Alert archive / California / Flash Flood Warnings in 1997

Flash Flood Warning 18, NWS San Francisco Bay Area, CA

January 1, 1997San Mateo County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 1, 1997, 3:55 PM PST for San Mateo 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, 3:55 PM PST (23:55 UTC)
Expired
Jan 1, 1997, 7:00 PM PST
In force
3 hr
Issued by
NWS San Francisco Bay Area, CA
Area
Whole counties

County San Mateo County, CA

The radar

The San Francisco radar (KMUX), 51 km from the middle of the area, began a volume at 23:54 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, 11.9 hours before the alert went out and 35 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 012354
FFWSFO
CAC053-081-087-020300-
 
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
355 PM PST WED JAN 1 1997
 
THE NATIONAL WEATHER SERVICE IN SAN FRANCISCO HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  700 PM PST
FOR PEOPLE IN THE FOLLOWING LOCATIONSS...
 
IN CENTRAL CALIFORNIA
 
   ...WESTERN MONTEREY COUNTY...SOUTHWESTERN SAN MATEO COUNTY
   ...SANTA CRUZ COUNTY
 
HEAVY RAIN IS CONTINUING OVER SOUTHWESTERN SAN MATEO AND SANTA CRUZ
COUNTIES. AT 345PM...RADAR CONTINUES TO SHOW BANDS OF HEAVY RAIN MOVING
ACROSS THESE COUNTIES OVER THE PAST TWO HOURS. MORE HEAVY RAIN IS
EXPECTED FOR THE NEXT TWO HOURS. MANY CREEKS AND SMALL RIVERS REMAIN AT
BANKFULL. AT 330PM...THE SAN LORENZO RIVER HAD A STAGE OF 16.5
FEET...THE CORRALITOS CREEK HAD A STAGE OF 9.0 FEET AND SOQUEL CREEK
HAD A STAGE OF 10.8 FEET.
 
AT 330PM IN MONTEREY COUNTY...THE BIG SUR HAD A STAGE OF 10.5 FEET AND
THE ARROYO SECO HAD A STAGE OF 12.5 FEET AND RISING FAST. THE CARMEL
RIVER AT ROSIES BRIDGE HAD A STAGE OF 6.2 FEET AT 330PM. THE CARMEL IS
EXPECTED TO RISE ANOTHER FOOT AT ROSIES...BUT WELL WITHIN ITS BANKS.
 
DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVBERS 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/MILLER

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 WarningMTRAlameda, Contra Costa3 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

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.