Alert archive / California / Tehama County

Weather alerts in Tehama County, California, 2009

19 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Tehama County and its neighbors

Each county as a circle sized by its count in 2009. Tap one for its archive.

Alerts
19
Warnings
12
Watches
0
Advisories
1
Busiest month
March6 alerts
Busiest day
March 4, 20094 alerts

Over time

By month

Warning verification

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

Tehama County, 2009

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings110100%10%
Flash flood warnings10100%0

Each office's whole area, 2009

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Sacramento, CA: tornado warnings010%
NWS Sacramento, CA: severe thunderstorm warnings310100%30%
NWS Sacramento, CA: flash flood warnings3167%250%46 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
Jan 24, 5:05 PM PSTSevere Thunderstorm WarningSTO25 min
Mar 2, 9:45 AM PSTFlash Flood WarningSTO12 hr
Mar 3, 5:34 PM PSTSevere Thunderstorm WarningSTO26 min
Mar 4, 2:37 PM PSTSevere Thunderstorm WarningSTO23 min
Mar 4, 2:59 PM PSTSevere Thunderstorm WarningSTO31 min
Mar 4, 3:23 PM PSTSevere Thunderstorm WarningSTO37 min
Mar 4, 5:27 PM PSTSevere Thunderstorm WarningSTO63 min
May 3, 5:28 PM PDTSevere Thunderstorm WarningSTO62 min
May 30, 12:52 PM PDTSevere Thunderstorm WarningSTO24 min
Jun 2, 8:08 PM PDTSevere Thunderstorm WarningSTO37 min
Jun 2, 8:59 PM PDTSpecial Weather StatementSTO61 min
Jun 3, 3:55 AM PDTSpecial Weather StatementSTO50 min
Jun 3, 4:44 PM PDTMesoscale DiscussionSPC91 min
Jun 11, 5:55 PM PDTSpecial Weather StatementSTO65 min
Jun 11, 6:36 PM PDTSevere Thunderstorm WarningSTO54 min
Jul 28, 4:22 PM PDTSevere Thunderstorm WarningSTO29 min
Oct 13, 8:45 AM PDTAreal Flood AdvisorySTO12 hr
Dec 21, 4:37 PM PSTSpecial Weather StatementSTO53 min
Dec 21, 6:04 PM PSTSpecial Weather StatementSTO71 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 archive20082010

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.