Alert archive / Nebraska

Weather alerts in Sheridan County, Nebraska

4,436 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Sheridan County and its neighbors

Each county as a circle sized by its count since 1986. Tap one for its archive.

Alerts
4,436
Warnings
1,659
Watches
711
Advisories
547
Busiest year
2026255 alerts
Average year
111over 40 years on file

Over time

By year

Before late 2005 the archive holds only tornado, severe thunderstorm, flash flood and marine warnings, and from 1997 SPC's watches, so the jump that year is the archive widening, not the weather.

By month of the year

Warning verification

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

From 2008 to 2025, 11% of tornado reports in Sheridan County fell inside a tornado warning issued on average 15 minutes before, and 76% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
201030100%20%
201110100%0
201320100%20%
201410100%20%
201520100%20%
20165180%617%27 min
20173167%250%3 min
2021010%
2022010%
2023010%
202410100%0
2025330%0
Share of tornado reports inside a tornado warning, by year.

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008611772%1580%29 min
2009481863%21100%19 min
2010241442%1989%22 min
2011312035%3491%19 min
201210550%978%12 min
2013432542%3194%18 min
2014241442%2391%21 min
2015412832%5098%19 min
2016322038%2483%19 min
2017281354%1392%15 min
2018392341%2488%24 min
2019312132%2893%24 min
2020251540%1587%11 min
2021281836%11100%26 min
2022281546%1479%30 min
2023552555%4391%23 min
2024441761%2195%24 min
2025441566%1878%16 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2009110%1100%10 min
201010100%10%
2011110%1100%236 min
2018010%
201910100%0
20225180%10%
2023110%1100%10 min

Years from 2008, the first full year of storm-based warnings. The year still running is on its own page.

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.

By product

Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.

The latest warnings

The most recent on file, newest first.

IssuedProductOfficeLasted
Sep 19, 4:49 PM MDTSevere Thunderstorm WarningLBF56 min
Sep 10, 12:32 PM MDTRed Flag WarningLBF30 hr
Sep 5, 3:04 PM MDTSevere Thunderstorm WarningLBF26 min
Sep 3, 12:14 PM MDTRed Flag WarningLBF8 hr
Aug 24, 6:04 PM MDTSevere Thunderstorm WarningLBF41 min
Aug 23, 3:31 PM MDTSevere Thunderstorm WarningLBF44 min
Aug 21, 6:05 AM MDTSevere Thunderstorm WarningLBF55 min
Aug 17, 6:10 PM MDTSevere Thunderstorm Warning Considerable damage threatLBF50 min
Aug 17, 5:53 PM MDTSevere Thunderstorm WarningLBF52 min
Aug 16, 10:16 PM MDTSevere Thunderstorm WarningLBF44 min
Aug 16, 9:46 PM MDTSevere Thunderstorm WarningLBF44 min
Aug 16, 9:12 PM MDTSevere Thunderstorm WarningLBF48 min

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive

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.