Alert archive / California / Stanislaus County

Weather alerts in Stanislaus County, California, 2019

10 weather alerts in 2019, 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 2019. Tap one for its archive.

Alerts
10
Warnings
3
Watches
0
Advisories
2
Busiest month
February3 alerts
Busiest day
January 17, 20191 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 1 tornado warnings covering Stanislaus County in 2019 had a tornado report inside them.

Stanislaus County, 2019

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

Each office's whole area, 2019

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Sacramento, CA: tornado warnings9189%333%5 min
NWS Sacramento, CA: severe thunderstorm warnings17665%2454%16 min
NWS Sacramento, CA: flash flood warnings11464%2143%52 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 16, 7:15 PM PSTAreal Flood AdvisorySTO10 hr
Jan 20, 3:29 PM PSTTornado WarningSTO46 min
Feb 2, 6:11 PM PSTAreal Flood WarningSTO23 hr
Feb 13, 8:13 AM PSTAreal Flood WarningSTO12 hr
Feb 14, 10:50 AM PSTMesoscale DiscussionSPC115 min
Mar 6, 1:28 PM PSTAreal Flood AdvisorySTO5 hr
Mar 27, 2:36 PM PDTSpecial Weather StatementSTO54 min
May 16, 3:38 PM PDTSpecial Weather StatementSTO37 min
May 19, 3:23 PM PDTSpecial Weather StatementSTO37 min
May 19, 8:05 PM PDTSpecial Weather StatementSTO55 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 archive20182020

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.