Alert archive / New Hampshire

Weather alerts in Belknap County, New Hampshire

2,580 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Belknap County and its neighbors

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

Alerts
2,580
Warnings
639
Watches
443
Advisories
676
Busiest year
2008172 alerts
Average year
66over 39 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, 100% of tornado reports in Belknap County fell inside a tornado warning issued on average 7 minutes before, and 50% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
20082150%3100%8 min
201510100%0
2020110%1100%5 min

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008241058%1479%25 min
2009141029%5100%24 min
201011918%367%22 min
2011181517%771%18 min
2012201525%2584%24 min
2013201715%250%28 min
2014171229%978%24 min
201525238%7100%21 min
2016990%1090%32 min
2017151313%2100%20 min
201815147%683%20 min
20195420%250%4 min
20209722%978%7 min
202121210%1292%25 min
202215150%1173%23 min
20234250%1100%24 min
20248713%367%16 min
20256517%1675%19 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
20085260%250%32 min
20092150%2100%79 min
2010110%0
201110100%20%
201220100%0
2013440%1100%34 min
20146350%0
201510100%0
20175420%2100%27 min
201820100%0
20203167%0
2021220%3100%134 min
202210100%0
202310910%7100%136 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
Jul 16, 3:15 PM EDTSevere Thunderstorm WarningGYX45 min
Jul 2, 6:15 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 6, 8:56 PM EDTSevere Thunderstorm WarningGYX50 min
May 15, 7:59 AM EDTRiver Flood WarningGYX14 hr
Mar 17, 6:59 AM EDTRiver Flood WarningGYX14 hr
Feb 22, 1:37 AM ESTWinter Storm WarningGYX44 hr
Feb 19, 12:54 PM ESTWinter Storm WarningGYX42 hr
Jan 24, 12:39 PM ESTWinter Storm WarningGYX60 hr
Jan 22, 12:38 PM ESTExtreme Cold WarningGYX45 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.