Alert archive / Massachusetts / Bristol County
Weather alerts in Bristol County, Massachusetts, 2020
175 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Bristol County and its neighbors
Each county as a circle sized by its count in 2020. Tap one for its archive.
- Alerts
- 175
- Warnings
- 54
- Watches
- 17
- Advisories
- 57
- Busiest month
- August33 alerts
- Busiest day
- June 28, 20209 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Bristol County, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 35 | 31 | 11% | 14 | 93% | 29 min |
| Flash flood warnings | 4 | 0 | 100% | 1 | 0% |
Each office's whole area, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Boston/Norton, MA: tornado warnings | 8 | 1 | 88% | 2 | 50% | 5 min |
| NWS Boston/Norton, MA: severe thunderstorm warnings | 152 | 115 | 24% | 525 | 85% | 26 min |
| NWS Boston/Norton, MA: flash flood warnings | 16 | 2 | 88% | 5 | 60% | 16 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 7, 11:31 AM EST | Winter Weather Advisory | BOX | 17 hr |
| Jan 7, 3:58 PM EST | Wind Advisory | BOX | 31 hr |
| Jan 8, 3:59 PM EST | Special Weather Statement | BOX | 61 min |
| Jan 11, 1:08 PM EST | Wind Advisory | BOX | 27 hr |
| Jan 15, 3:47 PM EST | Wind Advisory | BOX | 36 hr |
| Jan 17, 3:58 PM EST | Winter Weather Advisory | BOX | 38 hr |
| Feb 5, 3:35 AM EST | Winter Weather Advisory | BOX | 61 hr |
| Feb 6, 3:23 PM EST | High Wind Warning | BOX | 30 hr |
| Feb 6, 3:23 PM EST | Wind Advisory | BOX | 30 hr |
| Feb 26, 4:24 PM EST | Wind Advisory | BOX | 32 hr |
| Mar 29, 12:30 PM EDT | Special Weather Statement | BOX | 45 min |
| Mar 29, 8:39 PM EDT | Special Weather Statement | BOX | 51 min |
| Mar 29, 8:52 PM EDT | Severe Thunderstorm Warning | BOX | 38 min |
| Mar 29, 9:02 PM EDT | Special Weather Statement | BOX | 43 min |
| Mar 29, 9:44 PM EDT | Special Weather Statement | BOX | 31 min |
| Mar 29, 9:52 PM EDT | Severe Thunderstorm Warning | BOX | 38 min |
| Mar 29, 10:13 PM EDT | Severe Thunderstorm Warning | BOX | 19 min |
| Apr 9, 4:10 AM EDT | Wind Advisory | BOX | 18 hr |
| Apr 9, 12:38 PM EDT | Special Weather Statement | BOX | 52 min |
| Apr 9, 2:49 PM EDT | Special Weather Statement | BOX | 41 min |
| Apr 9, 3:32 PM EDT | Severe Thunderstorm Warning | BOX | 58 min |
| Apr 11, 3:29 PM EDT | High Wind Watch | BOX | 25 hr |
| Apr 12, 4:07 PM EDT | High Wind Warning | BOX | 28 hr |
| Apr 17, 3:51 AM EDT | Winter Weather Advisory | BOX | 30 hr |
| Apr 20, 3:36 PM EDT | Frost Advisory | BOX | 16 hr |
| Apr 20, 3:36 PM EDT | Wind Advisory | BOX | 28 hr |
| Apr 21, 10:27 AM EDT | Special Weather Statement | BOX | 48 min |
| Apr 21, 5:18 PM EDT | Special Weather Statement | BOX | 42 min |
| Apr 22, 10:33 AM EDT | Wind Advisory | BOX | 8 hr |
| May 6, 3:41 PM EDT | Coastal Flood Advisory | BOX | 35 hr |
| May 8, 1:45 PM EDT | Coastal Flood Statement | BOX | 10 hr |
| May 8, 3:42 PM EDT | Wind Advisory | BOX | 34 hr |
| May 9, 3:37 AM EDT | Freeze Warning | BOX | 27 hr |
