Alert archive / California / Flash Flood Warnings in 2003

Flash Flood Warning 1, NWS San Francisco Bay Area, CA

December 29, 2003Napa County, California

NWS San Francisco Bay Area, CA issued this flash flood warning at Dec 29, 2003, 11:06 AM PST for Napa County, California. It was in force for 54 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Dec 29, 2003, 11:06 AM PST (19:06 UTC)
Expired
Dec 29, 2003, 12:00 PM PST
In force
54 min
Issued by
NWS San Francisco Bay Area, CA
Area
Whole counties

County Napa County, CA

The radar

The Sacramento radar (KDAX), 57 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.

The nearest sounding before it

Oakland, CA (KOAK), launched 12:00Z, 7.1 hours before the alert went out and 87 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 2003-12-29Temperature 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 2003-12-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 315 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
630 m above ground
0-6 km bulk shear
67 kt
0-1 km storm-relative helicity
315 m²/s²
0-3 km storm-relative helicity
564 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
WGUS56 KMTR 291918
FFWMTR
CAC055-292000-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1106 AM PST MON DEC 29 2003

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

* FLASH FLOOD WARNING FOR...
  CENTRAL NAPA COUNTY IN CALIFORNIA
  THIS INCLUDES THE CITY OF NAPA

* UNTIL NOON PST

* AT 1059 AM PST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED  
A BAND OF HEAVY RAIN MOVING INTO CENTRAL NAPA COUNTY. RAIN RATES OF 
ONE-HALF INCH PER HOUR WILL FALL ON ALREADY SATURATED GROUND. OF 
PARTICULAR CONCERN IS NAPA CREEK WHICH FLOWS INTO THE CITY OF NAPA.

RUNOFF FROM THIS HEAVY RAIN WILL CAUSE FLASH FLOODING OF NAPA CREEK 
AND SMALLER CREEKS AND STREAMS IN THE AREA. ROADS AND ROADSIDE 
CULVERTS WILL ALSO BECOME FLOODED. THE HEAVY RAINS COULD ALSO TRIGGER ROCK 
AND MUDSLIDES IN STEEP TERRAIN.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. 
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY. 
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE 
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS 
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY 
AUTOMOBILE. IF YOUR VEHICLE STALLS, ABANDON IT IMMEDIATELY AND SEEK 
HIGHER GROUND.

TO REPORT SEVERE WEATHER HAVE THE NEAREST LAW ENFORCEMENT AGENCY
RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE OFFICE IN SAN
FRANCISCO BAY AREA.

$$

Nearby

Flash Flood Warnings in California, 2003Every flash flood warning in 2003

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.