Alert archive / Massachusetts / Middlesex County
Weather alerts in Middlesex County, Massachusetts, 2021
185 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Middlesex County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 185
- Warnings
- 76
- Watches
- 18
- Advisories
- 40
- Busiest month
- July48 alerts
- Busiest day
- August 19, 202111 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
4 of 6 tornado warnings covering Middlesex County in 2021 had a tornado report inside them; 2 of 3 tornado reports fell inside a warning, on average 3 minutes after it went out.
Middlesex County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 6 | 4 | 33% | 3 | 67% | 3 min |
| Severe thunderstorm warnings | 39 | 24 | 38% | 26 | 88% | 30 min |
| Flash flood warnings | 8 | 0 | 100% | 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 16, 3:03 AM EST | Wind Advisory | BOX | 9 hr |
| Jan 23, 6:43 AM EST | Special Weather Statement | BOX | 62 min |
| Jan 25, 3:02 PM EST | Winter Weather Advisory | BOX | 37 hr |
| Jan 28, 3:32 AM EST | Wind Chill Advisory | BOX | 32 hr |
| Jan 29, 3:10 PM EST | Wind Chill Advisory | BOX | 19 hr |
| Jan 30, 3:28 PM EST | Winter Storm Watch | BOX | 24 hr |
| Jan 31, 3:37 PM EST | Winter Storm Warning | BOX | 37 hr |
| Feb 1, 1:43 PM EST | Mesoscale Discussion | SPC | 6 hr |
| Feb 1, 7:27 PM EST | Mesoscale Discussion | SPC | 6 hr |
| Feb 2, 4:07 AM EST | Winter Weather Advisory | BOX | 11 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, 3:11 AM EST | Wind Chill Advisory | BOX | 30 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 14, 4:19 PM EDT | Special Weather Statement | BOX | 56 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 |
| Mar 28, 2:45 PM EDT | High Wind Warning | BOX | 24 hr |
| Apr 15, 3:37 AM EDT | Winter Storm Watch | BOX | 12 hr |
| Apr 15, 3:37 AM EDT | Winter Storm Warning | BOX | 40 hr |
| Apr 15, 3:37 AM EDT | Winter Weather Advisory | BOX | 40 hr |
| Apr 21, 2:56 PM EDT | Mesoscale Discussion | SPC | 94 min |
| Apr 29, 3:24 PM EDT | Wind Advisory | BOX | 35 hr |
| May 16, 5:30 PM EDT | Special Weather Statement | BOX | 45 min |
| May 23, 1:20 PM EDT | Mesoscale Discussion | SPC | 115 min |
| May 26, 3:21 PM EDT | Mesoscale Discussion | SPC | 54 min |
| May 26, 3:56 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| May 26, 6:07 PM EDT | Mesoscale Discussion | SPC | 113 min |
| May 26, 6:13 PM EDT | Severe Thunderstorm Warning | BOX | 62 min |
| May 26, 7:15 PM EDT | Special Weather Statement | BOX | 45 min |
| Jun 6, 3:29 AM EDT | Heat Advisory | BOX | 64 hr |
| Jun 8, 12:54 PM EDT | Flash Flood Watch | BOX | 8 hr |
| Jun 8, 5:17 PM EDT | Severe Thunderstorm Warning | BOX | 58 min |
| Jun 9, 3:12 AM EDT | Heat Advisory | BOX | 17 hr |
| Jun 9, 3:19 PM EDT | Mesoscale Discussion | SPC | 116 min |
| Jun 15, 2:38 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 26, 3:15 PM EDT | Heat Advisory | BOX | 4 days |
| Jun 29, 7:17 PM EDT | Mesoscale Discussion | SPC | 88 min |
| 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, 4:32 PM EDT | Severe Thunderstorm Warning | BOX | 58 min |
| Jun 30, 4:48 PM EDT | Mesoscale Discussion | SPC | 87 min |
| Jun 30, 5:00 PM EDT | Severe Thunderstorm Warning | BOX | 30 min |
| Jun 30, 5:13 PM EDT | Severe Thunderstorm Warning | BOX | 62 min |
| Jun 30, 5:25 PM EDT | Severe Thunderstorm Warning | BOX | 49 min |
| Jun 30, 5:43 PM EDT | Severe Thunderstorm Warning | BOX | 51 min |