| May 9, 9:24 PM EDT | Special Weather Statement | BOX | 51 min |
| May 12, 1:14 PM EDT | Frost Advisory | BOX | 19 hr |
| May 15, 8:59 PM EDT | Severe Thunderstorm Warning | BOX | 61 min |
| May 15, 9:09 PM EDT | Mesoscale Discussion | SPC | 66 min |
| May 25, 9:16 PM EDT | Dense Fog Advisory | BOX | 11 hr |
| May 26, 2:21 PM EDT | Dense Fog Advisory | BOX | 18 hr |
| May 27, 4:07 PM EDT | Dense Fog Advisory | BOX | 15 hr |
| May 28, 10:13 PM EDT | Dense Fog Advisory | BOX | 14 hr |
| Jun 4, 3:30 AM EDT | Rip Current Statement | BOX | 15 hr |
| Jun 6, 12:23 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 6, 2:51 PM EDT | Severe Thunderstorm Warning | BOX | 54 min |
| Jun 6, 3:29 PM EDT | Severe Thunderstorm Warning | BOX | 61 min |
| Jun 6, 4:01 PM EDT | Special Weather Statement | BOX | 59 min |
| Jun 6, 4:43 PM EDT | Special Weather Statement | BOX | 47 min |
| Jun 10, 4:10 PM EDT | Dense Fog Advisory | BOX | 12 hr |
| Jun 11, 3:54 AM EDT | High Surf Advisory | BOX | 16 hr |
| Jun 23, 7:10 PM EDT | Dense Fog Advisory | BOX | 8 hr |
| Jun 26, 11:49 AM EDT | Special Weather Statement | BOX | 41 min |
| Jun 28, 12:37 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Jun 28, 1:32 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 28, 4:08 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 28, 4:58 PM EDT | Severe Thunderstorm Warning | BOX | 62 min |
| Jun 28, 5:04 PM EDT | Flash Flood Warning | BOX | 116 min |
| Jun 28, 6:04 PM EDT | Severe Thunderstorm Warning | BOX | 56 min |
| Jun 28, 6:56 PM EDT | Areal Flood Warning | BOX | 2 hr |
| Jun 28, 7:01 PM EDT | Special Weather Statement | BOX | 44 min |
| Jun 28, 7:20 PM EDT | Mesoscale Discussion | SPC | 55 min |
| Jun 29, 1:01 PM EDT | Special Weather Statement | BOX | 59 min |
| Jun 29, 2:48 PM EDT | Mesoscale Discussion | SPC | 117 min |
| Jul 1, 4:20 PM EDT | Special Weather Statement | BOX | 40 min |
| Jul 2, 2:19 AM EDT | Dense Fog Advisory | BOX | 7 hr |
| Jul 2, 6:30 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 2, 9:09 PM EDT | Severe Thunderstorm Warning | BOX | 47 min |
| Jul 5, 10:25 PM EDT | Severe Thunderstorm Warning | BOX | 65 min |
| Jul 5, 11:00 PM EDT | Severe Thunderstorm Warning | BOX | 60 min |
| Jul 5, 11:38 PM EDT | Special Weather Statement | BOX | 52 min |
| Jul 9, 4:06 PM EDT | Flash Flood Watch | BOX | 29 hr |
| Jul 11, 3:19 AM EDT | High Surf Advisory | BOX | 15 hr |
| Jul 11, 7:02 PM EDT | High Surf Advisory | BOX | 25 hr |
| Jul 12, 3:34 AM EDT | Heat Advisory | BOX | 14 hr |
| Jul 13, 12:54 PM EDT | Mesoscale Discussion | SPC | 96 min |
| Jul 13, 6:01 PM EDT | Special Weather Statement | BOX | 44 min |
| Jul 14, 12:11 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 14, 1:46 PM EDT | Severe Thunderstorm Warning | BOX | 59 min |
| Jul 14, 2:24 PM EDT | Flash Flood Warning | BOX | 100 min |
| Jul 14, 2:37 PM EDT | Severe Thunderstorm Warning | BOX | 68 min |
| Jul 14, 6:41 PM EDT | Special Weather Statement | BOX | 49 min |
