Alert archive / California / Flash Flood Warnings in 2012
Flash Flood Warning 10, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flash flood warning at Dec 2, 2012, 8:47 AM PST for Sonoma County, California. It was in force for 88 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Dec 2, 2012, 8:47 AM PST (16:47 UTC)
- Expired
- Dec 2, 2012, 10:15 AM PST
- In force
- 88 min
- Issued by
- NWS San Francisco Bay Area, CA
- Area
- Storm-based polygon
- Flood severity
- None
County Sonoma County, CA
The radar
The Sacramento radar (KDAX), 87 km from the middle of the area, began a volume at 16:47 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, 4.8 hours before the alert went out and 69 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
- 58 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 529 m above ground
- 0-6 km bulk shear
- 61 kt
- 0-1 km storm-relative helicity
- 203 m²/s²
- 0-3 km storm-relative helicity
- 348 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
The text
As transmitted, in the capitals the NWS used until 2016.
596 WGUS56 KMTR 021647 FFWMTR CAC097-021815- /O.NEW.KMTR.FF.W.0010.121202T1647Z-121202T1815Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE SAN FRANCISCO CA 847 AM PST SUN DEC 2 2012 THE NATIONAL WEATHER SERVICE IN THE SAN FRANCISCO BAY AREA HAS ISSUED A * FLASH FLOOD WARNING FOR... SONOMA COUNTY IN WESTERN CALIFORNIA... THIS INCLUDES THE CITY OF PETALUMA... * UNTIL 1015 AM PST. * AT 842 AM PST...NWS DOPPLER RADAR AND AUTOMATED RAIN GAGES INDICATED HEAVY RAIN CONTINUING OVER PETALUMA. WILLOW BROOK NEAR PENNGROVE PARK CONTINUES TO FLOOD. FLOODING IS LIKELY TO INCREASE WITH THE CONTINUED HEAVY RAIN. * THE STORM PRODUCING WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS OF THE INDICATED COUNTY. A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS IMMINENT. RUNOFF FROM HEAVY RAINFALL WILL CAUSE LOCALIZED FLOODING OF SMALL CREEKS AND STREAMS AS WELL AS ROADWAYS...UNDERPASSES AND OTHER LOW LYING SPOTS. DO NOT ATTEMPT TO CROSS SWIFTLY FLOWING WATER OR WATER OF UNKNOWN DEPTH. TURN AROUND...DONT DROWN. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING. TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE. LAT...LON 3828 12267 3829 12261 3822 12253 3819 12263 $$ JOHNSON
1 follow-up statement
535 WGUS76 KMTR 021812 FFSMTR FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE SAN FRANCISCO CA 1012 AM PST SUN DEC 2 2012 CAC097-021819- /O.EXP.KMTR.FF.W.0010.000000T0000Z-121202T1815Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ SONOMA CA- 1012 AM PST SUN DEC 2 2012 ...THE FLASH FLOOD WARNING WILL EXPIRE AT 1015 AM PST FOR SONOMA COUNTY... HEAVY RAIN HAS DIMINISHED AND THE IMMEDIATE THREAT FOR FLASH FLOODING HAS ENDED. ADDITIONAL RISES IN CREEKS AND STREAMS ARE NO LONGER EXPECTED TODAY. PEOPLE NEAR STREAMS ARE STILL URGED TO USE CAUTION AS THEY MAY BE MUCH HIGHER THAN NORMAL. LAT...LON 3828 12267 3829 12261 3822 12253 3819 12263 $$ MM
The office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 1, 4:44 PM PST | River Flood Watch | MTR | Sonoma | 6 days |
| Dec 2, 1:28 AM PST | Gale Warning | MTR | 11 hr | |
| Dec 2, 6:35 AM PST | Flash Flood Warning | MTR | Napa, Sonoma | 85 min |
| Dec 2, 6:54 AM PST | Areal Flood Advisory | MTR | Marin, Napa, Sonoma | 3 hr |
| Dec 2, 7:19 AM PST | Areal Flood Advisory | MTR | Alameda, Contra Costa, Marin, City and County of San Francisco, San Mateo, Santa Clara and 1 more | 3 hr |
| Dec 2, 7:41 AM PST | Flash Flood Warning | MTR | Sonoma | 64 min |
| Dec 2, 8:15 AM PST | Flash Flood Warning | MTR | Santa Clara, Santa Cruz | 2 hr |
| Dec 2, 8:42 AM PST | Flash Flood Warning | MTR | Marin | 93 min |
| Dec 2, 9:20 AM PST | Areal Flood Advisory | MTR | Monterey, San Benito, San Mateo, Santa Clara, Santa Cruz | 3 hr |
| Dec 2, 10:21 AM PST | Areal Flood Advisory | MTR | Alameda, Santa Clara | 54 min |
Nearby
Flash Flood Warnings in California, 2012Every flash flood warning in 2012
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.