Alert archive / Massachusetts / Norfolk County
Weather alerts in Norfolk County, Massachusetts, 2019
188 weather alerts in 2019, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Norfolk County and its neighbors
Each county as a circle sized by its count in 2019. Tap one for its archive.
- Alerts
- 188
- Warnings
- 50
- Watches
- 23
- Advisories
- 62
- Busiest month
- July35 alerts
- Busiest day
- July 17, 201914 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Norfolk County, 2019
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 26 | 20 | 23% | 14 | 50% | 25 min |
| Flash flood warnings | 2 | 0 | 100% | 0 |
Each office's whole area, 2019
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Boston/Norton, MA: tornado warnings | 13 | 2 | 85% | 7 | 86% | 23 min |
| NWS Boston/Norton, MA: severe thunderstorm warnings | 120 | 68 | 43% | 336 | 63% | 23 min |
| NWS Boston/Norton, MA: flash flood warnings | 12 | 1 | 92% | 1 | 100% | 47 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 8, 6:01 PM EST | Dense Fog Advisory | BOX | 10 hr |
| Jan 9, 4:17 AM EST | Dense Fog Advisory | BOX | 3 hr |
| Jan 9, 4:17 AM EST | Wind Advisory | BOX | 12 hr |
| Jan 17, 4:10 AM EST | Winter Storm Watch | BOX | 48 hr |
| Jan 17, 1:53 PM EST | Coastal Flood Watch | BOX | 25 hr |
| Jan 18, 3:02 PM EST | Coastal Flood Warning | BOX | 25 hr |
| Jan 18, 3:02 PM EST | Coastal Flood Advisory | BOX | 45 hr |
| Jan 19, 4:29 AM EST | Winter Weather Advisory | BOX | 39 hr |
| Jan 19, 3:34 PM EST | Flood Watch | BOX | 24 hr |
| Jan 20, 4:20 AM EST | Wind Chill Advisory | BOX | 54 hr |
| Jan 20, 1:01 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Jan 20, 3:20 PM EST | Coastal Flood Statement | BOX | 21 hr |
| Jan 23, 3:50 AM EST | Flash Flood Watch | BOX | 39 hr |
| Jan 23, 3:53 AM EST | High Wind Watch | BOX | 11 hr |
| Jan 23, 3:08 PM EST | High Wind Warning | BOX | 26 hr |
| Jan 23, 3:08 PM EST | Wind Advisory | BOX | 26 hr |
| Jan 24, 12:58 PM EST | Areal Flood Advisory | BOX | 4 hr |
| Jan 24, 3:27 PM EST | Areal Flood Warning | BOX | 6 hr |
| Jan 24, 5:07 PM EST | Wind Advisory | BOX | 113 min |
| Jan 25, 4:32 AM EST | Areal Flood Warning | BOX | 2 hr |
| Jan 30, 3:21 AM EST | Wind Advisory | BOX | 18 hr |
| Jan 30, 3:29 AM EST | Wind Chill Advisory | BOX | 30 hr |
| Jan 30, 5:58 PM EST | Snow Squall Warning | BOX | 47 min |
| Jan 30, 6:36 PM EST | Snow Squall Warning | BOX | 39 min |
| Jan 30, 7:10 PM EST | Snow Squall Warning | BOX | 50 min |
| Feb 5, 3:16 PM EST | Winter Weather Advisory | BOX | 36 hr |
| Feb 8, 3:29 AM EST | Wind Advisory | BOX | 35 hr |
| Feb 10, 3:49 PM EST | Winter Storm Watch | BOX | 35 hr |
| Feb 11, 4:01 AM EST | Winter Weather Advisory | BOX | 51 hr |
| Feb 12, 12:29 PM EST | Special Weather Statement | BOX | 2 hr |
| Feb 13, 8:42 PM EST | Special Weather Statement | BOX | 63 min |
| Feb 13, 8:59 PM EST | Snow Squall Warning | BOX | 46 min |
| Feb 17, 3:48 AM EST | Winter Storm Watch | BOX | 12 hr |
| Feb 17, 3:48 AM EST | Winter Weather Advisory | BOX | 35 hr |
| Feb 17, 3:30 PM EST | Winter Storm Warning | BOX | 23 hr |
| Feb 19, 3:38 PM EST | Winter Weather Advisory | BOX | 39 hr |
| Feb 20, 4:01 PM EST | Coastal Flood Statement | BOX | 23 hr |
| Feb 20, 10:15 PM EST | Mesoscale Discussion | SPC | 5 hr |
| Feb 23, 3:35 AM EST | Winter Weather Advisory | BOX | 30 hr |
| Feb 23, 3:37 AM EST | High Wind Watch | BOX | 25 hr |
| Feb 24, 4:07 AM EST | High Wind Warning | BOX | 39 hr |
| Feb 25, 7:01 PM EST | Wind Advisory | BOX | 20 hr |
