Alert archive / Massachusetts / Essex County
Weather alerts in Essex County, Massachusetts, 2021
164 weather alerts in 2021, 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 in 2021. Tap one for its archive.
- Alerts
- 164
- Warnings
- 40
- Watches
- 17
- Advisories
- 48
- Busiest month
- July37 alerts
- Busiest day
- July 23, 20216 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
0 of 2 tornado warnings covering Essex County in 2021 had a tornado report inside them.
Essex County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 2 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 15 | 13 | 13% | 23 | 74% | 23 min |
| Flash flood warnings | 7 | 0 | 100% | 2 | 0% |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Boston/Norton, MA: tornado warnings | 23 | 6 | 74% | 14 | 50% | 18 min |
| NWS Boston/Norton, MA: severe thunderstorm warnings | 131 | 84 | 36% | 358 | 80% | 27 min |
| NWS Boston/Norton, MA: flash flood warnings | 38 | 1 | 97% | 5 | 60% | 141 min |
An office's figures cover every county it serves, including across state lines.
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.
The alerts
Every alert, in the order issued. Times are local, Eastern Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 2, 3:56 PM EST | Winter Weather Advisory | BOX | 35 hr |
| Jan 5, 7:54 PM EST | Coastal Flood Statement | BOX | 11 hr |
| Jan 15, 3:35 PM EST | Coastal Flood Advisory | BOX | 23 hr |
| Jan 16, 3:03 AM EST | Wind Advisory | BOX | 9 hr |
| Jan 23, 6:43 AM EST | Special Weather Statement | BOX | 62 min |
| Jan 30, 3:28 PM EST | Winter Storm Watch | BOX | 24 hr |
| Jan 31, 3:37 PM EST | Winter Storm Warning | BOX | 37 hr |
| Jan 31, 3:52 PM EST | Coastal Flood Watch | BOX | 12 hr |
| Feb 1, 3:31 AM EST | Coastal Flood Advisory | BOX | 37 hr |
| Feb 1, 7:24 PM EST | Winter Weather Advisory | BOX | 6 hr |
| Feb 1, 10:31 PM EST | Wind Advisory | BOX | 6 hr |
| Feb 2, 4:07 AM EST | Winter Weather Advisory | BOX | 11 hr |
| Feb 2, 7:03 PM EST | Coastal Flood Advisory | BOX | 10 hr |
| Feb 5, 3:27 PM EST | Winter Storm Watch | BOX | 24 hr |
| Feb 6, 3:20 AM EST | Winter Storm Warning | BOX | 42 hr |
| Feb 6, 3:27 PM EST | Winter Weather Advisory | BOX | 30 hr |
| Feb 8, 2:56 PM EST | Winter Weather Advisory | BOX | 28 hr |
| Feb 9, 1:59 AM EST | Winter Storm Warning | BOX | 12 hr |
| Feb 14, 3:31 PM EST | Winter Storm Watch | BOX | 12 hr |
| Feb 15, 3:54 AM EST | Winter Weather Advisory | BOX | 31 hr |
| Feb 16, 3:38 PM EST | Winter Storm Watch | BOX | 24 hr |
| Feb 17, 3:37 PM EST | Winter Weather Advisory | BOX | 56 hr |
| Feb 28, 3:01 PM EST | Wind Advisory | BOX | 48 hr |
| Mar 1, 8:38 AM EST | Coastal Flood Statement | BOX | 5 hr |
| Mar 12, 2:53 AM EST | Wind Advisory | BOX | 28 hr |
| Mar 12, 1:30 PM EST | Red Flag Warning | BOX | 28 hr |
| Mar 13, 3:42 PM EST | Wind Advisory | BOX | 35 hr |
| Mar 14, 3:10 AM EDT | Red Flag Warning | BOX | 17 hr |
| Mar 14, 2:56 PM EDT | Special Weather Statement | BOX | 49 min |
| Mar 15, 10:48 AM EDT | Red Flag Warning | BOX | 10 hr |
| Mar 25, 3:57 PM EDT | Wind Advisory | BOX | 36 hr |