| Jun 30, 5:54 PM EDT | Severe Thunderstorm Warning | BOX | 53 min |
| Jun 30, 6:12 PM EDT | Severe Thunderstorm Warning | BOX | 47 min |
| Jul 1, 10:17 PM EDT | Special Weather Statement | BOX | 88 min |
| Jul 2, 12:05 AM EDT | Special Weather Statement | BOX | 55 min |
| Jul 2, 1:00 AM EDT | Special Weather Statement | BOX | 90 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 3, 11:06 PM EDT | Special Weather Statement | BOX | 54 min |
| 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, 4:23 PM EDT | Mesoscale Discussion | SPC | 97 min |
| Jul 6, 4:42 PM EDT | Special Weather Statement | BOX | 48 min |
| Jul 6, 5:13 PM EDT | Severe Thunderstorm Warning | BOX | 62 min |
| Jul 6, 5:21 PM EDT | Severe Thunderstorm Warning | BOX | 42 min |
| Jul 6, 5:52 PM EDT | Severe Thunderstorm Warning | BOX | 53 min |
| Jul 6, 6:13 PM EDT | Severe Thunderstorm Warning | BOX | 31 min |
| Jul 7, 1:50 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Jul 7, 2:41 PM EDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jul 7, 4:33 PM EDT | Severe Thunderstorm Warning | BOX | 57 min |
| Jul 7, 4:48 PM EDT | Mesoscale Discussion | SPC | 87 min |
| Jul 7, 6:17 PM EDT | Severe Thunderstorm Warning | BOX | 58 min |
| Jul 7, 6:18 PM EDT | Severe Thunderstorm Warning | BOX | 36 min |
| Jul 7, 6:59 PM EDT | Severe Thunderstorm Warning | BOX | 61 min |
| Jul 7, 7:11 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| 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, 9:11 AM EDT | Flash Flood Warning | BOX | 7 hr |
| Jul 9, 9:32 AM EDT | Flash Flood Warning | BOX | 6 hr |
| Jul 9, 12:19 PM EDT | River Flood Warning | BOX | 37 hr |
| Jul 9, 3:24 PM EDT | Areal Flood Warning | BOX | 5 hr |
| Jul 9, 3:41 PM EDT | Areal Flood Warning | BOX | 5 hr |
| Jul 10, 12:37 PM EDT | River Flood Warning | BOX | 24 hr |
| Jul 11, 3:34 PM EDT | Flash Flood Watch | BOX | 21 hr |
| Jul 12, 8:09 AM EDT | River Flood Warning | BOX | 21 days |
| Jul 14, 12:32 AM EDT | Dense Fog Advisory | BOX | 9 hr |
| Jul 16, 9:38 AM EDT | Heat Advisory | BOX | 9 hr |
| Jul 16, 4:36 PM EDT | Severe Thunderstorm Warning | BOX | 35 min |
| Jul 16, 5:47 PM EDT | Severe Thunderstorm Warning | BOX | 33 min |
| Jul 17, 4:34 PM EDT | Severe Thunderstorm Warning | BOX | 36 min |
| Jul 17, 5:10 PM EDT | Severe Thunderstorm Warning | BOX | 65 min |
| Jul 23, 2:28 PM EDT | Special Weather Statement | BOX | 32 min |
| Jul 23, 3:28 PM EDT | Severe Thunderstorm Warning | BOX | 47 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, 4:36 PM EDT | Mesoscale Discussion | SPC | 84 min |
| 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, 7:26 PM EDT | Severe Thunderstorm Warning | BOX | 64 min |
| Jul 29, 11:19 PM 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 11, 4:57 PM EDT | Mesoscale Discussion | SPC | 93 min |
| Aug 12, 2:53 PM EDT | Heat Advisory | BOX | 29 hr |
| Aug 12, 3:50 PM EDT | Mesoscale Discussion | SPC | 55 min |
| Aug 12, 6:13 PM EDT | Severe Thunderstorm Warning | BOX | 62 min |
| Aug 12, 6:44 PM EDT | Mesoscale Discussion | SPC | 61 min |
| Aug 19, 10:14 AM EDT | Severe Thunderstorm Warning | BOX | 44 min |
| Aug 19, 10:21 AM EDT | Tornado Warning | BOX | 29 min |
| Aug 19, 10:46 AM EDT | Flash Flood Warning | BOX | 3 hr |
| Aug 19, 10:49 AM EDT | Mesoscale Discussion | SPC | 86 min |
| 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, 1:18 PM EDT | Tornado Warning | BOX | 27 min |
| Aug 19, 1:54 PM EDT | Special Weather Statement | BOX | 51 min |
