Alert archive / California / Flash Flood Warnings in 1997

Flash Flood Warning 39, NWS San Francisco Bay Area, CA

January 25, 1997City and County of San Francisco, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 25, 1997, 4:00 AM PST for City and County of San Francisco, California. It was in force for 8 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, 4:00 AM PST (12:00 UTC)
Expired
Jan 25, 1997, 12:00 PM PST
In force
8 hr
Issued by
NWS San Francisco Bay Area, CA
Area
Whole counties

County City and County of San Francisco, CA

The radar

The San Francisco radar (KMUX), 84 km from the middle of the area, began a volume at 12:01 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

Vandenberg AFB, CA (KVBG), launched 12:00Z, 0.0 hours before the alert went out and 381 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 251200
FFWSFO
CAC041-075-055-097-252000-
 
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
400 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
 
   ...MARIN COUNTY...SAN FRANCISCO COUNTY
 
IN NORTH CENTRAL CALIFORNIA
 
   ...NAPA COUNTY...SONOMA COUNTY
 
HEAVY RAIN IS BEGINNING TO MOVE INTO THE NORTH BAY COUNTIES EARLY THIS
MORNING. SO FAR...SONOMA COUNTY HAS RECEIVED 1 TO 1.5 INCHES OVER THE
PAST 3 HOURS. RAIN RATES HAVE BEEN .3 TO .5 OVER THE PAST TWO HOURS. THE
PACIFIC FRONT IS STILL OFF SHORE...BUT WILL CONTINUE TO MOVE SLOWLY
EASTWARD THROUGHOUT THE MORNING HOURS ACROSS THE WARNING AREA. HEAVY
RAIN WILL CONTINUE OVER THE WARNING AREA FOR THE NEXT 3 TO 4 HOURS.
 
CREEKS AND SMALL RIVERS IN THE WARNING AREA WILL RISE AND BECOME BANKFUL
QUICKLY. ALSO EXPECT WIDESPREAD URBAN FLOODING AND MUDSLIDES IN THE
WARNING AREA THIS MORNING.
 
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.
 
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.
 
COX

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 WarningMTRMarin8 hr
Jan 25, 5:35 AM PSTFlash Flood WarningMTRSan Mateo, Santa Clara, Santa Cruz6 hr
Jan 25, 5:35 AM PSTFlash Flood WarningMTRAlameda, Contra Costa6 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.