Alert archive / California / Flash Flood Warnings in 1998

Flash Flood Warning 49, NWS San Francisco Bay Area, CA

February 7, 1998Monterey County, San Benito County, Santa Cruz County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Feb 7, 1998, 8:00 PM PST for Monterey County, San Benito County, Santa Cruz 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
Feb 7, 1998, 8:00 PM PST (04:00 UTC)
Expired
Feb 7, 1998, 11:00 PM PST
In force
3 hr
Issued by
NWS San Francisco Bay Area, CA
Area
Whole counties

Counties Monterey County, CA, San Benito County, CA, Santa Cruz County, CA

The radar

The San Francisco radar (KMUX), 71 km from the middle of the area, began a volume at 04:02 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, 4.0 hours before the alert went out and 139 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 1998-02-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 502 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 1998-02-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 137 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
502 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
650 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
137 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.4
Supercell composite
1.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KSFO 080405
FFWSFO
CAC001-013-041-053-069-075-081-085-087-055-097-080700-
 
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
800 PM PST SAT FEB 7 1998
 
THE NATIONAL WEATHER

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 7, 5:53 PM PSTSevere Thunderstorm WarningMTRSanta Clara, Santa Cruz37 min
Feb 7, 8:00 PM PSTFlash Flood WarningMTRNapa, Sonoma3 hr
Feb 7, 8:00 PM PSTFlash Flood WarningMTRCity and County of San Francisco, San Mateo3 hr
Feb 7, 8:00 PM PSTFlash Flood WarningMTRAlameda, Santa Clara3 hr
Feb 7, 8:00 PM PSTFlash Flood WarningMTRContra Costa3 hr
Feb 7, 8:00 PM PSTFlash Flood WarningMTRMarin3 hr
Feb 7, 11:00 PM PSTFlash Flood WarningMTRAlameda, San Benito, San Mateo, Santa Clara, Santa Cruz3 hr
Feb 7, 11:00 PM PSTFlash Flood WarningMTRNapa, Sonoma3 hr
Feb 7, 11:00 PM PSTFlash Flood WarningMTRCity and County of San Francisco3 hr
Feb 7, 11:00 PM PSTFlash Flood WarningMTRMarin3 hr
Feb 7, 11:00 PM PSTFlash Flood WarningMTRMonterey3 hr
Feb 7, 11:00 PM PSTFlash Flood WarningMTRContra Costa3 hr
Feb 8, 6:55 AM PSTFlash Flood WarningMTRSanta Clara8 hr
Feb 8, 1:55 PM PSTFlash Flood WarningMTRSanta Clara4 hr

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.