Alert archive / California / Flash Flood Warnings in 1986

Flash Flood Warning 7, NWS San Francisco Bay Area, CA

February 17, 1986San Mateo County, Santa Clara County, Santa Cruz County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Feb 17, 1986, 12:30 PM PST for San Mateo County, Santa Clara County, Santa Cruz County, California. It was in force for 12 hr.

The area

The counties it named.

The facts

Issued
Feb 17, 1986, 12:30 PM PST (20:30 UTC)
Expired
Feb 18, 1986, 12:00 AM PST
In force
12 hr
Issued by
NWS San Francisco Bay Area, CA
Area
Whole counties

Counties San Mateo County, CA, Santa Clara County, CA, Santa Cruz County, CA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Oakland, CA (KOAK), launched 12:00Z, 8.5 hours before the alert went out and 58 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 1986-02-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 70 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 1986-02-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 141 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
70 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
505 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
141 m²/s²
0-3 km storm-relative helicity
197 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 16, 5:00 PM PSTFlash Flood WarningMTRNapa, Sonoma8 hr
Feb 16, 5:00 PM PSTFlash Flood WarningMTRMarin8 hr
Feb 17, 10:20 AM PSTFlash Flood WarningMTRMarin, Sonoma14 hr
Feb 17, 10:20 AM PSTFlash Flood WarningMTRNapa14 hr
Feb 17, 2:40 PM PSTFlash Flood WarningMTRAlameda, Contra Costa9 hr

Nearby

Flash Flood Warnings in California, 1986Every flash flood warning in 1986

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.