| Jul 18, 3:23 AM EDT | Heat Advisory | BOX | 65 hr |
| Jul 18, 4:22 AM EDT | Dense Fog Advisory | BOX | 4 hr |
| Jul 23, 12:58 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 23, 4:38 PM EDT | Severe Thunderstorm Warning | BOX | 67 min |
| Jul 23, 6:48 PM EDT | Mesoscale Discussion | SPC | 57 min |
| Jul 26, 3:47 AM EDT | Excessive Heat Watch | BOX | 11 hr |
| Jul 26, 3:05 PM EDT | Heat Advisory | BOX | 52 hr |
| Jul 28, 10:25 AM EDT | Excessive Heat Warning | BOX | 9 hr |
| Jul 28, 3:34 PM EDT | Special Weather Statement | BOX | 41 min |
| Jul 30, 1:20 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Aug 3, 5:18 AM EDT | Tropical Storm Watch | BOX | 8 hr |
| Aug 3, 11:11 AM EDT | Tropical Storm Warning | BOX | 36 hr |
| Aug 4, 3:24 AM EDT | Coastal Flood Advisory | BOX | 17 hr |
| Aug 4, 11:34 AM EDT | Mesoscale Discussion | SPC | 86 min |
| Aug 4, 12:43 PM EDT | Tornado Watch | SPC | 6 hr |
| Aug 4, 3:05 PM EDT | Mesoscale Discussion | SPC | 85 min |
| Aug 4, 11:06 PM EDT | High Surf Advisory | BOX | 19 hr |
| Aug 9, 3:35 PM EDT | Heat Advisory | BOX | 3 days |
| Aug 19, 5:28 PM EDT | Severe Thunderstorm Warning | BOX | 38 min |
| Aug 22, 12:15 PM EDT | Severe Thunderstorm Warning | BOX | 45 min |
| Aug 22, 12:50 PM EDT | Severe Thunderstorm Warning | BOX | 40 min |
| Aug 22, 2:03 PM EDT | Severe Thunderstorm Warning | BOX | 42 min |
| Aug 22, 3:14 PM EDT | Severe Thunderstorm Warning | BOX | 61 min |
| Aug 22, 3:50 PM EDT | Severe Thunderstorm Warning | BOX | 55 min |
| Aug 22, 4:30 PM EDT | Severe Thunderstorm Warning | BOX | 47 min |
| Aug 22, 5:09 PM EDT | Severe Thunderstorm Warning | BOX | 50 min |
| Aug 22, 5:51 PM EDT | Severe Thunderstorm Warning | BOX | 19 min |
| Aug 23, 5:38 PM EDT | Severe Thunderstorm Warning | BOX | 52 min |
| Aug 23, 6:10 PM EDT | Severe Thunderstorm Warning | BOX | 49 min |
| Aug 23, 6:20 PM EDT | Severe Thunderstorm Warning | BOX | 40 min |
| Aug 23, 6:26 PM EDT | Flash Flood Warning | BOX | 2 hr |
| Aug 23, 6:39 PM EDT | Areal Flood Warning | BOX | 2 hr |
| Aug 24, 1:23 PM EDT | Special Weather Statement | BOX | 52 min |
| Aug 24, 1:43 PM EDT | Severe Thunderstorm Warning | BOX | 62 min |
| Aug 24, 2:00 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 24, 2:42 PM EDT | Flash Flood Warning | BOX | 2 hr |
| Aug 24, 3:10 PM EDT | Special Weather Statement | BOX | 50 min |
| Aug 24, 3:30 PM EDT | Special Weather Statement | BOX | 45 min |
| Aug 25, 3:12 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 25, 6:11 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 25, 6:58 PM EDT | Severe Thunderstorm Warning | BOX | 32 min |
| Aug 27, 2:24 PM EDT | Severe Thunderstorm Warning | BOX | 36 min |
| Aug 27, 3:03 PM EDT | Special Weather Statement | BOX | 42 min |
| Sep 8, 3:16 AM EDT | Dense Fog Advisory | BOX | 5 hr |
| Sep 10, 1:42 AM EDT | Dense Fog Advisory | BOX | 8 hr |
| Sep 13, 3:55 PM EDT | High Surf Advisory | BOX | 52 hr |
