Alert archive / North Carolina

Weather alerts in Chatham County, North Carolina

3,895 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Chatham County and its neighbors

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

Alerts
3,895
Warnings
1,194
Watches
493
Advisories
808
Busiest year
2018223 alerts
Average year
95over 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, 88% of tornado reports in Chatham County fell inside a tornado warning issued on average 11 minutes before, and 67% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
20083233%2100%14 min
200910100%0
20113233%1100%8 min
201310100%0
201430100%0
20152150%0
20167186%0
20196433%1100%22 min
20203167%0
2021110%0
202220100%0
202310100%0
202440100%10%
20252150%3100%6 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
2008392146%2488%22 min
2009231343%4100%21 min
2010181328%1385%13 min
2011332524%2576%15 min
2012372824%2095%22 min
201314140%9100%28 min
2014201715%10100%21 min
2015352431%1989%21 min
2016432835%2195%30 min
2017211814%8100%25 min
2018342526%2879%23 min
2019413417%2564%18 min
2020251924%2171%29 min
2021231535%1173%19 min
202244417%2979%21 min
202335329%1593%24 min
202425238%1191%27 min
2025453816%3792%20 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
20086517%4100%64 min
2009220%0
20103233%1100%92 min
20114250%4100%34 min
2012220%2100%27 min
2013220%5100%38 min
2014110%0
20155420%0
20165340%1100%244 min
201811736%3100%386 min
2019110%0
2020220%10%
20214250%1100%73 min
20225340%0
20235260%4100%65 min
2024141121%2100%244 min
2025660%10100%188 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 21, 5:52 PM EDTSevere Thunderstorm WarningRAH30 min
Sep 18, 4:26 PM EDTSevere Thunderstorm WarningRAH37 min
Sep 18, 3:44 PM EDTSevere Thunderstorm WarningRAH46 min
Sep 18, 2:57 PM EDTSevere Thunderstorm Warning Considerable damage threatRAH48 min
Sep 5, 4:12 PM EDTSevere Thunderstorm WarningRAH18 min
Aug 21, 6:34 PM EDTSevere Thunderstorm WarningRAH41 min
Aug 21, 6:28 PM EDTSevere Thunderstorm Warning Considerable damage threatRAH47 min
Aug 21, 6:03 PM EDTTornado WarningRAH27 min
Aug 21, 5:49 PM EDTSevere Thunderstorm WarningRAH41 min
Aug 17, 5:22 PM EDTSevere Thunderstorm WarningRAH38 min
Aug 16, 2:49 PM EDTSevere Thunderstorm WarningRAH41 min
Aug 16, 2:43 PM EDTSevere Thunderstorm WarningRAH27 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.