Alert archive / California / Flash Flood Warnings in 1997

Flash Flood Warning 20, NWS San Francisco Bay Area, CA

January 1, 1997San Mateo County, Santa Clara County, Santa Cruz County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 1, 1997, 7:00 PM PST for San Mateo County, Santa Clara County, Santa Cruz County, California. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jan 1, 1997, 7:00 PM PST (03:00 UTC)
Expired
Jan 1, 1997, 11:00 PM PST
In force
4 hr
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 radar

The San Francisco radar (KMUX), 14 km from the middle of the area, began a volume at 03:01 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Oakland, CA (KOAK), launched 00:00Z, 3.0 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 00:00Z on 1997-01-02Temperature 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 00:00Z on 1997-01-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 216 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
533 m above ground
0-6 km bulk shear
77 kt
0-1 km storm-relative helicity
216 m²/s²
0-3 km storm-relative helicity
322 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 020257 RRA
FFWSFO
CAC081-085-087-020700-
 
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
700 PM PST WED JAN 1 1997
 
THE NATIONAL WEATHER SERVICE IN SAN FRANCISCO HAS EXTENDED THE 
FLASH FLOOD WARNING EFFECTIVE UNTIL 11 PM PST 
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN CENTRAL CALIFORNIA
 
...SOUTHWESTERN SAN MATEO COUNTY...SANTA CRUZ COUNTY...AND WESTERN 
   SANTA CLARA COUNTY...
 
AT 7 PM MODERATE TO HEAVY RAIN CONTINUED ACROSS SANTA CRUZ...
SOUTHWESTERN SAN MATEO...AND SANTA CLARA COUNTIES.  CREEKS AND RIVERS 
WERE RUNNING BANKFULL OR FLOODING THROUGHOUT THIS AREA.  AT 6 PM THE
SAN LORENZO RIVER AT FELTON WAS AT 16.8 FEET AND RISING.  SOQUEL
CREEK WAS AROUND 13 FEET AND RISING.  AT 630 PM CORRALITOS CREEK AT
FREEDOM WAS RISING RAPIDLY AT A STAGE OF 12.4 FEET.

OTHER PROBLEM CREEKS INCLUDE LLAGAS CREEK BETWEEN MORGAN HILL AND
GILROY..AND PESCADERO CREEK IN SOUTHWESTERN SAN MATEO COUNTY.  STREET
FLOODING HAS ALSO BEEN REPORTED IN MORGAN HILL AND GILROY.
 
MODERATE TO HEAVY RAINFALL WILL CONTINUE OVER THE WARNING AREA UNTIL
AT LEAST 11 PM...ESPECIALLY IN THE MOUNTAINS.  DURING THE LAST 24
HOURS RAINFALL TOTALS IN THE SANTA CRUZ MOUNTAINS...AROUND UVAS
RESERVOIR...AND IN THE MORGAN HILL-GILROY AREA HAVE RANGED FROM FOUR
TO SEVEN INCHES.     

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 SATFELY.  VEHICLES CAUGHT IN RISING WATER SHOULD BE
ABANDONED QUICKLY.  MOVE TO HIGHER GROUND.  MUDSLIDES ARE ALSO
POSSIBLE IN THE WARNING AREA.
 
MARKKANEN

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 1, 5:03 PM PSTFlash Flood WarningMTRSanta Clara117 min
Jan 1, 7:22 PM PSTFlash Flood WarningMTRSan Luis Obispo6 hr
Jan 1, 10:59 PM PSTFlash Flood WarningMTRSan Mateo, Santa Clara, Santa Cruz3 hr
Jan 2, 5:52 AM PSTFlash Flood WarningMTRSan Mateo, Santa Clara, Santa Cruz3 hr
Jan 2, 5:52 AM PSTFlash Flood WarningMTRAlameda, Contra Costa3 hr
Jan 2, 11:45 AM PSTFlash Flood WarningMTRAlameda, San Mateo, Santa Clara, Santa Cruz4 hr
Jan 2, 11:45 AM PSTFlash Flood WarningMTRMonterey4 hr
Jan 2, 11:45 AM PSTFlash Flood WarningMTRContra Costa4 hr

Nearby

Flash Flood Warnings in California, 1997Every flash flood warning in 1997

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; radar from the NEXRAD Level II archive.