Alert archive / California / Flash Flood Warnings in 1998
Flash Flood Warning 41, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flash flood warning at Feb 7, 1998, 12:05 PM PST for 4 counties in California. It was in force for 8 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, 12:05 PM PST (20:05 UTC)
- Expired
- Feb 7, 1998, 8:00 PM PST
- In force
- 8 hr
- Issued by
- NWS San Francisco Bay Area, CA
- Area
- Whole counties
Counties Alameda County, CA, San Mateo County, CA, Santa Clara County, CA, Santa Cruz County, CA
The radar
The San Francisco radar (KMUX), 22 km from the middle of the area, began a volume at 20:09 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, 8.1 hours before the alert went out and 47 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.
- 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
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KSFO 072011 FFWSFO CAC001-013-075-081-085-087-080400- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE SAN FRANCISCO CA 1205 PM PST SAT FEB 7 1998 THE NATIONAL WEATHER SERVICE IN SAN FRANCISCO HAS ISSUED A FLASH FLOOD WARNING EFFECTIVE UNTIL 800 PM PST FOR PEOPLE IN THE FOLLOWING LOCATIONSS... IN CENTRAL CALIFORNIA ...ALAMEDA COUNTY...CONTRA COSTA COUNTY...SAN FRANCISCO COUNTY ...SAN MATEO COUNTY...SANTA CLARA COUNTY...SANTA CRUZ COUNTY HEAVY RAINFALL OVER THE PAST TWO HOURS HAS CAUSED STREAMS IN THE AREA TO RISE RAPIDLY. RAINFALL RATES ARE BETWEEN THREE QUARTERS OF AN INCH TO 1 1/4 INCH IN THE LAST HOUR. MORE HEAVY SHOWERS AND THUNDERSTORMS ARE MOVING ONSHORE. THESE SHOWERS WILL MOVE THROUGH THE REGION DURING EARLY AFTERNOON HOURS. THE HEAVY RAINS WILL DECREASE LATER THIS AFTERNOON. 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.
The office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 6, 9:15 PM PST | Flash Flood Warning | MTR | San Mateo | 3 hr |
| Feb 6, 9:15 PM PST | Flash Flood Warning | MTR | Sonoma | 3 hr |
| Feb 7, 8:30 AM PST | Flash Flood Warning | MTR | Amador | 6 hr |
| Feb 7, 8:30 AM PST | Flash Flood Warning | MTR | Riverside | 6 hr |
| Feb 7, 12:05 PM PST | Flash Flood Warning | MTR | Contra Costa | 8 hr |
| Feb 7, 12:05 PM PST | Flash Flood Warning | MTR | City and County of San Francisco | 8 hr |
| Feb 7, 12:24 PM PST | Flash Flood Warning | MTR | Monterey, San Benito | 8 hr |
| Feb 7, 1:25 PM PST | Flash Flood Warning | MTR | Napa, Sonoma | 7 hr |
| Feb 7, 1:25 PM PST | Flash Flood Warning | MTR | Marin | 7 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.