| Sep 19, 3:58 AM EDT | High Surf Advisory | BOX | 5 days |
| Sep 19, 3:12 PM EDT | Frost Advisory | BOX | 17 hr |
| Sep 20, 3:57 PM EDT | Frost Advisory | BOX | 16 hr |
| Sep 21, 3:47 PM EDT | Frost Advisory | BOX | 16 hr |
| Sep 21, 3:48 PM EDT | Fire Weather Watch | BOX | 11 hr |
| Sep 22, 3:10 AM EDT | Red Flag Warning | BOX | 16 hr |
| Sep 28, 9:06 PM EDT | Dense Fog Advisory | BOX | 13 hr |
| Sep 29, 4:01 AM EDT | Wind Advisory | BOX | 33 hr |
| Sep 30, 1:12 AM EDT | High Wind Warning | BOX | 9 hr |
| Sep 30, 5:09 AM EDT | Mesoscale Discussion | SPC | 96 min |
| Oct 6, 3:22 PM EDT | High Wind Watch | BOX | 12 hr |
| Oct 6, 3:22 PM EDT | Wind Advisory | BOX | 30 hr |
| Oct 7, 5:20 PM EDT | Mesoscale Discussion | SPC | 85 min |
| Oct 7, 5:38 PM EDT | Severe Thunderstorm Warning | BOX | 40 min |
| Oct 7, 6:03 PM EDT | Severe Thunderstorm Warning | BOX | 42 min |
| Oct 7, 6:36 PM EDT | Severe Thunderstorm Warning | BOX | 39 min |
| Oct 8, 3:21 AM EDT | Frost Advisory | BOX | 29 hr |
| Oct 9, 3:58 PM EDT | Wind Advisory | BOX | 27 hr |
| Oct 9, 4:14 PM EDT | Fire Weather Watch | BOX | 12 hr |
| Oct 10, 3:49 AM EDT | Red Flag Warning | BOX | 16 hr |
| Oct 17, 3:37 AM EDT | Frost Advisory | BOX | 29 hr |
| Oct 20, 11:17 PM EDT | Dense Fog Advisory | BOX | 13 hr |
| Oct 21, 6:16 PM EDT | Dense Fog Advisory | BOX | 15 hr |
| Oct 23, 2:35 AM EDT | Dense Fog Advisory | BOX | 4 hr |
| Nov 1, 3:07 PM EST | Wind Advisory | BOX | 43 hr |
| Nov 10, 2:57 AM EST | Dense Fog Advisory | BOX | 6 hr |
| Nov 14, 3:39 PM EST | Wind Advisory | BOX | 33 hr |
| Nov 15, 7:01 PM EST | Mesoscale Discussion | SPC | 59 min |
| Nov 15, 7:32 PM EST | Severe Thunderstorm Watch | SPC | 5 hr |
| Nov 15, 9:37 PM EST | Mesoscale Discussion | SPC | 113 min |
| Nov 15, 10:22 PM EST | Severe Thunderstorm Warning | BOX | 53 min |
| Nov 15, 10:24 PM EST | Severe Thunderstorm Warning | BOX | 66 min |
| Nov 29, 2:42 AM EST | High Wind Watch | BOX | 25 hr |
| Nov 30, 3:29 AM EST | High Wind Warning | BOX | 19 hr |
| Nov 30, 3:03 PM EST | Coastal Flood Statement | BOX | 7 hr |
| Nov 30, 7:13 PM EST | Mesoscale Discussion | SPC | 2 hr |
| Nov 30, 10:15 PM EST | Wind Advisory | BOX | 6 hr |
| Dec 5, 2:48 AM EST | Winter Weather Advisory | BOX | 17 hr |
| Dec 5, 2:52 AM EST | Wind Advisory | BOX | 21 hr |
| Dec 14, 3:45 PM EST | Winter Storm Watch | BOX | 36 hr |
| Dec 15, 3:14 PM EST | Winter Storm Warning | BOX | 46 hr |
| Dec 21, 12:21 AM EST | Dense Fog Advisory | BOX | 7 hr |
| Dec 22, 3:28 PM EST | High Wind Watch | BOX | 23 hr |
| Dec 23, 2:05 PM EST | Flood Watch | BOX | 51 hr |
| Dec 23, 2:30 PM EST | High Wind Warning | BOX | 45 hr |
| Dec 24, 1:45 PM EST | Coastal Flood Advisory | BOX | 19 hr |
| Dec 25, 8:19 AM EST | Special Weather Statement | BOX | 56 min |
| Dec 25, 8:49 AM EST | Areal Flood Warning | BOX | 5 hr |
| Dec 25, 1:37 PM EST | Areal Flood Warning | BOX | 5 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20192021
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.