Alert archive / California / Flash Flood Warnings in 1997

Flash Flood Warning 13, NWS San Francisco Bay Area, CA

January 1, 1997Alameda County, Contra Costa County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 1, 1997, 10:40 AM PST for Alameda County, Contra Costa County, California. It was in force for 3 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, 10:40 AM PST (18:40 UTC)
Expired
Jan 1, 1997, 2:00 PM PST
In force
3 hr
Issued by
NWS San Francisco Bay Area, CA
Area
Whole counties

Counties Alameda County, CA, Contra Costa County, CA

The radar

The San Francisco radar (KMUX), 70 km from the middle of the area, began a volume at 18:39 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 12:00Z, 6.7 hours before the alert went out and 24 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 1997-01-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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 1997-01-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 359 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
503 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
359 m²/s²
0-3 km storm-relative helicity
515 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 KSFO 011841
FFWSFO
CAC001-013-041-081-085-087-055-097-012200-
 
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1040 AM PST WED JAN 1 1997
 
THE NATIONAL WEATHER SERVICE IN SAN FRANCISCO HAS EXTENDED
THE FLASH FLOOD WARNINGS UNTIL 200 PM PST FOR PEOPLE IN THE
FOLLOWING LOCATIONS...
 
IN CENTRAL CALIFORNIA
 
   ...ALAMEDA COUNTY...CONTRA COSTA COUNTY...MARIN COUNTY
   ...SOUTHWESTERN SAN MATEO COUNTY...SANTA CRUZ COUNTY
   ...SANTA CLARA COUNTY...
 
IN NORTH CENTRAL CALIFORNIA
 
   ...NAPA COUNTY...SONOMA COUNTY
 
NOTE...THE FLASH FLOOD WARNING FOR WESTERN SANTA CLARA COUNTY HAS
BEEN EXPANDED TO INCLUDE ALL OF SANTA CLARA COUNTY...
 
MODERATE TO HEAVY RAINS CONTINUE OVER MUCH OF THE SAN FRANCISCO BAY
REGION. AT 1030 AM PST RADAR INDICATED THE HEAVIEST RAIN OVER SAN
MATEO...SANTA CRUZ AND ALAMEDA COUNTIES. RADAR AND SATELLITE INDICATE
THAT AREAS OF MODERATE TO HEAVY RAINS WILL CONTINUE OVER THE NEXT
SEVERAL HOURS.
 
IN SANTA CRUZ COUNTY THE SAN LORENZO RIVER IS CURRENTLY AT 13.8 FEET
WHICH IS LESS THAN A HALF FOOT BELOW BANKFUL. SOME OF THE CITIES
EFFECTED ARE: BOULDER CREEK...FELTON AND BEN LOMOND.
 
IN SANTA CLARA COUNTY THE WEST LITTLE LLAGAS IS OVER ITS BANKS
AND FLOODING STREETS IN DOWNTOWN MORGAN HILL.
 
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.
 
 
DYKEMA

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 1, 1:20 AM PSTFlash Flood WarningMTRSan Mateo, Santa Clara, Santa Cruz6 hr
Jan 1, 2:42 AM PSTFlash Flood WarningMTRNapa6 hr
Jan 1, 7:18 AM PSTFlash Flood WarningMTRAlameda, Contra Costa3 hr
Jan 1, 7:31 AM PSTFlash Flood WarningMTRSan Mateo, Santa Clara, Santa Cruz4 hr
Jan 1, 8:25 AM PSTFlash Flood WarningMTRSonoma4 hr
Jan 1, 8:25 AM PSTFlash Flood WarningMTRMarin4 hr
Jan 1, 8:25 AM PSTFlash Flood WarningMTRNapa4 hr
Jan 1, 9:00 AM PSTFlash Flood WarningMTRMonterey3 hr
Jan 1, 9:00 AM PSTFlash Flood WarningMTRAlameda, Contra Costa3 hr
Jan 1, 9:00 AM PSTFlash Flood WarningMTRSan Mateo, Santa Clara, Santa Cruz3 hr
Jan 1, 10:40 AM PSTFlash Flood WarningMTRSan Mateo, Santa Clara, Santa Cruz3 hr
Jan 1, 10:40 AM PSTFlash Flood WarningMTRMarin, Napa, Sonoma3 hr
Jan 1, 11:30 AM PSTFlash Flood WarningMTRMonterey5 hr
Jan 1, 2:15 PM PSTFlash Flood WarningMTRSan Mateo, Santa Cruz2 hr
Jan 1, 3:55 PM PSTFlash Flood WarningMTRMonterey, Santa Cruz3 hr
Jan 1, 3:55 PM PSTFlash Flood WarningMTRSan Mateo3 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.