Alert archive / California / Shasta County

Weather alerts in Shasta County, California, 2013

18 weather alerts in 2013, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Shasta County and its neighbors

Each county as a circle sized by its count in 2013. Tap one for its archive.

Alerts
18
Warnings
3
Watches
0
Advisories
0
Busiest month
August6 alerts
Busiest day
August 21, 20133 alerts

Over time

By month

Warning verification

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

Shasta County, 2013

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings220%2100%2 min
Flash flood warnings10100%0

Each office's whole area, 2013

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Sacramento, CA: tornado warnings220%633%11 min
NWS Sacramento, CA: severe thunderstorm warnings16288%450%2 min
NWS Sacramento, CA: flash flood warnings30100%0

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 6, 11:57 AM PSTSpecial Weather StatementSTO48 min
Mar 30, 3:59 PM PDTSpecial Weather StatementSTO46 min
Apr 4, 6:45 PM PDTSpecial Weather StatementSTO45 min
Apr 4, 8:09 PM PDTFlash Flood WarningSTO67 min
Apr 7, 3:43 PM PDTSpecial Weather StatementSTO47 min
Apr 7, 4:35 PM PDTSpecial Weather StatementSTO40 min
May 5, 2:47 PM PDTMesoscale DiscussionSPC118 min
May 8, 5:36 PM PDTSpecial Weather StatementSTO54 min
Jul 2, 8:03 PM PDTSpecial Weather StatementSTO42 min
Jul 2, 8:27 PM PDTSpecial Weather StatementSTO33 min
Jul 3, 7:02 PM PDTSevere Thunderstorm WarningSTO28 min
Jul 27, 7:40 PM PDTSpecial Weather StatementSTO50 min
Aug 21, 12:30 PM PDTMesoscale DiscussionSPC3 hr
Aug 21, 3:00 PM PDTSpecial Weather StatementSTO45 min
Aug 21, 3:18 PM PDTSevere Thunderstorm WarningSTO42 min
Aug 21, 5:20 PM PDTSpecial Weather StatementSTO40 min
Aug 21, 5:45 PM PDTSpecial Weather StatementSTO45 min
Aug 22, 11:54 AM PDTMesoscale DiscussionSPC2 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 archive20122014

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.