| Mar 28, 3:34 AM EDT | Wind Advisory | BOX | 36 hr |
| Apr 16, 3:42 AM EDT | Wind Advisory | BOX | 15 hr |
| Apr 21, 5:26 PM EDT | Special Weather Statement | BOX | 49 min |
| Apr 28, 4:16 AM EDT | Coastal Flood Statement | BOX | 23 hr |
| Apr 28, 2:50 PM EDT | Coastal Flood Advisory | BOX | 12 hr |
| Apr 29, 3:24 PM EDT | Wind Advisory | BOX | 35 hr |
| Apr 29, 3:29 PM EDT | Coastal Flood Statement | BOX | 13 hr |
| May 26, 3:56 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| May 26, 7:15 PM EDT | Special Weather Statement | BOX | 45 min |
| May 28, 3:46 AM EDT | Coastal Flood Statement | BOX | 24 hr |
| May 29, 4:03 AM EDT | Coastal Flood Statement | BOX | 12 hr |
| May 29, 3:52 PM EDT | Coastal Flood Advisory | BOX | 12 hr |
| Jun 5, 6:35 PM EDT | Special Weather Statement | BOX | 40 min |
| Jun 6, 3:29 AM EDT | Heat Advisory | BOX | 64 hr |
| Jun 7, 3:12 PM EDT | Heat Advisory | BOX | 28 hr |
| Jun 8, 3:12 PM EDT | Special Weather Statement | BOX | 48 min |
| Jun 8, 3:42 PM EDT | Special Weather Statement | BOX | 48 min |
| Jun 8, 4:13 PM EDT | Special Weather Statement | BOX | 47 min |
| Jun 9, 3:12 AM EDT | Heat Advisory | BOX | 17 hr |
| Jun 15, 2:38 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 15, 5:13 PM EDT | Severe Thunderstorm Warning | BOX | 62 min |
| Jun 15, 5:28 PM EDT | Severe Thunderstorm Warning | BOX | 32 min |
| Jun 26, 3:15 PM EDT | Heat Advisory | BOX | 4 days |
| Jun 30, 2:16 PM EDT | Mesoscale Discussion | SPC | 119 min |
| Jun 30, 3:21 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 30, 5:25 PM EDT | Severe Thunderstorm Warning | BOX | 49 min |
| Jun 30, 5:43 PM EDT | Severe Thunderstorm Warning | BOX | 51 min |
| Jul 2, 2:23 AM EDT | Areal Flood Warning | BOX | 3 hr |
| Jul 2, 2:34 AM EDT | Special Weather Statement | BOX | 86 min |
| Jul 2, 4:24 AM EDT | Rip Current Statement | BOX | 16 hr |
| Jul 2, 7:57 PM EDT | Rip Current Statement | BOX | 24 hr |
| Jul 6, 3:33 AM EDT | Heat Advisory | BOX | 39 hr |
| Jul 6, 1:13 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 6, 5:13 PM EDT | Severe Thunderstorm Warning | BOX | 62 min |
| Jul 6, 5:19 PM EDT | Special Weather Statement | BOX | 41 min |
| Jul 6, 6:00 PM EDT | Special Weather Statement | BOX | 30 min |
| Jul 7, 2:41 PM EDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jul 7, 4:05 PM EDT | Special Weather Statement | BOX | 40 min |
| Jul 7, 4:33 PM EDT | Severe Thunderstorm Warning | BOX | 57 min |
| Jul 7, 4:48 PM EDT | Mesoscale Discussion | SPC | 87 min |
| Jul 8, 4:20 AM EDT | Flash Flood Watch | BOX | 36 hr |
| Jul 8, 4:57 AM EDT | Tropical Storm Warning | BOX | 36 hr |
| Jul 9, 9:32 AM EDT | Flash Flood Warning | BOX | 6 hr |
| Jul 9, 12:19 PM EDT | River Flood Warning | BOX | 8 hr |
| Jul 9, 3:24 PM EDT | Areal Flood Warning | BOX | 5 hr |
| Jul 11, 3:34 PM EDT | Flash Flood Watch | BOX | 21 hr |
| Jul 12, 11:48 AM EDT | River Flood Warning | BOX | 3 hr |
| Jul 14, 12:32 AM EDT | Dense Fog Advisory | BOX | 9 hr |
| Jul 16, 9:38 AM EDT | Heat Advisory | BOX | 9 hr |
| Jul 21, 12:02 AM EDT | Special Weather Statement | BOX | 58 min |
| Jul 23, 2:49 PM EDT | Coastal Flood Statement | BOX | 11 hr |
