Alert archive / California / Flash Flood Warnings in 2017
Flash Flood Warning 29, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 20, 2017, 7:08 AM 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 20, 2017, 7:08 AM PST (15:08 UTC)
- Expired
- Jan 20, 2017, 1:00 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), 23 km from the middle of the area, began a volume at 15:09 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, 3.1 hours before the alert went out and 83 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
- 774 m above ground
- 0-6 km bulk shear
- 73 kt
- 0-1 km storm-relative helicity
- 501 m²/s²
- 0-3 km storm-relative helicity
- 746 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
549
WGUS56 KMTR 201508
FFWMTR
CAC085-202100-
/O.NEW.KMTR.FF.W.0029.170120T1508Z-170120T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
708 AM PST FRI JAN 20 2017
The National Weather Service in The San Francisco Bay Area has issued
a
* Flash Flood Warning for...
Southeastern Santa Clara County in northern California...
* Until 100 PM PST
* At 703 AM PST, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Flash
flooding is expected to begin shortly.
* This warning is being issued specifically for West Little Llagas
Creek through Morgan Hill. The stream gage on W. Little Llagas is
indicating rapidly rising water levels that are approaching flood
stage and are very likely to exceed it in response to additional
rainfall this morning. Weather radar shows additional convective
activity headed over the Santa Cruz Mountains towards Morgan Hill.
* Other areas in the vicinity of Morgan Hill may experience
flooding. Additional Flash Flood Warnings or Areal Flood Warnings
could be issued is flooding concerns expand.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
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 3714 12161 3711 12160 3710 12163 3711 12167
3716 12172
$$
MWS1 follow-up statement
051
WGUS76 KMTR 201659
FFSMTR
Flash Flood Statement
National Weather Service San Francisco CA
859 AM PST FRI JAN 20 2017
CAC085-201707-
/O.CAN.KMTR.FF.W.0029.000000T0000Z-170120T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Santa Clara CA-
859 AM PST FRI JAN 20 2017
...THE FLASH FLOOD WARNING FOR SOUTHEASTERN SANTA CLARA COUNTY IS
CANCELLED...
Water levels have receded in West Little Llagas Creek near
MorganHill, after coming very close to reaching flood stage.
Sporadic showers are expected through the day, but most of the
rainfall has passed and additional runoff is not expected to be
problematic. Please continue to heed any remaining road closures.
LAT...LON 3714 12161 3711 12160 3710 12163 3711 12167
3716 12172
$$
MWSThe office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 19, 9:01 PM PST | Gale Warning | MTR | 10 hr | |
| Jan 19, 9:01 PM PST | Small Craft Advisory | MTR | 42 hr | |
| Jan 20, 1:26 AM PST | Areal Flood Advisory | MTR | Marin, Sonoma | 3 hr |
| Jan 20, 3:02 AM PST | Special Marine Warning | MTR | 43 min | |
| Jan 20, 3:39 AM PST | Special Weather Statement | MTR | San Mateo | 36 min |
| Jan 20, 4:07 AM PST | Special Marine Warning | MTR | 23 min | |
| Jan 20, 4:14 AM PST | Special Weather Statement | MTR | Alameda, Contra Costa, San Mateo | 31 min |
| Jan 20, 4:49 AM PST | Flash Flood Warning | MTR | Sonoma | 4 hr |
| Jan 20, 5:27 AM PST | Areal Flood Advisory | MTR | San Mateo, Santa Clara, Santa Cruz | 3 hr |
| Jan 20, 6:38 AM PST | Flash Flood Warning | MTR | Santa Cruz | 6 hr |
| Jan 20, 7:31 AM PST | Areal Flood Warning | MTR | Santa Cruz | 12 hr |
| Jan 20, 7:55 AM PST | Areal Flood Warning | MTR | Sonoma | 18 hr |
| Jan 20, 12:20 PM PST | Flash Flood Warning | MTR | San Benito | 4 hr |
| Jan 20, 12:51 PM PST | High Wind Watch | MTR | Alameda, Contra Costa, Marin, Monterey, Napa, San Benito and 5 more | 15 hr |
| Jan 20, 1:27 PM PST | Flash Flood Watch | MTR | Alameda, Contra Costa, Marin, Monterey, Napa, San Benito and 5 more | 3 days |
| Jan 20, 2:33 PM PST | Gale Watch | MTR | 14 hr | |
| Jan 20, 2:33 PM PST | Gale Warning | MTR | 42 hr | |
| Jan 20, 3:51 PM PST | Areal Flood Advisory | MTR | San Benito, Santa Clara | 70 hr |
| Jan 20, 3:56 PM PST | Areal Flood Warning | MTR | San Benito, Santa Clara | 72 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.