Alert archive / California / Flash Flood Warnings in 1998

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

February 7, 1998Amador County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Feb 7, 1998, 8:30 AM PST for Amador County, California. It was in force for 6 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, 8:30 AM PST (16:30 UTC)
Expired
Feb 7, 1998, 2:30 PM PST
In force
6 hr
Issued by
NWS San Francisco Bay Area, CA
Area
Whole counties

County Amador County, CA

The radar

The Sacramento radar (KDAX), 90 km from the middle of the area, began a volume at 16:30 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, 4.5 hours before the alert went out and 157 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 1998-02-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 139 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 1998-02-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 174 square meters per square second.19395878Sfc1 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
139 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
532 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
174 m²/s²
0-3 km storm-relative helicity
268 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

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 6, 9:15 PM PSTFlash Flood WarningMTRSan Mateo3 hr
Feb 6, 9:15 PM PSTFlash Flood WarningMTRSonoma3 hr
Feb 7, 8:30 AM PSTFlash Flood WarningMTRRiverside6 hr
Feb 7, 12:05 PM PSTFlash Flood WarningMTRAlameda, San Mateo, Santa Clara, Santa Cruz8 hr
Feb 7, 12:05 PM PSTFlash Flood WarningMTRContra Costa8 hr
Feb 7, 12:05 PM PSTFlash Flood WarningMTRCity and County of San Francisco8 hr
Feb 7, 12:24 PM PSTFlash Flood WarningMTRMonterey, San Benito8 hr
Feb 7, 1:25 PM PSTFlash Flood WarningMTRNapa, Sonoma7 hr
Feb 7, 1:25 PM PSTFlash Flood WarningMTRMarin7 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.