Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 3, NWS San Francisco Bay Area, CA

November 30, 2012Monterey County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Nov 30, 2012, 9:29 AM PST for Monterey County, California. It was in force for 61 min. 3 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
Nov 30, 2012, 9:29 AM PST (17:29 UTC)
Expired
Nov 30, 2012, 10:30 AM PST
In force
61 min
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), 110 km from the middle of the area, began a volume at 17:30 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
Nov 30, 9:31 AM PSTHEAVY RAIN 3.352 Ne Julia Pfeiffer Bur, CASTORM TOTAL MEASURED AT 3368 FEET
Nov 30, 9:31 AM PSTHEAVY RAIN 4.855 Nnw Lucia, CASTORM TOTAL MEASURED AT 3288 FEET ELEVATION
Nov 30, 10:25 AM PSTFLASH FLOOD6 Nw Pico Blanco Campgr, CACOCORAHS SPOTTER REOPRTS 3.50 INCHES OF RAIN SINCE 7 AM THIS MORNING AND A STORM TOTAL OF 4.88 INCHES. DRAINAGE CULVERTS OVERWHELMED AND BACKING UP WITH SERIOUS EROSION BEING REPORTED.

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, 5.5 hours before the alert went out and 178 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 2012-11-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 60 joules per kilogram.LCLLFCEL10008507005003002001001 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 2012-11-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 462 square meters per square second.1939587897117Sfc1 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
60 J/kg
Mixed-layer CIN
-60 J/kg
Mixed-layer LCL
551 m above ground
0-6 km bulk shear
67 kt
0-1 km storm-relative helicity
462 m²/s²
0-3 km storm-relative helicity
616 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS56 KMTR 301729
FFWMTR
CAC053-301830-
/O.NEW.KMTR.FF.W.0003.121130T1729Z-121130T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
929 AM PST FRI NOV 30 2012

THE NATIONAL WEATHER SERVICE IN THE SAN FRANCISCO BAY AREA HAS
ISSUED A

* FLASH FLOOD WARNING FOR...
  MONTEREY COUNTY IN WESTERN CALIFORNIA...
  THIS INCLUDES THE CITIES OF...TASSAJARA HOT SPRINGS...JAMESBURG...
  BIG SUR VILLAGE...

* UNTIL 1030 AM PST.

* AT 925 AM PST...NWS DOPPLER RADAR AND AUTOMATED RAIN GAGES   
INDICATED HEAVY RAINFALL TOTALS IN THE HIGH TERRAIN OF MONTEREY 
COUNTY. RAINFALL OF 2 TO 4 INCHES HAS ALREADY FALLEN AND HOURLY 
RATES OF 1 INCH PER HOUR WILL CONTINUE THROUGH 1030 AM. 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO PICO BLANCO
  CAMPGROUND AND ANDREW MOLERA STATE PARK

A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.

RUNOFF FROM HEAVY RAINFALL WILL CAUSE LOCALIZED FLOODING OF SMALL
CREEKS AND STREAMS AS WELL AS ROADWAYS...UNDERPASSES AND OTHER LOW
LYING SPOTS. DO NOT ATTEMPT TO CROSS SWIFTLY FLOWING WATER OR WATER
OF UNKNOWN DEPTH. TURN AROUND...DONT DROWN.

IT IS IMPORTANT FOR CAMPERS AND HIKERS TO KNOW WHERE THEY ARE
RELATIVE TO CREEKS...STREAMS...OR RIVERS WHICH CAN BECOME DANGEROUS
IN HEAVY RAINS. BE PARTICULARLY AWARE IN HILLY TERRAIN WHERE MANY LOW
WATER CROSSINGS CAN QUICKLY BECOME KILLERS.

IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE UP TO HIGHER GROUND 
TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING 
WHEN WATER BEGINS RISING.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE.

LAT...LON 3614 12167 3620 12175 3623 12182 3632 12191
      3636 12192 3648 12184 3629 12155 3603 12138
      3602 12151 3601 12151 3601 12158

$$

JOHNSON
1 follow-up statement
027 
WGUS76 KMTR 301825
FFSMTR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1025 AM PST FRI NOV 30 2012

CAC053-301835-
/O.EXP.KMTR.FF.W.0003.000000T0000Z-121130T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTEREY CA-
1025 AM PST FRI NOV 30 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 1030 AM PST FOR MONTEREY
COUNTY...

HEAVY RAIN HAS ENDED FOR THE TIME BEING ACROSS THE AREA OF CONCERN. 
ADDITIONAL RAINFALL WILL CONTINUE AND AN URBAN AND SMALL STREAM 
FLOOD ADVISORY REMAINS IN EFFECT FOR THE AREA.

LAT...LON 3614 12167 3620 12175 3623 12182 3632 12191
      3636 12192 3648 12184 3629 12155 3603 12138
      3602 12151 3601 12151 3601 12158

$$

JOHNSON

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 30, 4:16 AM PSTFlash Flood WarningMTRSonoma119 min
Nov 30, 5:38 AM PSTAreal Flood AdvisoryMTRSanta Cruz6 hr
Nov 30, 6:22 AM PSTFlash Flood WarningMTRSonoma3 hr
Nov 30, 8:27 AM PSTAreal Flood AdvisoryMTRAlameda, Contra Costa, Marin, Monterey, San Benito, City and County of San Francisco and 3 more3 hr
Nov 30, 9:02 AM PSTAreal Flood AdvisoryMTRMarin, Napa, Sonoma118 min
Nov 30, 10:38 AM PSTFlash Flood WarningMTRMonterey82 min
Nov 30, 11:03 AM PSTRiver Flood WatchMTRSonoma26 days
Nov 30, 11:25 AM PSTAreal Flood AdvisoryMTRAlameda, Contra Costa, Marin, Monterey, San Benito, City and County of San Francisco and 3 more3 hr
Nov 30, 11:59 AM PSTFlash Flood WarningMTRMonterey3 hr
Nov 30, 2:56 PM PSTSmall Craft AdvisoryMTR47 hr

Nearby

Flash Flood Warnings in California, 2012Every flash flood warning in 2012

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.