Alert archive / California / Areal Flood Warnings in 2012

Areal Flood Warning 3, NWS Sacramento, CA

December 2, 2012Shasta County, Tehama County, California

NWS Sacramento, CA issued this areal flood warning at Dec 2, 2012, 4:23 AM PST for Shasta County, Tehama 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 counties it named.

The facts

Issued
Dec 2, 2012, 4:23 AM PST (12:23 UTC)
Expired
Dec 2, 2012, 10:06 AM PST
In force
6 hr
Issued by
NWS Sacramento, CA
Area
Storm-based polygon
Flood severity
None

Counties Shasta County, CA, Tehama County, CA

The radar

The Beale AFB radar (KBBX), 114 km from the middle of the area, began a volume at 12:24 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

Medford/Jackson, OR (KMFR), launched 12:00Z, 0.4 hours before the alert went out and 221 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, Medford/Jackson, OR at 12:00Z on 2012-12-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 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, Medford/Jackson, OR at 12:00Z on 2012-12-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 65 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
8 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
838 m above ground
0-6 km bulk shear
85 kt
0-1 km storm-relative helicity
65 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Sacramento, CA wrote its last area forecast discussion before this areal flood warning went out at Dec 1, 10:58 PM PST, 5 hours 25 minutes earlier.

Area forecast discussion, Dec 1, 10:58 PM PST, 5 hours 25 minutes before
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Hazardous weather outlook, Dec 1, 7:00 AM PST, 21 hours 23 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SACRAMENTO CA
700 AM PST SAT DEC 1 2012

CAZ013>019-063-064-066>069-021500-
SHASTA LAKE AREA/NORTHERN SHASTA COUNTY-
BURNEY BASIN/EASTERN SHASTA COUNTY-NORTHERN SACRAMENTO VALLEY-
CENTRAL SACRAMENTO VALLEY-SOUTHERN SACRAMENTO VALLEY-
CARQUINEZ STRAIT AND DELTA-NORTHERN SAN JOAQUIN VALLEY-
MOUNTAINS SOUTHWESTERN SHASTA TO NORTHERN LAKE COUNTIES-
CLEAR LAKE/SOUTHERN LAKE COUNTY-MOTHERLODE-
EAST FOOTHILLS/NORTH SACRAMENTO VALLEY-
WESTERN PLUMAS COUNTY/LASSEN PARK-WEST SLOPE NORTHERN SIERRA NEVADA-
700 AM PST SAT DEC 1 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR INTERIOR NORTHERN CALIFORNIA.

.DAY ONE...TODAY

A POWERFUL FRONTAL SYSTEM IS EXPECTED TO MOVE INTO NORTHERN
CALIFORNIA LATE THIS AFTERNOON AND NIGHT. THIS SYSTEM WILL BRING
PERIODS OF HEAVY RAIN AND STRONG WINDS THROUGH SUNDAY AFTERNOON.

* FLOOD WATCH................SEE WGUS66 KSTO - FFASTO FOR DETAILS *

* WIND ADVISORY..............SEE WWUS76 KSTO - NPWSTO FOR DETAILS *

.DAYS TWO THROUGH SEVEN... SUNDAY THROUGH FRIDAY

THE STRONG FRONTAL SYSTEM SHOULD BE EXITING NORTHERN CALIFORNIA BY
SUNDAY AFTERNOON. RAINFALL SHOULD DECREASE BY AFTERNOON WITH LIGHTER
WINDS. WITH LOWERING SNOW LEVELS SUNDAY AFTERNOON...SIERRA CASCADE
PASS LEVELS MAY START TO PICK UP SOME SNOWFALL. A FEW TO SEVERAL
INCHES OF SNOWFALL WILL BE POSSIBLE AT PASS LEVELS SUNDAY EVENING
BEFORE THE PRECIPITATION ENDS.

* FLOOD WATCH................SEE WGUS66 KSTO - FFASTO FOR DETAILS *

* WIND ADVISORY..............SEE WWUS76 KSTO - NPWSTO FOR DETAILS *

* SPECIAL WEATHER STATEMENT..SEE WWUS86 KSTO - SPSSTO FOR DETAILS *

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS TO THEIR LOCAL NATIONAL WEATHER SERVICE OFFICE.

THE LATEST WEATHER INFORMATION IS AVAILABLE ON THE INTERNET AT
(LOWER CASE): HTTP://WWW.WRH.NOAA.GOV/STO

The office that day

Everything else NWS Sacramento, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 1, 5:39 PM PSTSpecial Weather StatementSTOSutter51 min
Dec 1, 10:38 PM PSTAreal Flood AdvisorySTOButte, Colusa, Glenn, Lake, Lassen, Nevada and 8 more12 hr
Dec 1, 10:46 PM PSTAreal Flood AdvisorySTOButte, Colusa, Glenn, Lake, Lassen, Nevada and 8 more12 hr
Dec 2, 6:22 AM PSTAreal Flood AdvisorySTOAlpine, Amador, Calaveras, El Dorado, Lake, Nevada and 9 more25 hr
Dec 2, 6:46 AM PSTFlood WatchSTO4 hr
Dec 2, 9:06 AM PSTRiver Flood WarningSTOTehama18 hr
Dec 2, 10:01 AM PSTAreal Flood WarningSTOButte, Colusa, Glenn, Lake, Nevada, Placer and 7 more21 hr

Nearby

Areal Flood Warnings in California, 2012Every areal 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.