Alert archive / California / Flash Flood Warnings in 2017
Flash Flood Warning 52, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flash flood warning at Feb 9, 2017, 1:21 PM PST for Napa County, California. It was in force for 5 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, 1:21 PM PST (21:21 UTC)
- Expired
- Feb 9, 2017, 6:15 PM PST
- In force
- 5 hr
- Issued by
- NWS San Francisco Bay Area, CA
- Area
- Storm-based polygon
- Flood severity
- None
County Napa County, CA
The radar
The Sacramento radar (KDAX), 62 km from the middle of the area, began a volume at 21:24 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, 9.4 hours before the alert went out and 79 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.
270
WGUS56 KMTR 092121
FFWMTR
CAC055-100215-
/O.NEW.KMTR.FF.W.0052.170209T2121Z-170210T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
121 PM PST THU FEB 9 2017
The National Weather Service in The San Francisco Bay Area has issued
a
* Flash Flood Warning for...
Southwestern Napa County in northern California...
* Until 615 PM PST
* At 120 PM PST, Doppler radar and automated rain gauges indicated
heavy rain falling across the warned area. Numerous stream gages
in the Napa Valley basin are rapidly rising and approaching or
exceeding flood stages. Flash flooding is expected to begin
shortly.
* Some locations that will experience flooding include...
Napa, American Canyon, St. Helena, Calistoga, Yountville, Deer
Park.
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.
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 3859 12248 3854 12242 3854 12237 3851 12233
3848 12232 3848 12238 3844 12232 3840 12227
3837 12224 3833 12221 3827 12222 3816 12222
3816 12234 3818 12234 3822 12233 3830 12239
3835 12240 3843 12242 3847 12247 3850 12249
3852 12249 3855 12255 3859 12262 3866 12262
$$
MWS1 follow-up statement
213
WGUS76 KMTR 092350
FFSMTR
Flash Flood Statement
National Weather Service San Francisco CA
350 PM PST THU FEB 9 2017
CAC055-092358-
/O.CAN.KMTR.FF.W.0052.000000T0000Z-170210T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Napa CA-
350 PM PST THU FEB 9 2017
...THE FLASH FLOOD WARNING FOR SOUTHWESTERN NAPA COUNTY IS
CANCELLED...
The heavy rain has ended and water levels are receding in creeks
tributary to the Napa River. Flooding is still forecast on the
mainstem Napa River in St Helena and at the Napa River near Napa
gaging site. Ths is covered by a separate Flood Warning for the
mainstem river. Please continue to heed any remaining road closures.
LAT...LON 3859 12248 3854 12242 3854 12237 3851 12233
3848 12232 3848 12238 3844 12232 3840 12227
3837 12224 3833 12221 3827 12222 3816 12222
3816 12234 3818 12234 3822 12233 3830 12239
3835 12240 3843 12242 3847 12247 3850 12249
3852 12249 3855 12255 3859 12262 3866 12262
$$
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, 12:15 PM PST | Flash Flood Warning | MTR | Marin | 6 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, 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.