Alert archive / California / Flash Flood Warnings in 1997

Flash Flood Warning 42, NWS San Francisco Bay Area, CA

January 25, 1997Alameda County, Contra Costa County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 25, 1997, 5:35 AM PST for Alameda County, Contra Costa County, California. It was in force for 6 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 25, 1997, 5:35 AM PST (13:35 UTC)
Expired
Jan 25, 1997, 12:00 PM PST
In force
6 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 13:34 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

Vandenberg AFB, CA (KVBG), launched 12:00Z, 1.6 hours before the alert went out and 363 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, Vandenberg AFB, CA at 12:00Z on 1997-01-25Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Vandenberg AFB, CA at 12:00Z on 1997-01-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 208 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
837 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
208 m²/s²
0-3 km storm-relative helicity
275 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 251340
FFWSFO
CAC001-013-081-085-087-252000-
 
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
535 AM PST SAT JAN 25 1997
 
THE NATIONAL WEATHER SERVICE IN SAN FRANCISCO HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL NOON PST
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN CENTRAL CALIFORNIA
 
   ...ALAMEDA COUNTY...CONTRA COSTA COUNTY...SAN MATEO COUNTY
   ...SANTA CLARA COUNTY...SANTA CRUZ COUNTY.
 
MODERATE TO HEAVY RAIN FALLING ON ALREADY SATURATED GROUND WILL
CAUSE STREAMS TO RAPIDLY RISE TO BANKFULL OR ABOVE THIS MORNING IN
THE WARNING AREA.  THREE TO FIVE TENTHS OF AN INCH OF RAIN FELL IN THE
WARNING AREA BETWEEN 3 AND 5 AM...WITH SIMILAR TOTALS EXPECTED DURING
THE NEXT FEW HOURS.
 
WIDESPREAD URBAN FLOODING WILL OCCUR IN THE WARNING AREA...ALONG WITH
NUMEROUS MUDSLIDES.  THESE PROBLEMS ARE LIKELY TO RESULT IN ROAD
CLOSURES.
 
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE
THE DANGERS OF FLOODS AND FLASH FLOODS.  IF FLASH FLOODING IS
OBSERVED...ACT QUICKLY.  MOVE UP TO ESCAPE FLOOD WATERS.  DO
NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.
 
MARKKANEN

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 25, 4:00 AM PSTFlash Flood WarningMTRNapa, Sonoma8 hr
Jan 25, 4:00 AM PSTFlash Flood WarningMTRCity and County of San Francisco8 hr
Jan 25, 4:00 AM PSTFlash Flood WarningMTRMarin8 hr
Jan 25, 5:35 AM PSTFlash Flood WarningMTRSan Mateo, Santa Clara, Santa Cruz6 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.