Alert archive / California / Flash Flood Warnings in 2017
Flash Flood Warning 16, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 10, 2017, 12:40 PM PST for Santa Clara 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
- Jan 10, 2017, 12:40 PM PST (20:40 UTC)
- Expired
- Jan 10, 2017, 6:30 PM PST
- In force
- 6 hr
- Issued by
- NWS San Francisco Bay Area, CA
- Area
- Storm-based polygon
- Flood severity
- None
County Santa Clara County, CA
The radar
The San Francisco radar (KMUX), 13 km from the middle of the area, began a volume at 20:42 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, 8.7 hours before the alert went out and 56 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
- 8 J/kg
- Mixed-layer CIN
- -8 J/kg
- Mixed-layer LCL
- 604 m above ground
- 0-6 km bulk shear
- 68 kt
- 0-1 km storm-relative helicity
- 191 m²/s²
- 0-3 km storm-relative helicity
- 263 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
496
WGUS56 KMTR 102040
FFWMTR
CAC085-110230-
/O.NEW.KMTR.FF.W.0016.170110T2040Z-170111T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
1240 PM PST TUE JAN 10 2017
The National Weather Service in The San Francisco Bay Area has issued
a
* Flash Flood Warning for...
Western Santa Clara County in northern California...
* Until 630 PM PST
* At 1235 PM PST, automated stream gages and media reports indicated
that Lexington Reservoir has begun to spill over the spillway and
water levels in Los Gatos Creek have reached recreational pathways
bordering the creek. Flash flooding is beginning to occur, and as
rainfall intensities increase this evening the flash flooding is
likely to become more severe.
* Flooding may not end up being widespread, but poses a dangerous
hazard for paths and roadways near the Los Gatos Creek in the
vicinity of Los Gatos, Campbell, and areas downstream.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.
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 3731 12190 3729 12193 3720 12198 3720 12200
3726 12197 3731 12193
$$
MWS1 follow-up statement
311
WGUS76 KMTR 110226
FFSMTR
Flash Flood Statement
National Weather Service San Francisco CA
626 PM PST TUE JAN 10 2017
CAC085-110231-
/O.EXP.KMTR.FF.W.0016.000000T0000Z-170111T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Santa Clara CA-
626 PM PST TUE JAN 10 2017
...THE FLASH FLOOD WARNING FOR WESTERN SANTA CLARA COUNTY WILL EXPIRE
AT 630 PM PST...
By 6 PM PST, rainfall had diminished in the Santa Cruz Mountains.
However, run-off from recent rainfall continues to result in flooding
of low lying areas. In addition, radar indicates a line of moderate
to heavy rain will move into the Santa Cruz Mountains within the next
hour. Therefore, an Areal Flood Warning will be posted for this
continued flood threat. Please continue to heed any remaining road
closures and remain watchful for rising waters.
LAT...LON 3731 12190 3729 12193 3720 12198 3720 12200
3726 12197 3731 12193
$$The office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 9, 9:10 PM PST | Small Craft Advisory for Rough Bar | MTR | 24 hr | |
| Jan 10, 2:25 AM PST | River Flood Warning | MTR | Napa | 25 hr |
| Jan 10, 2:25 AM PST | River Flood Warning | MTR | Napa | 31 hr |
| Jan 10, 8:38 AM PST | Gale Warning | MTR | 12 hr | |
| Jan 10, 10:56 AM PST | Areal Flood Warning | MTR | Sonoma | 48 hr |
| Jan 10, 11:29 AM PST | Areal Flood Warning | MTR | Monterey, Santa Cruz | 48 hr |
| Jan 10, 12:18 PM PST | Flash Flood Warning | MTR | Sonoma | 6 hr |
| Jan 10, 2:08 PM PST | Flash Flood Warning | MTR | Napa | 6 hr |
| Jan 10, 2:27 PM PST | Flash Flood Warning | MTR | Marin | 6 hr |
| Jan 10, 2:51 PM PST | Areal Flood Warning | MTR | Santa Clara | 36 hr |
| Jan 10, 2:55 PM PST | Areal Flood Advisory | MTR | San Mateo, Santa Clara | 2 hr |
| Jan 10, 3:07 PM PST | Small Craft Advisory | MTR | 60 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.