Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 10, 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, 11:11 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, 11:11 AM PST (19:11 UTC)
Expired
Jan 8, 2017, 4:45 PM 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), 80 km from the middle of the area, began a volume at 19:10 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, 11:18 AM PSTFLOODSanta Rosa, CAROADWAY FLOODING REPORTED AT SKILLMAN LANE AND THOMPSON LANE. APPROXIMATELY 6 INCHES OF WATER ACROSS THE ROADWAY.
Jan 8, 11:40 AM PSTFLOODGraton, CADOWNED TREES AND FLOODED ROADWAYS JUST WEST OF GRATON.

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, 7.2 hours before the alert went out and 71 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.

306 
WGUS56 KMTR 081911
FFWMTR
CAC097-082145-
/O.NEW.KMTR.FF.W.0010.170108T1911Z-170108T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
1111 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 145 PM PST

* At 1110 AM PST, Doppler radar indicated additional rainfall moving
  across the warned area. At this time the most significant flooding
  is expected south and southeast of the city of Santa Rosa.

LAT...LON 3840 12250 3816 12239 3816 12241 3815 12238
      3814 12238 3814 12242 3832 12259 3832 12271
      3836 12285 3850 12287 3853 12271

$$

Bell
2 follow-up statements
988 
WGUS56 KMTR 082139
FFWMTR
CAC097-090045-
/O.EXT.KMTR.FF.W.0010.000000T0000Z-170109T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in The San Francisco Bay Area has
extended the

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

* Until 445 PM PST

* At 136 PM PST, although most of the heavy rainfall has ended in
  the North Bay many local streams and creeks are currently above
  flood stage and will take several hours to recede.

LAT...LON 3840 12250 3816 12239 3816 12241 3815 12238
      3814 12238 3814 12242 3832 12259 3832 12271
      3836 12285 3850 12287 3853 12271

$$

bell
175 
WGUS76 KMTR 090042
FFSMTR

Flash Flood Statement
National Weather Service San Francisco CA
442 PM PST SUN JAN 8 2017

CAC097-090051-
/O.EXP.KMTR.FF.W.0010.000000T0000Z-170109T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Sonoma CA-
442 PM PST SUN JAN 8 2017

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN SONOMA COUNTY WILL EXPIRE
AT 445 PM PST...

The heavy rain has ended across Sonoma County. Additional flooding
is no longer expected. Please continue to heed any remaining
roadclosures.

LAT...LON 3840 12250 3816 12239 3816 12241 3815 12238
      3814 12238 3814 12242 3832 12259 3832 12271
      3836 12285 3850 12287 3853 12271

$$

BFG

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, 4:23 AM PSTFlash Flood WarningMTRSonoma6 hr
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, 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.