Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 4, NWS San Francisco Bay Area, CA

January 4, 2017Monterey County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 4, 2017, 4:40 AM PST for Monterey County, California. It was in force for 6 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, 4:40 AM PST (12:40 UTC)
Expired
Jan 4, 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 Monterey County, CA

The radar

The San Francisco radar (KMUX), 91 km from the middle of the area, began a volume at 12:41 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, 0.7 hours before the alert went out and 160 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.

802 
WGUS56 KMTR 041240
FFWMTR
CAC053-041830-
/O.NEW.KMTR.FF.W.0004.170104T1240Z-170104T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Francisco CA
440 AM PST WED JAN 4 2017

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

* Flash Flood Warning for the Soberanes Burn Area in...
  West central Monterey County in central California...

* Until 1030 AM PST
    
* At 433 AM PST, Doppler radar and automated rain gauges indicated
  that heavy rain was falling over the area.  Rain gages above Big
  Sur, Partington, and the Palo Colorado areas indicate locally
  heavy rainfall exceeding 0.75 inches per hour and in some cases
  reaching 1.50 inches per hour.  The latter far exceeds threshold
  criteria for debris flows on the Soberanes Burn Scar.

  This is a life threatening situation. Anyone living or traveling  
  on roads in the Soberanes Fire burn area or along secondary roads 
  and fire breaks should be alert for probable road problems due to
  erosion...debris flows...rockfalls and debris.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a dangerous situation.  If you observe movement of soils...
debris...or large amounts of water you should move to higher ground
immediately. Residents need to be alert for the potential of mud and
debris flows. A debris flow of only a few inches deep can be
powerful enough to move vehicle off the road.

If you are in or near the warned area, you should seek a safe
location immediately. Your life may depend on how quickly you react.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 3652 12190 3644 12175 3645 12171 3628 12144
      3625 12149 3625 12158 3618 12148 3614 12159
      3631 12190 3649 12195

$$

MWS
1 follow-up statement
845 
WGUS76 KMTR 041822
FFSMTR

Flash Flood Statement
National Weather Service San Francisco CA
1022 AM PST WED JAN 4 2017

CAC053-041831-
/O.EXP.KMTR.FF.W.0004.000000T0000Z-170104T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monterey CA-
1022 AM PST WED JAN 4 2017

...THE FLASH FLOOD WARNING FOR Soberanes Burn Area WEST CENTRAL
MONTEREY COUNTY WILL EXPIRE AT 1030 AM PST...

Flood waters have receded, and are no longer expected to pose a
threat to life or property over the Soberanes Burn Area. Please
continue to heed any road closures and never drive into flooded
roadways.

LAT...LON 3652 12190 3644 12175 3645 12171 3628 12144
      3625 12149 3625 12158 3618 12148 3614 12159
      3631 12190 3649 12195

$$

RGASS

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, 3:30 PM PSTFlash Flood WarningMTRSanta Clara2 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.