Alert archive / California / Butte County

Weather alerts in Butte County, California, 2015

20 weather alerts in 2015, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Butte County and its neighbors

Each county as a circle sized by its count in 2015. Tap one for its archive.

Alerts
20
Warnings
4
Watches
1
Advisories
2
Busiest month
April6 alerts
Busiest day
April 7, 20153 alerts

Over time

By month

Warning verification

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

0 of 2 tornado warnings covering Butte County in 2015 had a tornado report inside them.

Butte County, 2015

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings20100%0
Severe thunderstorm warnings20100%10%
Flash flood warnings00

Each office's whole area, 2015

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Sacramento, CA: tornado warnings60100%90%
NWS Sacramento, CA: severe thunderstorm warnings21386%1338%10 min
NWS Sacramento, CA: flash flood warnings5180%729%114 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
Feb 4, 11:30 AM PSTFlood WatchSTO65 hr
Feb 8, 1:30 PM PSTMesoscale DiscussionSPC90 min
Feb 27, 3:58 PM PSTSevere Thunderstorm WarningSTO62 min
Feb 27, 5:15 PM PSTSpecial Weather StatementSTO45 min
Apr 7, 3:54 PM PDTTornado WarningSTO49 min
Apr 7, 4:00 PM PDTTornado WarningSTO43 min
Apr 7, 4:16 PM PDTMesoscale DiscussionSPC119 min
Apr 23, 7:48 PM PDTSpecial Weather StatementSTO42 min
Apr 23, 7:52 PM PDTSevere Thunderstorm WarningSTO38 min
Apr 23, 8:42 PM PDTSpecial Weather StatementSTO63 min
Jun 4, 2:24 PM PDTSpecial Weather StatementSTO66 min
Jun 6, 5:15 PM PDTSpecial Weather StatementSTO60 min
Jul 8, 1:44 PM PDTSpecial Weather StatementSTO46 min
Oct 18, 7:09 PM PDTSpecial Weather StatementSTO51 min
Nov 2, 3:44 PM PSTSpecial Weather StatementSTO46 min
Nov 2, 4:18 PM PSTSpecial Weather StatementSTO42 min
Nov 24, 12:14 PM PSTSpecial Weather StatementSTO61 min
Nov 24, 12:18 PM PSTSpecial Weather StatementSTO57 min
Dec 13, 9:19 AM PSTAreal Flood AdvisorySTO4 hr
Dec 13, 9:41 AM PSTAreal Flood AdvisorySTO3 hr

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 archive20142016

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.