Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 12, NWS San Francisco Bay Area, CA

January 8, 2017Santa Cruz County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Jan 8, 2017, 1:58 PM PST for Santa Cruz County, California. It was in force for 3 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 8, 2017, 1:58 PM PST (21:58 UTC)
Expired
Jan 8, 2017, 5:00 PM PST
In force
3 hr
Issued by
NWS San Francisco Bay Area, CA
Area
Storm-based polygon
Flood severity
None

County Santa Cruz County, CA

The radar

The San Francisco radar (KMUX), 20 km from the middle of the area, began a volume at 21:57 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, 10.0 hours before the alert went out and 80 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°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.

730 
WGUS56 KMTR 082158
FFWMTR
CAC087-090100-
/O.NEW.KMTR.FF.W.0012.170108T2158Z-170109T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

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

* Flash Flood Warning for...
  Central Santa Cruz County in northern California...

* Until 500 PM PST

* At 156 PM PST, Doppler radar and automated rain gauges indicated
  heavy rain falling across the warned area. Flash flooding is
  expected to begin shortly.

Flood waters are moving down the San Lorenzo River from Big Trees
toward Paradise Park. The flood crest is expected to reach
near 20 feet between 3 and 4 pm.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

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 3705 12205 3698 12201 3697 12204 3704 12208

$$

BFG
2 follow-up statements
760 
WGUS76 KMTR 090027
FFSMTR

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

CAC087-090100-
/O.CON.KMTR.FF.W.0012.000000T0000Z-170109T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Santa Cruz CA-
427 PM PST SUN JAN 8 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 PM PST FOR
CENTRAL SANTA CRUZ COUNTY...

At 425 PM PST, gauge reports indicated heavy rain was falling over
the warned area.  Flash flooding is expected to begin shortly.

Flood waters are moving down the San Lorenzo River from Big Trees
toward Paradise Park. The flood crest is expected to reach near 18
feet between 5 and 7 pm.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

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 3705 12205 3698 12201 3697 12204 3704 12208

$$

BFG
615 
WGUS76 KMTR 090054
FFSMTR

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

CAC087-090102-
/O.EXP.KMTR.FF.W.0012.000000T0000Z-170109T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Santa Cruz CA-
454 PM PST SUN JAN 8 2017

...THE FLASH FLOOD WARNING FOR CENTRAL SANTA CRUZ COUNTY WILL EXPIRE
AT 500 PM PST...

The heavy rain has ended over the Santa Cruz Mountains. Flood waters
are expected to recede over the next few hours in the San Lorenzo
River. Please continue to heed any remaining road closures.

LAT...LON 3705 12205 3698 12201 3697 12204 3704 12208

$$

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, 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

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.