF VERY RAPIDLY.
 
DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY.  THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY.  VEHICLES CAUGHT IN RISING WATER SHOULD BE
ABANDONED QUICKLY.  MOVE TO HIGHER GROUND.
 
A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT.  IT'S
IMPORTANT TO KNOW WHERE YOU ARE RELATIVE TO STREAMS...RIVERS...OR
CREEKS WHICH CAN BECOME KILLERS IN HEAVY RAINS.  CAMPERS SHOULD
AVOID CAMPING ALONG STREAMS OR CREEKS DURING THREATENING RAINS.
 
 
PETE ALESI

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 10, 1:48 PM PSTFlash Flood WarningMTRMarin117 min

Nearby

Flash Flood Warnings in California, 1992Every flash flood warning in 1992

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.