Alert archive / California / Flash Flood Warnings in 1998

Flash Flood Warning 8, NWS San Francisco Bay Area, CA

February 2, 1998Contra Costa County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Feb 2, 1998, 2:30 PM PST for Contra Costa County, California. It was in force for 10 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 2, 1998, 2:30 PM PST (22:30 UTC)
Expired
Feb 3, 1998, 12:00 AM PST
In force
10 hr
Issued by
NWS San Francisco Bay Area, CA
Area
Whole counties

County Contra Costa County, CA

The nearest sounding before it

Oakland, CA (KOAK), launched 12:00Z, 10.5 hours before the alert went out and 31 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 1998-02-02Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Oakland, CA at 12:00Z on 1998-02-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 152 square meters per square second.1939587897117Sfc1 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
787 m above ground
0-6 km bulk shear
99 kt
0-1 km storm-relative helicity
152 m²/s²
0-3 km storm-relative helicity
196 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 2, 12:45 PM PSTFlash Flood WarningMTRSanta Clara, Santa Cruz11 hr
Feb 2, 12:45 PM PSTFlash Flood WarningMTRMonterey11 hr
Feb 2, 2:30 PM PSTFlash Flood WarningMTRAlameda, San Mateo, Santa Clara, Santa Cruz10 hr
Feb 2, 2:30 PM PSTFlash Flood WarningMTRMarin10 hr
Feb 2, 2:30 PM PSTFlash Flood WarningMTRMonterey10 hr
Feb 2, 2:30 PM PSTFlash Flood WarningMTRCity and County of San Francisco10 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.