Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 5, NWS San Francisco Bay Area, CA

January 4, 2017Santa Clara County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 4, 2017, 3:30 PM PST for Santa Clara County, California. It was in force for 2 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, 3:30 PM PST (23:30 UTC)
Expired
Jan 4, 2017, 5:30 PM PST
In force
2 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), 35 km from the middle of the area, began a volume at 23:32 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, 11.5 hours before the alert went out and 100 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.

Skew-T log-pSkew-T log-p diagram, Oakland, CA at 12:00Z on 2017-01-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Oakland, CA at 12:00Z on 2017-01-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 166 square meters per square second.1939587897117136Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
3 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
513 m above ground
0-6 km bulk shear
74 kt
0-1 km storm-relative helicity
166 m²/s²
0-3 km storm-relative helicity
200 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

045 
WGUS56 KMTR 042330
FFWMTR
CAC085-050130-
/O.NEW.KMTR.FF.W.0005.170104T2330Z-170105T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
330 PM PST WED JAN 4 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 530 PM PST

* At 328 PM PST, the public media reported flash flooding of Uvas
  Creek overflowing near Christmas Hill Park. Flash flooding is
  already occurring.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 3696 12156 3699 12160 3701 12158 3698 12154

$$

WP
1 follow-up statement
852 
WGUS76 KMTR 050127
FFSMTR

Flash Flood Statement
National Weather Service San Francisco CA
527 PM PST WED JAN 4 2017

CAC085-050130-
/O.EXP.KMTR.FF.W.0005.000000T0000Z-170105T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Santa Clara CA-
527 PM PST WED JAN 4 2017

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN SANTA CLARA COUNTY WILL
EXPIRE AT 530 PM PST...

The flash flood warning will be allowed to expire. However due to
periodic releases of water from Uvas Reservoir...flooding of Uvas
Creek near Christmas Hill Park is still likely to continue. Road
closures are in place at the impacted area. Please continue to heed
any road closures.

LAT...LON 3696 12156 3699 12160 3701 12158 3698 12154

$$

WP

The office that day

Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 3, 5:31 PM PSTAreal Flood WarningMTRAlameda, Contra Costa, Marin, Monterey, Napa, San Benito and 5 more6 hr
Jan 3, 5:43 PM PSTAreal Flood AdvisoryMTRAlameda, Contra Costa, Marin, Monterey, Napa, San Benito and 5 more12 hr
Jan 4, 1:08 AM PSTFlash Flood WarningMTRSanta Cruz3 hr
Jan 4, 2:35 AM PSTSmall Craft AdvisoryMTR6 hr
Jan 4, 3:41 AM PSTFlash Flood WarningMTRSonoma4 hr
Jan 4, 3:53 AM PSTFlash Flood WarningMTRSanta Cruz3 hr
Jan 4, 4:40 AM PSTFlash Flood WarningMTRMonterey6 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.