| Aug 19, 2:23 PM EDT | Severe Thunderstorm Warning | BOX | 37 min |
| Aug 23, 11:30 AM EDT | Special Weather Statement | BOX | 45 min |
| Aug 23, 11:45 AM EDT | Tornado Warning | BOX | 45 min |
| Aug 23, 12:26 PM EDT | Tornado Warning | BOX | 43 min |
| Aug 23, 1:35 PM EDT | Tornado Warning | BOX | 40 min |
| Aug 23, 4:15 PM EDT | Special Weather Statement | BOX | 45 min |
| Aug 23, 5:19 PM EDT | Special Weather Statement | BOX | 41 min |
| 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, 10:01 PM EDT | Flash Flood Warning | BOX | 8 hr |
| Sep 1, 10:57 PM EDT | Flash Flood Warning | BOX | 8 hr |
| Sep 1, 11:02 PM EDT | Flash Flood Warning | BOX | 8 hr |
| Sep 2, 5:30 AM EDT | River Flood Warning | BOX | 22 hr |
| Sep 2, 6:02 AM EDT | Flash Flood Warning | BOX | 3 hr |
| Sep 2, 6:50 AM EDT | Areal Flood Warning | BOX | 6 hr |
| Sep 2, 7:04 AM EDT | Areal Flood Warning | BOX | 11 hr |
| Sep 2, 8:20 AM EDT | River Flood Warning | BOX | 60 hr |
| Sep 2, 12:51 PM EDT | Areal Flood Warning | BOX | 6 hr |
| Sep 2, 5:59 PM EDT | River Flood Warning | BOX | 25 hr |
| Sep 9, 4:12 AM EDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 13, 3:14 AM EDT | Severe Thunderstorm Warning | BOX | 31 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 15, 7:40 PM EDT | Special Weather Statement | BOX | 50 min |
| Sep 15, 7:53 PM EDT | Severe Thunderstorm Warning | BOX | 13 min |
| Sep 17, 8:10 PM EDT | Dense Fog Advisory | BOX | 12 hr |
| Sep 18, 8:28 PM EDT | Special Weather Statement | BOX | 62 min |
| Sep 24, 11:11 AM EDT | Severe Thunderstorm Warning | BOX | 22 min |
| Sep 28, 9:29 AM EDT | Severe Thunderstorm Warning | BOX | 61 min |
| Sep 28, 10:02 AM EDT | Severe Thunderstorm Warning | BOX | 43 min |
| 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 |
| Nov 5, 4:03 PM EDT | Coastal Flood Statement | BOX | 23 hr |
| Nov 12, 3:20 PM EST | Special Weather Statement | BOX | 40 min |
| Nov 13, 5:17 PM EST | Severe Thunderstorm Warning | BOX | 7 min |
| Nov 13, 5:26 PM EST | Severe Thunderstorm Warning | BOX | 32 min |
| Nov 13, 5:55 PM EST | Severe Thunderstorm Warning | BOX | 25 min |
| Dec 2, 5:06 AM EST | Winter Weather Advisory | BOX | 3 hr |
| Dec 6, 9:02 PM EST | Special Weather Statement | BOX | 58 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 10, 10:03 PM EST | Winter Weather Advisory | BOX | 11 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, 4:26 AM EST | Mesoscale Discussion | SPC | 4 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 27, 3:14 AM EST | Winter Weather Advisory | BOX | 30 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 | 39 |
| Tornado Warning | 6 |
| Severe Thunderstorm Watch | 5 |
| Mesoscale Discussion | 28 |
| Special Weather Statement | 22 |
| Flooding | |
| Areal Flood Warning | 6 |
| Flash Flood Warning | 8 |
| River Flood Warning | 6 |
| Flash Flood Watch | 5 |
| Flood Watch | 1 |
| Winter | |
| Winter Storm Warning | 4 |
| Winter Storm Watch | 5 |
| Winter Weather Advisory | 14 |
| Heat | |
| Excessive Heat Warning | 1 |
| Excessive Heat Watch | 1 |
| Heat Advisory | 8 |
| Cold | |
| Frost Advisory | 1 |
| Wind Chill Advisory | 3 |
| Wind and dust | |
| High Wind Warning | 2 |
| High Wind Watch | 1 |
| Wind Advisory | 9 |
| Fire | |
| Red Flag Warning | 3 |
| Fog and smoke | |
| Dense Fog Advisory | 5 |
| Tropical | |
| Tropical Storm Warning | 1 |
| Coast and beach | |
| Coastal Flood Statement | 1 |
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.