Alert archive / California / Flash Flood Warnings in 2017
Flash Flood Warning 59, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flash flood warning at Feb 20, 2017, 10:13 AM PST for San Benito County, Santa Clara County, California. It was in force for 6 hr. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Feb 20, 2017, 10:13 AM PST (18:13 UTC)
- Expired
- Feb 20, 2017, 4:00 PM PST
- In force
- 6 hr
- Issued by
- NWS San Francisco Bay Area, CA
- Area
- Storm-based polygon
- Flood severity
- None
Counties San Benito County, CA, Santa Clara County, CA
The radar
The San Francisco radar (KMUX), 50 km from the middle of the area, began a volume at 18:15 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Feb 20, 12:12 PM PST | FLOOD | 9 N Hollister, CA | ROADWAY FLOODING SR 152 AT CASA DE FRUTA |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Oakland, CA (KOAK), launched 12:00Z, 6.2 hours before the alert went out and 109 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
- 515 m above ground
- 0-6 km bulk shear
- 75 kt
- 0-1 km storm-relative helicity
- 364 m²/s²
- 0-3 km storm-relative helicity
- 367 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
431
WGUS56 KMTR 201813
FFWMTR
CAC069-085-210000-
/O.NEW.KMTR.FF.W.0059.170220T1813Z-170221T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
1013 AM PST MON FEB 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...
Northwestern San Benito County in central California...
* Until 400 PM PST
* At 1007 AM PST, stream gage reports indicated rapidly rising water
levels on Pacheco Creek near Dunneville. Current water levels are
at 8.09 feet. Because of prior levee breaches, flooding begins
around 10 feet. The previously established flood stage is 12
feet. Streamflow forecasting suggests water levels may reach 19.2
feet by tonight around 10pm local time. Ponding of water on the
floodplain may already be occurring.
* Some locations that will experience flooding include...
Lovers Lane, Frazier Lake, Soap/San Felipe Lake, and lower Pacheco
Creek north of Hollister.
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 3711 12127 3683 12127 3692 12152 3701 12150
3701 12139 3710 12131
$$
MWSThe office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 20, 3:53 AM PST | River Flood Warning | MTR | Santa Clara | 59 hr |
| Feb 20, 4:23 AM PST | Flash Flood Warning | MTR | Monterey | 3 hr |
| Feb 20, 5:03 AM PST | River Flood Warning | MTR | Monterey | 29 hr |
| Feb 20, 7:07 AM PST | Flash Flood Warning | MTR | Monterey | 6 hr |
| Feb 20, 7:35 AM PST | Areal Flood Advisory | MTR | Marin, Napa, City and County of San Francisco, San Mateo, Sonoma | 3 hr |
| Feb 20, 7:40 AM PST | Flash Flood Warning | MTR | Santa Cruz | 6 hr |
| Feb 20, 7:44 AM PST | Areal Flood Advisory | MTR | San Mateo, Santa Clara, Santa Cruz | 3 hr |
| Feb 20, 8:14 AM PST | Flash Flood Warning | MTR | Marin, Sonoma | 4 hr |
| Feb 20, 8:22 AM PST | Areal Flood Warning | MTR | Sonoma | 60 hr |
| Feb 20, 8:56 AM PST | Flash Flood Warning | MTR | San Benito | 6 hr |
| Feb 20, 9:04 AM PST | Flash Flood Warning | MTR | Santa Cruz | 6 hr |
| Feb 20, 10:26 AM PST | Flash Flood Warning | MTR | Alameda | 6 hr |
| Feb 20, 10:34 AM PST | Areal Flood Advisory | MTR | Marin, Napa, City and County of San Francisco, San Mateo, Sonoma | 3 hr |
| Feb 20, 10:48 AM PST | Areal Flood Advisory | MTR | San Mateo, Santa Clara, Santa Cruz | 3 hr |
| Feb 20, 11:21 AM PST | Areal Flood Advisory | MTR | Alameda, Contra Costa, Santa Clara | 3 hr |
| Feb 20, 1:32 PM PST | Areal Flood Advisory | MTR | Marin, Napa, City and County of San Francisco, San Mateo, Sonoma | 3 hr |
| Feb 20, 1:48 PM PST | Areal Flood Advisory | MTR | San Mateo, Santa Clara, Santa Cruz | 3 hr |
| Feb 20, 2:14 PM PST | Areal Flood Advisory | MTR | Monterey | 4 hr |
| Feb 20, 2:24 PM PST | Small Craft Advisory | MTR | 18 hr | |
| Feb 20, 2:40 PM PST | Areal Flood Advisory | MTR | San Mateo | 65 min |
| Feb 20, 3:23 PM PST | Areal Flood Warning | MTR | Santa Clara | 6 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.