| Jul 23, 3:04 PM EDT | Special Weather Statement | BOX | 26 min |
| Jul 23, 3:28 PM EDT | Severe Thunderstorm Warning | BOX | 47 min |
| Jul 23, 4:41 PM EDT | Special Weather Statement | BOX | 34 min |
| Jul 23, 4:57 PM EDT | Severe Thunderstorm Warning | BOX | 63 min |
| Jul 23, 5:47 PM EDT | Mesoscale Discussion | SPC | 58 min |
| Jul 27, 2:47 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 27, 6:09 PM EDT | Mesoscale Discussion | SPC | 96 min |
| Jul 27, 6:33 PM EDT | Severe Thunderstorm Warning | BOX | 57 min |
| Jul 27, 6:50 PM EDT | Special Weather Statement | BOX | 25 min |
| Jul 27, 7:26 PM EDT | Severe Thunderstorm Warning | BOX | 64 min |
| Jul 29, 11:15 PM EDT | Special Weather Statement | BOX | 45 min |
| Jul 29, 11:30 PM EDT | Flash Flood Warning | BOX | 96 min |
| Jul 30, 12:34 AM EDT | Special Weather Statement | BOX | 41 min |
| Aug 4, 3:11 AM EDT | Flash Flood Watch | BOX | 34 hr |
| Aug 10, 3:22 AM EDT | Excessive Heat Watch | BOX | 60 hr |
| Aug 10, 3:22 AM EDT | Heat Advisory | BOX | 41 hr |
| Aug 11, 3:28 PM EDT | Excessive Heat Warning | BOX | 29 hr |
| Aug 12, 2:53 PM EDT | Heat Advisory | BOX | 29 hr |
| Aug 12, 3:50 PM EDT | Mesoscale Discussion | SPC | 55 min |
| Aug 12, 6:44 PM EDT | Mesoscale Discussion | SPC | 61 min |
| Aug 19, 10:46 AM EDT | Flash Flood Warning | BOX | 3 hr |
| Aug 19, 11:36 AM EDT | Severe Thunderstorm Warning | BOX | 54 min |
| Aug 19, 11:40 AM EDT | Flash Flood Warning | BOX | 3 hr |
| Aug 19, 12:32 PM EDT | Severe Thunderstorm Warning | BOX | 58 min |
| Aug 19, 12:49 PM EDT | Tornado Warning | BOX | 39 min |
| Aug 19, 1:37 PM EDT | Special Weather Statement | BOX | 38 min |
| Aug 22, 9:43 AM EDT | Coastal Flood Advisory | BOX | 16 hr |
| Aug 25, 2:55 PM EDT | Heat Advisory | BOX | 29 hr |
| Aug 30, 3:12 PM EDT | Flash Flood Watch | BOX | 65 hr |
| Sep 1, 4:00 PM EDT | Wind Advisory | BOX | 19 hr |
| Sep 1, 10:01 PM EDT | Flash Flood Warning | BOX | 8 hr |
| Sep 1, 11:02 PM EDT | Flash Flood Warning | BOX | 8 hr |
| Sep 2, 6:02 AM EDT | Flash Flood Warning | BOX | 3 hr |
| Sep 2, 7:04 AM EDT | Areal Flood Warning | BOX | 11 hr |
| Sep 2, 5:59 PM EDT | River Flood Warning | BOX | 25 hr |
| Sep 3, 9:38 PM EDT | River Flood Warning | BOX | 16 hr |
| Sep 9, 2:57 AM EDT | Rip Current Statement | BOX | 11 hr |
| Sep 9, 4:12 AM EDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 9, 1:55 PM EDT | High Surf Advisory | BOX | 53 hr |
| Sep 13, 2:44 AM EDT | Special Weather Statement | BOX | 46 min |
| Sep 13, 3:14 AM EDT | Severe Thunderstorm Warning | BOX | 31 min |
| Sep 13, 5:24 AM EDT | Special Weather Statement | BOX | 66 min |
| Sep 13, 5:34 AM EDT | Severe Thunderstorm Warning | BOX | 31 min |
| Sep 15, 3:04 PM EDT | Mesoscale Discussion | SPC | 116 min |
| Sep 16, 6:10 AM EDT | Special Weather Statement | BOX | 65 min |
| Sep 17, 3:13 PM EDT | Rip Current Statement | BOX | 53 hr |
| Sep 17, 8:10 PM EDT | Dense Fog Advisory | BOX | 12 hr |
| Sep 23, 9:28 AM EDT | Rip Current Statement | BOX | 35 hr |
| Oct 1, 3:14 AM EDT | Rip Current Statement | BOX | 60 hr |
| Oct 8, 3:02 AM EDT | Coastal Flood Advisory | BOX | 37 hr |
