Alert archive / California / Flash Flood Warnings in 2017
Flash Flood Warning 2, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 4, 2017, 3:41 AM PST for Sonoma County, California. It was in force for 4 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
- Jan 4, 2017, 3:41 AM PST (11:41 UTC)
- Expired
- Jan 4, 2017, 7:45 AM PST
- In force
- 4 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), 96 km from the middle of the area, began a volume at 11:43 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 00:00Z, 11.7 hours before the alert went out and 88 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 707 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 335 m²/s²
- 0-3 km storm-relative helicity
- 696 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
812
WGUS56 KMTR 041141
FFWMTR
CAC097-041545-
/O.NEW.KMTR.FF.W.0002.170104T1141Z-170104T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
341 AM PST WED JAN 4 2017
The National Weather Service in The San Francisco Bay Area has issued
a
* Flash Flood Warning for...
Central Sonoma County in northern California...
* Until 745 AM PST
* At 339 AM PST, radar indicated heavy rain falling across the
warned area. Steam gages confirm that moderate flood stage has
been reached on the Colgan Creek. Flash flooding is likely
already occurring on Llano Road. Additional rainfall is expected
with further rises on the Colgan Creek and nearby water ways
possible.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Please report flooding to your local law enforcement agency when you
can do so safely.
&&
LAT...LON 3838 12276 3836 12273 3834 12273 3835 12277
3840 12282 3841 12282 3840 12279 3839 12277
$$
DRP2 follow-up statements
369
WGUS76 KMTR 041356
FFSMTR
Flash Flood Statement
National Weather Service San Francisco CA
556 AM PST WED JAN 4 2017
CAC097-041545-
/O.CON.KMTR.FF.W.0002.000000T0000Z-170104T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sonoma CA-
556 AM PST WED JAN 4 2017
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 AM PST FOR
CENTRAL SONOMA COUNTY...
At 553 AM PST, stream gages on the Colgan Creek continue to indicate
flash flooding is likely around Colgan Creek, especially on Llano
Rd. That said, rain rates have dropped off and the stream gage has
now crested. Additional rise from runoff is possible, but the
expected water level trend on Colgan Creek is lower.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Please report flooding to your local law enforcement agency when you
can do so safely.
&&
LAT...LON 3838 12276 3836 12273 3834 12273 3835 12277
3840 12282 3841 12282 3840 12279 3839 12277
$$
DRP597
WGUS76 KMTR 041538
FFSMTR
Flash Flood Statement
National Weather Service San Francisco CA
738 AM PST WED JAN 4 2017
CAC097-041546-
/O.EXP.KMTR.FF.W.0002.000000T0000Z-170104T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sonoma CA-
738 AM PST WED JAN 4 2017
...THE FLASH FLOOD WARNING FOR CENTRAL SONOMA COUNTY WILL EXPIRE AT
745 AM PST...
The heavy rain has ended and flood waters continue to recede.
Flooding is no longer expected to pose a threat. Please continue to
heed any remaining road closures and never drive into flooded
roadways.
LAT...LON 3838 12276 3836 12273 3834 12273 3835 12277
3840 12282 3841 12282 3840 12279 3839 12277
$$
RGASSThe office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 3, 5:31 PM PST | Areal Flood Warning | MTR | Alameda, Contra Costa, Marin, Monterey, Napa, San Benito and 5 more | 6 hr |
| Jan 3, 5:43 PM PST | Areal Flood Advisory | MTR | Alameda, Contra Costa, Marin, Monterey, Napa, San Benito and 5 more | 12 hr |
| Jan 4, 1:08 AM PST | Flash Flood Warning | MTR | Santa Cruz | 3 hr |
| Jan 4, 2:35 AM PST | Small Craft Advisory | MTR | 6 hr | |
| Jan 4, 3:53 AM PST | Flash Flood Warning | MTR | Santa Cruz | 3 hr |
| Jan 4, 4:40 AM PST | Flash Flood Warning | MTR | Monterey | 6 hr |
| Jan 4, 3:30 PM PST | Flash Flood Warning | MTR | Santa Clara | 2 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.