Alert archive / California / Colusa County

Weather alerts in Colusa County, California, 2011

10 weather alerts in 2011, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Colusa County and its neighbors

Each county as a circle sized by its count in 2011. Tap one for its archive.

Alerts
10
Warnings
4
Watches
0
Advisories
4
Busiest month
March9 alerts
Busiest day
March 21, 20114 alerts

Over time

By month

Warning verification

How often warnings here had a storm report inside them, and how much warning the reports had.

1 of 2 tornado warnings covering Colusa County in 2011 had a tornado report inside them; 1 of 3 tornado reports fell inside a warning, on average 2 minutes after it went out.

Colusa County, 2011

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings2150%333%2 min
Severe thunderstorm warnings2150%1100%11 min
Flash flood warnings00

Each office's whole area, 2011

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Sacramento, CA: tornado warnings10460%1644%19 min
NWS Sacramento, CA: severe thunderstorm warnings18383%757%19 min

An office's figures cover every county it serves, including across state lines.

Verified by the Iowa Environmental Mesonet's Cow, which matches each storm-based warning with the local storm reports inside its polygon while it was in force, within 15 km of its edge: a tornado warning counts as verified on a tornado report, a severe thunderstorm warning on hail of 1 inch or more, a gust of 58 mph or more, or wind damage, a flash flood warning on a flash flood report. The false alarm ratio is the share of warnings with no such report; "inside a warning" is the probability of detection, the share of reports that fell inside one; lead time runs from the warning's issue to each report inside it, counting zero for a report that came first. A warning with no report is not proof nothing happened: reports come from spotters, the public and damage surveys, and are thin where few people live.

The alerts

Every alert, in the order issued. Times are local, Pacific Time. Each opens its own page with the text, the map, the radar and the sounding.

IssuedProductOfficeLasted
Mar 15, 7:56 PM PDTAreal Flood AdvisorySTO6 hr
Mar 18, 11:25 AM PDTAreal Flood AdvisorySTO19 hr
Mar 20, 12:16 AM PDTAreal Flood AdvisorySTO18 hr
Mar 21, 2:27 PM PDTSpecial Weather StatementSTO33 min
Mar 21, 2:59 PM PDTSevere Thunderstorm WarningSTO61 min
Mar 21, 3:05 PM PDTTornado WarningSTO40 min
Mar 21, 3:48 PM PDTTornado WarningSTO27 min
Mar 23, 5:08 PM PDTSevere Thunderstorm WarningSTO52 min
Mar 24, 7:57 AM PDTAreal Flood AdvisorySTO30 hr
Jun 1, 4:48 PM PDTSpecial Weather StatementSTO57 min

By product

Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20102012

Sources

National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.