| Oct 10, 2:55 AM EDT | Coastal Flood Statement | BOX | 13 hr |
| Oct 11, 3:43 AM EDT | Coastal Flood Statement | BOX | 14 hr |
| Oct 11, 3:43 AM EDT | Rip Current Statement | BOX | 16 hr |
| Oct 12, 1:11 AM EDT | Dense Fog Advisory | BOX | 8 hr |
| Oct 16, 5:39 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 22, 2:53 PM EDT | Frost Advisory | BOX | 41 hr |
| Oct 24, 2:52 PM EDT | High Wind Watch | BOX | 24 hr |
| Oct 25, 3:47 AM EDT | Flood Watch | BOX | 52 hr |
| Oct 25, 3:12 PM EDT | High Wind Warning | BOX | 48 hr |
| Oct 25, 3:12 PM EDT | Wind Advisory | BOX | 48 hr |
| Oct 25, 3:19 PM EDT | Coastal Flood Advisory | BOX | 40 hr |
| Oct 25, 3:19 PM EDT | Coastal Flood Advisory | BOX | 52 hr |
| Nov 5, 3:45 AM EDT | Coastal Flood Statement | BOX | 11 hr |
| Nov 5, 4:03 PM EDT | Coastal Flood Statement | BOX | 23 hr |
| Nov 6, 3:23 PM EDT | Coastal Flood Statement | BOX | 24 hr |
| Nov 8, 4:11 AM EST | Coastal Flood Statement | BOX | 11 hr |
| Nov 12, 3:13 AM EST | Wind Advisory | BOX | 16 hr |
| Nov 12, 3:20 PM EST | Special Weather Statement | BOX | 40 min |
| Nov 13, 5:55 PM EST | Severe Thunderstorm Warning | BOX | 25 min |
| Nov 22, 2:47 AM EST | Special Weather Statement | BOX | 43 min |
| Nov 22, 3:05 AM EST | Tornado Warning | BOX | 25 min |
| Dec 2, 9:49 PM EST | Special Weather Statement | BOX | 56 min |
| Dec 2, 10:44 PM EST | Special Weather Statement | BOX | 61 min |
| Dec 6, 9:37 PM EST | Special Weather Statement | BOX | 53 min |
| Dec 10, 3:45 PM EST | Wind Advisory | BOX | 36 hr |
| Dec 11, 9:49 PM EST | Mesoscale Discussion | SPC | 116 min |
| Dec 17, 3:11 AM EST | Winter Weather Advisory | BOX | 51 hr |
| Dec 21, 3:26 AM EST | Winter Weather Advisory | BOX | 32 hr |
| Dec 22, 9:18 AM EST | Dense Fog Advisory | BOX | 5 hr |
| Dec 24, 3:39 AM EST | Winter Weather Advisory | BOX | 49 hr |
| Dec 25, 5:44 AM EST | Mesoscale Discussion | SPC | 5 hr |
| Dec 30, 9:25 PM EST | Dense Fog Advisory | BOX | 13 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
| Product | Alerts |
|---|---|
| Severe storms | |
| Severe Thunderstorm Warning | 15 |
| Tornado Warning | 2 |
| Severe Thunderstorm Watch | 5 |
| Mesoscale Discussion | 12 |
| Special Weather Statement | 27 |
| Flooding | |
| Areal Flood Warning | 3 |
| Flash Flood Warning | 7 |
| River Flood Warning | 4 |
| Flash Flood Watch | 4 |
| Flood Watch | 1 |
| Winter | |
| Winter Storm Warning | 3 |
| Winter Storm Watch | 4 |
| Winter Weather Advisory | 10 |
| Heat | |
| Excessive Heat Warning | 1 |
| Excessive Heat Watch | 1 |
| Heat Advisory | 9 |
| Cold | |
| Frost Advisory | 1 |
| Wind and dust | |
| High Wind Warning | 1 |
| High Wind Watch | 1 |
| Wind Advisory | 13 |
| Fire | |
| Red Flag Warning | 3 |
| Fog and smoke | |
| Dense Fog Advisory | 5 |
| Tropical | |
| Tropical Storm Warning | 1 |
| Coast and beach | |
| Coastal Flood Watch | 1 |
| Coastal Flood Advisory | 9 |
| High Surf Advisory | 1 |
| Coastal Flood Statement | 13 |
| Rip Current Statement | 7 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20202022
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.