Alert archive / California / Flash Flood Warnings in 1998
Flash Flood Warning 55, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flash flood warning at Feb 7, 1998, 11:00 PM PST for City and County of San Francisco, 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, 11:00 PM PST (07:00 UTC)
- Expired
- Feb 8, 1998, 2:00 AM PST
- In force
- 3 hr
- Issued by
- NWS San Francisco Bay Area, CA
- Area
- Whole counties
The radar
The San Francisco radar (KMUX), 84 km from the middle of the area, began a volume at 07:03 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, 7.0 hours before the alert went out and 22 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
- 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
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KSFO 080700 FFWSFO CAC001-013-041-053-069-075-081-085-087-055-097-081000- BULLETIN - EAS ACTIVATION REQUESTED REQUESTED NATIONAL WEATHER SERVICE SAN FRANCISCO CA 1100 PM PST SAT FEB 7 1998 ...THE FLASH FLOOD WARNING FOR SANTA CRUZ AND SANTA CLARA COUNTIES HAS BEEN EXTENDED UNTIL 2 AM SUNDAY MORNING... ...THE FLASH FLOOD WARNING FOR THE FOLLOWING COUNTIES HAS BEEN ALLOWED TEXPIRE...ALAMEDA...CONTRA COAST...MARIN...MONTEREY...SAN BENITO...SAN FRANCISCO...SAN MATEO...NAPA AND SONOMA COUNTIES... AT 1045 PM...THE CREEKS AND SMALL STREAMS IN THE BAY AREA AND CENTRAL COAST COUNTIES REMAIN HIGH...THOUGH STREAMS ARE SLOWLY RECEEDING AND THE INTENSITY OF THE RAINSHOWERS HAVE DIMINISHED. RAINFALL RATES ACROSS THE REGION ARE GENERALLY LESS THAN TWO TENTHS OF AN INCH IN THE LAST THREE HOURS...EXCEPT FOR A BAND OF HALF INCH AMOUNTS ACROSS THE SANTA CRUZ MOUNTAINS EXTENDING INTO SANTA CLARA COUNTY. DOPPLER RADAR AND SATELLITE IMAGERY CONTINUE TO SHOW SHOWERS ACROSS THE REGION WITH MOST OF THE CONCENTRATION BEING IN SANTA CRUZ AND SANTA CLARA COUNTIES. THE RAINSHOWERS OVER SANTA CRUZ AND SANTA CLARA COUNTIES ARE TRAINING OVER THE SAME AREAS AND EVEN THOUGH THE SHOWER INTENSITIES HAVE DIMINISHED...PROLONGED DURATION OF ADDITIONAL SHOWER ACTIVITY HAVE RESULTED IN THE EXTENSION OF THE FLASH FLOOD WARNING FOR SANTA CRUZ AND SANTA CLARA COUNTIES THROUGH 2 AM SUNDAY MORNING. DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY BE TO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY. DIAZ
The office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 7, 5:53 PM PST | Severe Thunderstorm Warning | MTR | Santa Clara, Santa Cruz | 37 min |
| Feb 7, 8:00 PM PST | Flash Flood Warning | MTR | Napa, Sonoma | 3 hr |
| Feb 7, 8:00 PM PST | Flash Flood Warning | MTR | City and County of San Francisco, San Mateo | 3 hr |
| Feb 7, 8:00 PM PST | Flash Flood Warning | MTR | Monterey, San Benito, Santa Cruz | 3 hr |
| Feb 7, 8:00 PM PST | Flash Flood Warning | MTR | Alameda, Santa Clara | 3 hr |
| Feb 7, 8:00 PM PST | Flash Flood Warning | MTR | Contra Costa | 3 hr |
| Feb 7, 8:00 PM PST | Flash Flood Warning | MTR | Marin | 3 hr |
| Feb 7, 11:00 PM PST | Flash Flood Warning | MTR | Alameda, San Benito, San Mateo, Santa Clara, Santa Cruz | 3 hr |
| Feb 7, 11:00 PM PST | Flash Flood Warning | MTR | Napa, Sonoma | 3 hr |
| Feb 7, 11:00 PM PST | Flash Flood Warning | MTR | Marin | 3 hr |
| Feb 7, 11:00 PM PST | Flash Flood Warning | MTR | Monterey | 3 hr |
| Feb 7, 11:00 PM PST | Flash Flood Warning | MTR | Contra Costa | 3 hr |
| Feb 8, 6:55 AM PST | Flash Flood Warning | MTR | Santa Clara | 8 hr |
| Feb 8, 1:55 PM PST | Flash Flood Warning | MTR | Santa Clara | 4 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.