Alert archive / California / Stanislaus County

Weather alerts in Stanislaus County, California, 2017

24 weather alerts in 2017, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Stanislaus County and its neighbors

Each county as a circle sized by its count in 2017. Tap one for its archive.

Alerts
24
Warnings
18
Watches
0
Advisories
2
Busiest month
January9 alerts
Busiest day
March 21, 20176 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 Stanislaus County in 2017 had a tornado report inside them.

Stanislaus County, 2017

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings20100%0
Severe thunderstorm warnings10100%0
Flash flood warnings00

Each office's whole area, 2017

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Sacramento, CA: tornado warnings30100%10%
NWS Sacramento, CA: severe thunderstorm warnings17571%6100%11 min
NWS Sacramento, CA: flash flood warnings20100%290%

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 8, 2:00 AM PSTAreal Flood AdvisorySTO313 days
Jan 8, 6:22 AM PSTAreal Flood WarningSTO48 hr
Jan 8, 9:13 AM PSTAreal Flood WarningSTO48 hr
Jan 10, 3:10 AM PSTAreal Flood WarningSTO60 hr
Jan 12, 2:31 PM PSTAreal Flood WarningSTO24 hr
Jan 13, 2:31 PM PSTAreal Flood WarningSTO24 hr
Jan 14, 1:55 PM PSTAreal Flood WarningSTO36 hr
Jan 14, 2:08 PM PSTAreal Flood WarningSTO36 hr
Jan 22, 1:43 PM PSTMesoscale DiscussionSPC2 hr
Feb 7, 4:20 AM PSTAreal Flood WarningSTO36 hr
Feb 7, 9:26 AM PSTAreal Flood WarningSTO6 days
Feb 17, 2:53 PM PSTRiver Flood WarningHNX24 hr
Feb 18, 3:58 PM PSTAreal Flood WarningSTO5 days
Feb 19, 3:24 PM PSTRiver Flood WarningSTO10 days
Feb 20, 2:42 AM PSTRiver Flood WarningSTO24 hr
Feb 22, 1:44 AM PSTRiver Flood WarningSTO24 hr
Mar 3, 2:26 PM PSTRiver Flood WarningSTO47 hr
Mar 21, 12:27 PM PDTAreal Flood AdvisorySTO3 hr
Mar 21, 12:33 PM PDTSpecial Weather StatementSTO27 min
Mar 21, 12:34 PM PDTMesoscale DiscussionSPC116 min
Mar 21, 12:48 PM PDTTornado WarningSTO27 min
Mar 21, 1:15 PM PDTTornado WarningSTO32 min
Mar 21, 1:50 PM PDTSevere Thunderstorm WarningSTO40 min
Sep 11, 8:04 PM PDTSpecial Weather StatementSTO41 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 archive20162018

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.