Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 7, NWS San Francisco Bay Area, CA

January 8, 2017Sonoma County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 8, 2017, 4:23 AM PST for Sonoma County, California. It was in force for 6 hr. 2 reports 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
Jan 8, 2017, 4:23 AM PST (12:23 UTC)
Expired
Jan 8, 2017, 10:30 AM PST
In force
6 hr
Issued by
NWS San Francisco Bay Area, CA
Area
Storm-based polygon
Flood severity
None

County Sonoma County, CA

The radar

The Sacramento radar (KDAX), 87 km from the middle of the area, began a volume at 12:25 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

TimeReportWhereRemark
Jan 8, 8:06 AM PSTFLOODPetaluma, CASTONY POINT RD CLOSED BETWEEN PEPPER AND RAINSVILLE IN PETALUMA DUE TO FLOODING.
Jan 8, 8:32 AM PSTFLOODPetaluma, CAADOBE ROAD AT PETALUMA HILL RD IN PENNGROVE FLOODED, NOT PASSABLE.

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, 0.4 hours before the alert went out and 69 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 2017-01-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Oakland, CA at 12:00Z on 2017-01-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 463 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
607 m above ground
0-6 km bulk shear
65 kt
0-1 km storm-relative helicity
463 m²/s²
0-3 km storm-relative helicity
874 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

516 
WGUS56 KMTR 081223
FFWMTR
CAC097-081830-
/O.NEW.KMTR.FF.W.0007.170108T1223Z-170108T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
423 AM PST SUN JAN 8 2017

The National Weather Service in The San Francisco Bay Area has issued
a

* Flash Flood Warning for...
  Southeastern Sonoma County in northern California...

* Until 1030 AM PST Sunday

* At 419 AM PST, automated stream gages in the Penngrove area near
  Petaluma indicated rises in local creek levels above major flood
  stage. Heavy rain is expected across the warned area through the
  morning hours.

* Some locations that will experience flooding include...
  Penngrove and Petaluma.

LAT...LON 3833 12257 3811 12249 3820 12257 3822 12270
      3826 12273 3830 12271

$$

MWS

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 7, 9:12 PM PSTRiver Flood WarningMTRSanta Clara25 hr
Jan 7, 9:12 PM PSTRiver Flood WarningMTRNapa35 hr
Jan 7, 11:23 PM PSTSpecial Marine WarningMTR52 min
Jan 7, 11:35 PM PSTRiver Flood WarningMTRMonterey24 hr
Jan 8, 12:16 AM PSTFlash Flood WarningMTRSanta Clara6 hr
Jan 8, 12:25 AM PSTSpecial Marine WarningMTR35 min
Jan 8, 12:49 AM PSTSpecial Weather StatementMTRSanta Cruz26 min
Jan 8, 1:05 AM PSTAreal Flood AdvisoryMTRMonterey, San Benito3 hr
Jan 8, 1:49 AM PSTAreal Flood AdvisoryMTRContra Costa, Marin, Napa, City and County of San Francisco, San Mateo, Sonoma3 hr
Jan 8, 2:26 AM PSTSmall Craft AdvisoryMTR24 hr
Jan 8, 3:26 AM PSTRiver Flood WarningMTRNapa32 hr
Jan 8, 3:26 AM PSTRiver Flood WarningMTRSonoma5 days
Jan 8, 5:25 AM PSTFlash Flood WarningMTRSonoma6 hr
Jan 8, 6:39 AM PSTAreal Flood AdvisoryMTRMarin, Napa, Sonoma3 hr
Jan 8, 9:58 AM PSTAreal Flood AdvisoryMTRMarin, Napa, Sonoma2 hr
Jan 8, 10:49 AM PSTFlash Flood WarningMTRSonoma6 hr
Jan 8, 11:11 AM PSTFlash Flood WarningMTRSonoma6 hr
Jan 8, 12:30 PM PSTAreal Flood AdvisoryMTRMarin, Napa, Sonoma3 hr
Jan 8, 12:45 PM PSTAreal Flood AdvisoryMTRSanta Cruz4 hr
Jan 8, 12:45 PM PSTAreal Flood AdvisoryMTRSanta Clara4 hr
Jan 8, 1:44 PM PSTFlash Flood WarningMTRMonterey4 hr
Jan 8, 1:58 PM PSTFlash Flood WarningMTRSanta Cruz3 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.