Severe Thunderstorm Warnings in Sherman County, Kansas

1,210 severe thunderstorm warnings since 1986. An alert counts here when it covered this county. The archive of severe thunderstorm warnings reaches back to 1986.

Sherman County and its neighbors

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

Severe Thunderstorm Warnings: 1,210
Busiest year: 201679 severe thunderstorm warnings
Average year: 30over 41 years on file

Over time

By year

Before October 2007 these were issued for whole counties, and a storm crossing three counties was often three warnings; since then one polygon follows the storm. The count changed with the practice, not only with the weather.

Warning verification

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

From 2008 to 2025, 79% of hail, wind and damage reports in Sherman County fell inside a severe thunderstorm warning issued on average 27 minutes before, and 51% of the severe thunderstorm warnings had no report inside them.

Severe thunderstorm warnings by year

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
2008	28	13	54%	20	70%	24 min
2009	34	19	44%	39	92%	29 min
2010	40	20	50%	28	89%	30 min
2011	41	16	61%	26	69%	37 min
2012	13	4	69%	2	0%
2013	44	24	45%	37	95%	27 min
2014	53	24	55%	51	84%	32 min
2015	49	17	65%	20	65%	21 min
2016	80	26	68%	49	88%	27 min
2017	56	26	54%	46	78%	26 min
2018	56	27	52%	64	72%	22 min
2019	57	34	40%	38	61%	23 min
2020	43	22	49%	29	100%	39 min
2021	29	21	28%	32	72%	30 min
2022	21	7	67%	14	36%	26 min
2023	55	33	40%	61	92%	21 min
2024	45	23	49%	31	74%	26 min
2025	49	29	41%	34	74%	21 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.

The latest severe thunderstorm warnings

The most recent on file, newest first.

Issued	Product	Office	Lasted
Sep 19, 7:07 PM MDT	Severe Thunderstorm Warning	GLD	23 min
Sep 19, 5:38 PM MDT	Severe Thunderstorm Warning Considerable damage threat	GLD	37 min
Sep 18, 5:38 PM MDT	Severe Thunderstorm Warning	GLD	67 min
Sep 18, 4:31 PM MDT	Severe Thunderstorm Warning Considerable damage threat	GLD	59 min
Aug 19, 9:10 PM MDT	Severe Thunderstorm Warning	GLD	68 min
Aug 19, 7:56 PM MDT	Severe Thunderstorm Warning	GLD	52 min
Aug 13, 7:57 PM MDT	Severe Thunderstorm Warning	GLD	63 min
Jul 9, 8:12 PM MDT	Severe Thunderstorm Warning Considerable damage threat	GLD	78 min
Jul 9, 7:46 PM MDT	Severe Thunderstorm Warning Considerable damage threat	GLD	29 min
Jul 9, 7:26 PM MDT	Severe Thunderstorm Warning Destructive damage threat	GLD	49 min
Jul 9, 6:56 PM MDT	Severe Thunderstorm Warning	GLD	64 min
Jul 8, 9:09 PM MDT	Severe Thunderstorm Warning Considerable damage threat	GLD	37 min

Nearby

Alerts in force now Tornadoes on record Forecast The 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.