Alert archive / California / Flash Flood Warnings in 2012
Flash Flood Warning 12, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flash flood warning at Dec 23, 2012, 1:41 PM PST for Sonoma County, 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 outline as issued.
The facts
- Issued
- Dec 23, 2012, 1:41 PM PST (21:41 UTC)
- Expired
- Dec 23, 2012, 4:30 PM PST
- In force
- 3 hr
- 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), 85 km from the middle of the area, began a volume at 21:43 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, 9.7 hours before the alert went out and 62 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
- 5 J/kg
- Mixed-layer CIN
- -19 J/kg
- Mixed-layer LCL
- 833 m above ground
- 0-6 km bulk shear
- 62 kt
- 0-1 km storm-relative helicity
- 178 m²/s²
- 0-3 km storm-relative helicity
- 210 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
803
WGUS56 KMTR 232141
FFWMTR
CAC097-240030-
/O.NEW.KMTR.FF.W.0012.121223T2141Z-121224T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
141 PM PST SUN DEC 23 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 430 PM PST.
* AT 103 PM PST...NWS DOPPLER RADAR AND AUTOMATED RAIN GAGES
INDICATED THAT RAINFALL WILL CONTINUE TO MOVE THROUGH THE AREA INTO
THE AFTERNOON HOURS. SOME PETALUMA AREA STREAM GAGES HAVE NOT YET
CRESTED AND CONTINUE TO RISE, AND A PORTION OF THESE GAGES HAVE
REACHED FLOOD STAGE.
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 3826 12259 3813 12243 3812 12249 3816 12256
3819 12258 3818 12261 3821 12266 3829 12268
$$
STRUDLEY1 follow-up statement
648
WGUS76 KMTR 240030
FFSMTR
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
430 PM PST SUN DEC 23 2012
CAC097-240037-
/O.EXP.KMTR.FF.W.0012.000000T0000Z-121224T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SONOMA CA-
430 PM PST SUN DEC 23 2012
...THE FLASH FLOOD WARNING WILL EXPIRE AT 430 PM PST FOR SONOMA
COUNTY...
RAINFALL HAS GREATLY DIMINISHED OVER THE PETALUMA AREA AND CREEK
LEVELS HAVE FALLEN. THEREFORE THE FLASH FLOOD WARNING FOR THIS AREA
IS BEING ALLOWED TO EXPIRE.
LAT...LON 3826 12259 3813 12243 3812 12249 3816 12256
3819 12258 3818 12261 3821 12266 3829 12268
$$
STRUDLEY/DYKEMAThe office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 23, 8:55 AM PST | Flash Flood Warning | MTR | Sonoma | 4 hr |
| Dec 23, 9:31 AM PST | Flash Flood Watch | MTR | Marin, Napa, Sonoma | 5 hr |
| Dec 23, 2:17 PM PST | River Flood Warning | MTR | Napa | 8 hr |
| Dec 23, 2:17 PM PST | River Flood Warning | MTR | Napa | 11 hr |
| Dec 23, 2:33 PM PST | Small Craft Advisory for Hazardous Seas | MTR | 15 hr | |
| Dec 23, 2:38 PM PST | Flash Flood Warning | MTR | Santa Cruz | 5 hr |
| Dec 23, 3:12 PM PST | Flash Flood Watch | MTR | Santa Cruz | 4 hr |
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.