Alert archive / North Dakota

Weather alerts in Morton County, North Dakota

2,644 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Morton County and its neighbors

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

Alerts
2,644
Warnings
1,256
Watches
452
Advisories
112
Busiest year
2011175 alerts
Average year
64over 41 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, 59% of tornado reports in Morton County fell inside a tornado warning issued on average 13 minutes before, and 70% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
200813654%580%20 min
200940100%0
201014193%333%0 min
201118572%683%11 min
20134175%333%32 min
201420100%0
201520100%0
201620100%20%
20184250%475%7 min
202020100%10%
20258713%367%9 min
Share of tornado reports inside a tornado warning, by year.

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008552162%1883%27 min
2009221055%786%22 min
2010422638%4163%25 min
2011673154%4591%27 min
201216850%367%28 min
2013362433%2688%32 min
2014221532%1593%23 min
2015252020%2471%24 min
2016433812%4195%27 min
2017151220%1191%27 min
2018372143%2576%26 min
2019322134%1989%22 min
2020372630%1392%27 min
2021281836%2596%31 min
2022221818%11100%17 min
2023272122%1979%19 min
2024231535%1587%19 min
2025332427%2396%27 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
200940100%0
20103167%250%86 min
20118450%367%18 min
2013220%0
2015110%0
201810100%0
2021110%0
2022110%0
202430100%0
202510100%0

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 9, 1:15 PM CDTRed Flag WarningBIS32 hr
Sep 6, 12:11 PM CDTSevere Thunderstorm WarningBIS49 min
Sep 6, 10:32 AM CDTSevere Thunderstorm WarningBIS58 min
Sep 6, 9:50 AM CDTSevere Thunderstorm WarningBIS55 min
Aug 30, 7:41 PM CDTSevere Thunderstorm WarningBIS49 min
Aug 30, 6:42 PM CDTSevere Thunderstorm WarningBIS63 min
Aug 30, 5:58 PM CDTSevere Thunderstorm WarningBIS62 min
Aug 30, 5:03 PM CDTSevere Thunderstorm WarningBIS57 min
Aug 30, 4:41 PM CDTSevere Thunderstorm WarningBIS64 min
Aug 11, 10:20 PM CDTSevere Thunderstorm Warning Considerable damage threatBIS55 min
Aug 11, 10:06 PM CDTSevere Thunderstorm Warning Considerable damage threatBIS24 min
Aug 11, 9:49 PM CDTSevere Thunderstorm Warning Considerable damage threatBIS41 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.