Alert archive / California / Flash Flood Warnings in 2017
Flash Flood Warning 49, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flash flood warning at Feb 9, 2017, 12:15 PM PST for Marin County, California. It was in force for 6 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
- Feb 9, 2017, 12:15 PM PST (20:15 UTC)
- Expired
- Feb 9, 2017, 6:15 PM PST
- In force
- 6 hr
- 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), 106 km from the middle of the area, began a volume at 20:17 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, 8.3 hours before the alert went out and 71 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
- 2 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 838 m above ground
- 0-6 km bulk shear
- 66 kt
- 0-1 km storm-relative helicity
- 182 m²/s²
- 0-3 km storm-relative helicity
- 353 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
725
WGUS56 KMTR 092015
FFWMTR
CAC041-100215-
/O.NEW.KMTR.FF.W.0049.170209T2015Z-170210T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
1215 PM PST THU FEB 9 2017
The National Weather Service in The San Francisco Bay Area has issued
a
* Flash Flood Warning for...
Marin County in northern California...
* Until 615 PM PST Thursday
* At 1210 PM PST, Doppler radar and automated rain gauges indicated
heavy rain falling across much of Marin County. Rain gages in the
Corte Madera Creek watershed (Ross Valley) show rain rates in
excess of 0.5" per hour.
* Stream gages in Ross Valley are rising rapidly and are approaching
flood stages. Due to continuing heavy rain, flash flooding is
expected to begin shortly. In some locations along the northern
Marin/southern Sonoma County, flooding in lowland valleys is
likely already occurring. Flooding is also possible in Mill
Valley and other low lying spots across Marin County in or near to
the warning area.
* Some locations that will experience flooding include...
San Rafael, Mill Valley, San Anselmo, Larkspur, Corte Madera,
Fairfax, Lucas Valley-Marinwood, Tomales, San Geronimo, Kentfield,
Strawberry, and Tamalpais-Homestead Valley.
Excessive rainfall over the warned area will cause mud slides near
steep terrain. The mud slide can consist of rock, mud, vegetation and
other loose materials.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.
A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.
&&
LAT...LON 3830 12300 3832 12297 3831 12292 3832 12292
3832 12290 3828 12285 3818 12278 3812 12268
3802 12245 3781 12245 3782 12254 3791 12269
3809 12285 3809 12283 3814 12289 3830 12301
$$
MWS1 follow-up statement
721
WGUS76 KMTR 092242
FFSMTR
Flash Flood Statement
National Weather Service San Francisco CA
242 PM PST THU FEB 9 2017
CAC041-092251-
/O.CAN.KMTR.FF.W.0049.000000T0000Z-170210T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Marin CA-
242 PM PST THU FEB 9 2017
...THE FLASH FLOOD WARNING FOR MARIN COUNTY IS CANCELLED...
Flood waters have receded in many of the creeks in Marin County.
Flooding is no longer expected to pose a threat from creeks,
although there may be ponding remaining in low lying areas. Please
continue to heed any remaining road closures.
LAT...LON 3830 12300 3832 12297 3831 12292 3832 12292
3832 12290 3828 12285 3818 12278 3812 12268
3802 12245 3781 12245 3782 12254 3791 12269
3809 12285 3809 12283 3814 12289 3830 12301
$$
MWSThe office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 9, 2:20 AM PST | Small Craft Advisory for Rough Bar | MTR | 19 hr | |
| Feb 9, 4:10 AM PST | River Flood Warning | MTR | Napa | 24 hr |
| Feb 9, 11:41 AM PST | Flash Flood Warning | MTR | Marin, Sonoma | 7 hr |
| Feb 9, 12:27 PM PST | Flash Flood Warning | MTR | Sonoma | 6 hr |
| Feb 9, 12:40 PM PST | Flash Flood Warning | MTR | Sonoma | 5 hr |
| Feb 9, 1:21 PM PST | Flash Flood Warning | MTR | Napa | 5 hr |
| Feb 9, 3:04 PM PST | Small Craft Advisory | MTR | 71 hr | |
| Feb 9, 3:36 PM PST | River Flood Warning | MTR | Napa | 23 hr |
Nearby
Flash Flood Warnings in California, 2017Every flash flood warning in 2017
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.