Alert archive / Wyoming

Weather alerts in Sheridan County, Wyoming

2,111 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
2,111
Warnings
550
Watches
308
Advisories
202
Busiest year
2025164 alerts
Average year
57over 37 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, of tornado reports in Sheridan County fell inside a tornado warning, and 100% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
201020100%0
201110100%0

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
200822959%1776%20 min
200910550%1070%26 min
201018572%978%19 min
201111464%956%30 min
2013221532%3181%27 min
201415473%1050%10 min
20158450%540%6 min
20169456%1145%12 min
20174175%250%35 min
201817571%1267%18 min
201918761%1369%23 min
2020010%
202130100%80%
202211464%1346%28 min
20239544%1250%15 min
20248363%1457%6 min
202520290%450%23 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2010110%2100%16 min
201130100%0
20133167%250%24 min
201410100%0
2015220%863%76 min
202310100%0
202560100%10%

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 3, 2:19 PM MDTRed Flag WarningBYZ31 hr
Sep 2, 12:10 PM MDTRed Flag WarningBYZ33 hr
Aug 7, 12:13 PM MDTRed Flag WarningBYZ33 hr
Jul 31, 1:23 PM MDTRed Flag WarningBYZ61 hr
Jul 31, 12:29 PM MDTExtreme Heat WarningBYZ34 hr
Jul 29, 8:30 PM MDTFlash Flood WarningBYZ3 hr
Jul 26, 3:59 PM MDTFlash Flood WarningBYZ3 hr
Jul 24, 1:09 PM MDTRed Flag WarningBYZ32 hr
Jul 23, 12:52 PM MDTExtreme Heat WarningBYZ4 days
Jul 19, 5:28 PM MDTSevere Thunderstorm WarningBYZ46 min
Jul 19, 4:42 PM MDTSevere Thunderstorm WarningBYZ48 min
Jul 18, 4:33 PM MDTFlash Flood WarningBYZ3 hr

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.