Alert archive / Massachusetts

Weather alerts in Essex County, Massachusetts

3,273 weather alerts since 1986, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Essex County and its neighbors

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

Alerts
3,273
Warnings
835
Watches
559
Advisories
1,096
Busiest year
2010214 alerts
Average year
82over 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, of tornado reports in Essex County fell inside a tornado warning, and 100% of the tornado warnings had no report inside them.

Tornado warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
201210100%0
201340100%0
201420100%0
201520100%0
201810100%0
201910100%0
202120100%0
202310100%0

Severe thunderstorm warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008322716%4183%20 min
20099544%1250%8 min
2010171229%3485%19 min
2011880%2685%38 min
2012121017%1669%27 min
20135420%633%8 min
2014181233%4766%25 min
201514657%2665%23 min
201612925%3866%19 min
20177443%3571%38 min
20189544%1735%13 min
2019141121%1735%14 min
2020191616%2479%32 min
2021151313%2374%23 min
20227614%888%17 min
20239722%1080%27 min
20249811%4100%19 min
202510910%8100%31 min

Flash flood warnings by year

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
2008110%10%
200920100%0
2010110%3100%47 min
20112150%1650%63 min
201220100%0
20132150%520%51 min
20148363%743%40 min
201510100%0
2016110%1100%3 min
201710100%30%
20184325%43100%62 min
202030100%0
202170100%20%
202220100%0
202312375%1100%266 min
2025110%2100%54 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 25, 1:53 AM EDTCoastal Flood WarningBOX61 hr
Sep 24, 12:38 PM EDTHigh Wind WarningBOX62 hr
Aug 8, 6:58 PM EDTSevere Thunderstorm WarningBOX45 min
Jul 16, 5:47 PM EDTSevere Thunderstorm WarningBOX34 min
Jul 16, 5:23 PM EDTSevere Thunderstorm WarningBOX37 min
Jul 16, 4:58 PM EDTSevere Thunderstorm WarningBOX47 min
Jun 30, 1:38 AM EDTExtreme Heat WarningBOX4 days
Jun 26, 5:44 PM EDTSevere Thunderstorm WarningBOX48 min
Mar 16, 12:11 AM EDTHigh Wind WarningBOX30 hr
Feb 21, 12:29 PM ESTWinter Storm WarningBOX52 hr
Feb 21, 12:29 PM ESTBlizzard WarningBOX55 hr
Feb 7, 1:15 AM ESTWinter Storm WarningBOX18 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.