Alert archive / California / Flash Flood Warnings in 1998

Flash Flood Warning 61, NWS San Francisco Bay Area, CA

February 8, 1998Santa Clara County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Feb 8, 1998, 5:55 PM PST for Santa Clara County, California. It was in force for 5 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
Feb 8, 1998, 5:55 PM PST (01:55 UTC)
Expired
Feb 8, 1998, 11:00 PM PST
In force
5 hr
Issued by
NWS San Francisco Bay Area, CA
Area
Whole counties

County Santa Clara County, CA

The radar

The San Francisco radar (KMUX), 20 km from the middle of the area, began a volume at 01:55 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, 1.9 hours before the alert went out and 71 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 1998-02-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 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 00:00Z on 1998-02-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 square meters per square second.193958Sfc1 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
6 J/kg
Mixed-layer CIN
-105 J/kg
Mixed-layer LCL
586 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
118 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 090159 COR
FFWSFO
CAC085-090700-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING CORRECTION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
555 PM PST SUN FEB 8 1998

THE NATIONAL WEATHER SERVICE IN SAN FRANCISCO HAS EXTENDED THE 
FLASH FLOOD WARNING EFFECTIVE UNTIL 1100 PM PST
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN CENTRAL CALIFORNIA
 
   ...NORTH CENTRAL SANTA CLARA COUNTY
 
...A FLASH FLOOD WARNING HAS BEEN EXTENDED BY THE NATIONAL WEATHER
SERVICE FOR NORTH CENTRAL SANTA CLARA COUNTY THROUGH 11 PM TODAY...
 
ANDERSON RESERVOIR CONTINUES TO SPILL THIS AFTERNOON. AT 530
PM...THE RESERVOIR WAS A LITTLE OVER THREE FEET ABOVE THE SPILLWAY.
COYOTE CREEK AND ASSOCIATED TRIBUTARIES ARE RISING AND WILL CONTINUE
TO RISE THIS EVENING. STREAM GAUGE AND SPOTTER REPORTS INDICATE
COYOTE CREEK NEAR EDENVALE HAS REACHED BANKFULL...WHILE COYOTE CREEK
NEAR MADRONE IS JUST BELOW BANKFULL. SATELLITE IMAGERY AND RADAR
INDICATE MOST OF THE RAIN HAS ENDED.

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.

Nearby

Flash Flood Warnings in California, 1998Every flash flood warning in 1998

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.