Alert archive / New Hampshire

Weather alerts in Carroll County, New Hampshire

3,192 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Carroll County and its neighbors

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

Alerts
3,192
Warnings
919
Watches
471
Advisories
903
Busiest year
2008194 alerts
Average year
78over 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, 40% of tornado reports in Carroll County fell inside a tornado warning issued on average 8 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
20082150%450%8 min
201010100%0
201510100%0
20173167%0
201820100%0
2020110%10%

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008311552%1771%26 min
2009181328%4100%24 min
2010151127%5100%27 min
2011252212%16100%25 min
2012271737%978%26 min
2013312616%1593%21 min
2014211529%1663%29 min
2015292417%1493%26 min
2016201810%10100%26 min
2017272122%2688%24 min
201811918%3100%17 min
20194250%367%36 min
2020211529%1283%14 min
2021232013%1889%15 min
202218176%3770%21 min
20237443%367%7 min
20248713%1567%21 min
20257614%1136%25 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
20083167%20%
200910100%0
2010110%0
20114325%875%202 min
20124175%20%
20133233%2100%121 min
201410640%540%62 min
20152150%0
20179633%0
2019110%2100%30 min
20208538%4100%35 min
2021110%1100%2 min
2022010%
202316944%888%158 min
20243233%2100%175 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
Aug 8, 4:40 PM EDTSevere Thunderstorm WarningGYX50 min
Jul 16, 3:15 PM EDTSevere Thunderstorm WarningGYX45 min
Jul 14, 10:21 PM EDTSevere Thunderstorm WarningGYX17 min
Jul 14, 9:51 PM EDTSevere Thunderstorm WarningGYX39 min
Jul 14, 9:20 PM EDTSevere Thunderstorm WarningGYX40 min
Jul 1, 9:30 PM EDTSevere Thunderstorm WarningGYX45 min
Jun 30, 1:57 PM EDTExtreme Heat WarningGYX3 days
Jun 18, 4:21 PM EDTSevere Thunderstorm WarningGYX54 min
Jun 18, 3:40 PM EDTSevere Thunderstorm WarningGYX65 min
Jun 18, 3:07 PM EDTSevere Thunderstorm WarningGYX53 min
Jun 11, 12:33 AM EDTFlash Flood WarningGYX3 hr
Jun 6, 8:56 PM EDTSevere Thunderstorm WarningGYX50 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.