Alert archive / California / Flash Flood Warnings in 2012
Flash Flood Warning 9, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flash flood warning at Dec 2, 2012, 8:42 AM PST for Marin County, California. It was in force for 93 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, 8:42 AM PST (16:42 UTC)
- Expired
- Dec 2, 2012, 10:15 AM PST
- In force
- 93 min
- Issued by
- NWS San Francisco Bay Area, CA
- Area
- Storm-based polygon
- Flood severity
- None
County Marin County, CA
The radar
The Sacramento radar (KDAX), 100 km from the middle of the area, began a volume at 16:43 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, 4.7 hours before the alert went out and 55 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.
883
WGUS56 KMTR 021642
FFWMTR
CAC041-021815-
/O.NEW.KMTR.FF.W.0009.121202T1642Z-121202T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
842 AM PST SUN DEC 2 2012
THE NATIONAL WEATHER SERVICE IN THE SAN FRANCISCO BAY AREA HAS
ISSUED A
* FLASH FLOOD WARNING FOR...
MARIN COUNTY IN WESTERN CALIFORNIA...
* UNTIL 1015 AM PST.
* AT 837 AM PST...NWS DOPPLER RADAR AND AUTOMATED RAIN GAGES
INDICATED RAINFALL UP TO 2 INCHES HAS FALLEN THIS MORNING.
ADDITIONAL RAINFALL OF UP TO AN INCH IS POSSIBLE IN THE NEXT HOUR.
SHARP RISES ON CORTE MADERA CREEK HAVE LEAD TO FLOODING NORTH OF
KENTFIELD. ADDITIONAL FLOODING WILL OCCUR WITH HEAVY RAIN FALLING.
* 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.
IT IS IMPORTANT FOR CAMPERS AND HIKERS TO KNOW WHERE THEY ARE
RELATIVE TO CREEKS...STREAMS...OR RIVERS WHICH CAN BECOME DANGEROUS
IN HEAVY RAINS. BE PARTICULARLY AWARE IN HILLY TERRAIN WHERE MANY LOW
WATER CROSSINGS CAN QUICKLY BECOME KILLERS.
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 3806 12283 3816 12279 3817 12276 3817 12268
3814 12259 3805 12256 3797 12251 3791 12256
3787 12259
$$
JOHNSON1 follow-up statement
084
WGUS76 KMTR 021809
FFSMTR
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1009 AM PST SUN DEC 2 2012
CAC041-021815-
/O.EXP.KMTR.FF.W.0009.000000T0000Z-121202T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MARIN CA-
1009 AM PST SUN DEC 2 2012
...THE FLASH FLOOD WARNING WILL EXPIRE AT 1015 AM PST FOR MARIN
COUNTY...
HEAVY RAIN HAS DIMINISHED AND THE IMMEDIATE THREAT FOR FLASH FLOODING
HAS ENDED. ADDITIONAL RISES IN CREEKS AND STREAMS ARE NO LONGER
EXPECTED TODAY. PEOPLE NEAR STREAMS ARE STILL URGED TO USE CAUTION
AS THEY MAY BE MUCH HIGHER THAN NORMAL.
LAT...LON 3806 12283 3816 12279 3817 12276 3817 12268
3814 12259 3805 12256 3797 12251 3791 12256
3787 12259
$$
MMThe 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, 8:47 AM PST | Flash Flood Warning | MTR | Sonoma | 88 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.