Alert archive / North Carolina

Weather alerts in Guilford County, North Carolina

3,746 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Guilford County and its neighbors

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

Alerts
3,746
Warnings
1,085
Watches
445
Advisories
817
Busiest year
2011237 alerts
Average year
94over 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, 94% of tornado reports in Guilford County fell inside a tornado warning issued on average 12 minutes before, and 72% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
20087443%5100%23 min
20106183%2100%16 min
201130100%0
201310100%0
2018110%786%4 min
201940100%0
20204175%0
20214250%2100%6 min
202210100%0
202310100%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
2008361753%1794%26 min
2009251444%1587%19 min
201025238%3272%17 min
2011342624%4190%21 min
2012272219%3291%33 min
2013171512%2986%20 min
2014201715%19100%27 min
2015141029%1587%19 min
2016332815%3194%22 min
2017262023%3097%27 min
2018211529%1155%19 min
201932299%5472%24 min
2020161225%1694%26 min
2021181422%2080%20 min
2022332815%2186%22 min
202330287%3388%21 min
2024231917%771%24 min
2025302710%3591%23 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
200810640%5100%61 min
20096350%4100%54 min
201016944%1788%100 min
201111736%888%45 min
201211736%1283%50 min
20137529%8100%46 min
201410100%0
20156433%5100%56 min
20167529%743%20 min
20174250%5100%63 min
2018131023%1794%144 min
20198625%2387%86 min
202010730%9100%124 min
20214250%1100%17 min
20227271%1100%83 min
20238363%888%24 min
202411645%13100%81 min
2025131115%1392%107 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, 5:31 PM EDTSevere Thunderstorm WarningRAH59 min
Sep 21, 4:56 PM EDTSevere Thunderstorm WarningRAH64 min
Sep 18, 3:10 PM EDTFlash Flood WarningRAH2 hr
Sep 18, 2:57 PM EDTSevere Thunderstorm Warning Considerable damage threatRAH48 min
Sep 18, 2:19 PM EDTSevere Thunderstorm WarningRAH41 min
Sep 5, 1:23 PM EDTSevere Thunderstorm WarningRAH52 min
Sep 4, 6:31 PM EDTAreal Flood WarningRAH3 hr
Sep 4, 6:09 PM EDTSevere Thunderstorm WarningRAH51 min
Sep 4, 5:45 PM EDTSevere Thunderstorm WarningRAH45 min
Sep 4, 4:07 PM EDTSevere Thunderstorm WarningRAH38 min
Aug 22, 10:15 PM EDTSevere Thunderstorm WarningRAH45 min
Aug 17, 12:31 AM EDTSevere Thunderstorm WarningRAH59 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.