Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 31, NWS San Francisco Bay Area, CA

January 22, 2017Napa County, Sonoma County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 22, 2017, 5:11 AM PST for Napa County, Sonoma County, California. It was in force for 4 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 22, 2017, 5:11 AM PST (13:11 UTC)
Expired
Jan 22, 2017, 9:15 AM PST
In force
4 hr
Issued by
NWS San Francisco Bay Area, CA
Area
Storm-based polygon
Flood severity
None

Counties Napa County, CA, Sonoma County, CA

The radar

The Sacramento radar (KDAX), 73 km from the middle of the area, began a volume at 13:15 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.

The nearest sounding before it

Oakland, CA (KOAK), launched 12:00Z, 1.2 hours before the alert went out and 57 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 2017-01-22Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Oakland, CA at 12:00Z on 2017-01-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 706 square meters per square second.1939587897117136156Sfc1 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
760 m above ground
0-6 km bulk shear
101 kt
0-1 km storm-relative helicity
706 m²/s²
0-3 km storm-relative helicity
1006 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

287 
WGUS56 KMTR 221311
FFWMTR
CAC055-097-221715-
/O.NEW.KMTR.FF.W.0031.170122T1311Z-170122T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
511 AM PST SUN JAN 22 2017

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

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

* Until 915 AM PST

* At 509 AM PST, gauge reports indicated heavy rain falling across
  the warned area, as well as stage rapidly rising above flood
  levels on Sonoma Creek at Agua Caliente. Flash flooding is already
  occurring.

* Some locations that will experience flooding include...
  the lower Sonoma Valley area.

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 3816 12239 3815 12240 3816 12240 3814 12242
      3833 12253 3836 12249

$$

MWS

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 22, 12:45 AM PSTAreal Flood WarningMTRMonterey6 hr
Jan 22, 1:47 AM PSTAreal Flood WarningMTRSonoma6 hr
Jan 22, 2:47 AM PSTHigh Surf AdvisoryMTRMarin, Monterey, City and County of San Francisco, San Mateo, Santa Cruz, Sonoma48 hr
Jan 22, 4:30 AM PSTAreal Flood AdvisoryMTRSan Mateo60 min
Jan 22, 5:47 AM PSTAreal Flood AdvisoryMTRAlameda, Santa Clara, Santa Cruz118 min
Jan 22, 6:28 AM PSTFlash Flood WarningMTRSanta Cruz4 hr
Jan 22, 7:32 AM PSTAreal Flood WarningMTRSonoma24 hr
Jan 22, 8:08 AM PSTFlash Flood WarningMTRMonterey3 hr
Jan 22, 8:12 AM PSTFlash Flood WarningMTRSanta Clara3 hr
Jan 22, 8:35 AM PSTFlash Flood WarningMTRSanta Cruz3 hr
Jan 22, 11:34 AM PSTAreal Flood WarningMTRSanta Cruz24 hr
Jan 22, 12:27 PM PSTAreal Flood AdvisoryMTRSan Mateo, Santa Clara, Santa Cruz6 hr
Jan 22, 12:35 PM PSTFlash Flood WarningMTRSan Benito, Santa Clara6 hr
Jan 22, 1:17 PM PSTSpecial Marine WarningMTR28 min
Jan 22, 2:29 PM PSTSpecial Weather StatementMTRSan Mateo16 min

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.