| Feb 26, 3:34 PM EST | Winter Weather Advisory | BOX | 42 hr |
| Mar 1, 3:15 AM EST | Winter Weather Advisory | BOX | 34 hr |
| Mar 1, 1:51 PM EST | Winter Storm Warning | BOX | 17 hr |
| Mar 2, 4:09 AM EST | Winter Storm Watch | BOX | 23 hr |
| Mar 3, 3:18 AM EST | Winter Storm Warning | BOX | 31 hr |
| Mar 3, 10:44 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Mar 4, 3:16 AM EST | Mesoscale Discussion | SPC | 4 hr |
| Mar 15, 11:24 AM EDT | Special Weather Statement | BOX | 66 min |
| Mar 21, 2:37 PM EDT | Coastal Flood Advisory | BOX | 24 hr |
| Apr 2, 2:54 PM EDT | Wind Advisory | BOX | 30 hr |
| Apr 3, 2:59 PM EDT | Fire Weather Watch | BOX | 13 hr |
| Apr 4, 4:12 AM EDT | Red Flag Warning | BOX | 15 hr |
| Apr 14, 3:00 AM EDT | Wind Advisory | BOX | 49 hr |
| Apr 15, 6:25 AM EDT | Areal Flood Advisory | BOX | 110 min |
| Apr 15, 7:14 AM EDT | Areal Flood Advisory | BOX | 2 hr |
| Apr 19, 1:48 PM EDT | Wind Advisory | BOX | 6 hr |
| Apr 22, 5:10 PM EDT | Areal Flood Advisory | BOX | 2 hr |
| Apr 28, 3:13 PM EDT | Frost Advisory | BOX | 16 hr |
| May 7, 3:50 AM EDT | Frost Advisory | BOX | 4 hr |
| May 13, 4:36 PM EDT | Coastal Flood Statement | BOX | 17 hr |
| May 20, 1:26 AM EDT | Severe Thunderstorm Warning | BOX | 19 min |
| May 20, 1:01 PM EDT | Mesoscale Discussion | SPC | 119 min |
| May 20, 4:17 PM EDT | Special Weather Statement | BOX | 28 min |
| May 20, 5:16 PM EDT | Mesoscale Discussion | SPC | 119 min |
| May 20, 5:48 PM EDT | Severe Thunderstorm Warning | BOX | 27 min |
| May 24, 8:44 AM EDT | Wind Advisory | BOX | 12 hr |
| Jun 1, 4:10 AM EDT | Dense Fog Advisory | BOX | 5 hr |
| Jun 1, 11:12 PM EDT | Dense Fog Advisory | BOX | 9 hr |
| Jun 22, 1:53 PM EDT | Special Weather Statement | BOX | 52 min |
| Jun 29, 5:54 AM EDT | Severe Thunderstorm Warning | BOX | 19 min |
| Jun 29, 3:35 PM EDT | Severe Thunderstorm Warning | BOX | 55 min |
| Jun 29, 4:08 PM EDT | Severe Thunderstorm Warning | BOX | 52 min |
| Jun 29, 4:24 PM EDT | Areal Flood Warning | BOX | 55 min |
| Jun 30, 12:59 AM EDT | Special Weather Statement | BOX | 46 min |
| Jun 30, 1:43 PM EDT | Severe Thunderstorm Warning | BOX | 47 min |
| Jun 30, 2:37 PM EDT | Severe Thunderstorm Warning | BOX | 53 min |
| Jun 30, 5:46 PM EDT | Special Weather Statement | BOX | 44 min |
| Jun 30, 6:51 PM EDT | Special Weather Statement | BOX | 39 min |
| Jul 6, 3:39 AM EDT | Heat Advisory | BOX | 13 hr |
| Jul 6, 1:48 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 6, 5:05 PM EDT | Severe Thunderstorm Warning | BOX | 40 min |
| Jul 6, 5:36 PM EDT | Special Weather Statement | BOX | 84 min |
| Jul 6, 5:59 PM EDT | Areal Flood Warning | BOX | 2 hr |
| Jul 12, 3:46 AM EDT | Special Weather Statement | BOX | 59 min |
| Jul 17, 1:03 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 17, 1:24 PM EDT | Flash Flood Watch | BOX | 7 hr |
| Jul 17, 1:58 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 17, 2:59 PM EDT | Severe Thunderstorm Warning | BOX | 61 min |
| Jul 17, 3:53 PM EDT | Severe Thunderstorm Warning | BOX | 67 min |
| Jul 17, 3:59 PM EDT | Severe Thunderstorm Warning | BOX | 61 min |
| Jul 17, 3:59 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 17, 4:03 PM EDT | Flash Flood Warning | BOX | 117 min |
| Jul 17, 4:38 PM EDT | Severe Thunderstorm Warning | BOX | 52 min |
| Jul 17, 5:04 PM EDT | Severe Thunderstorm Warning | BOX | 41 min |
| Jul 17, 5:19 PM EDT | Severe Thunderstorm Warning | BOX | 41 min |
| Jul 17, 5:34 PM EDT | Severe Thunderstorm Warning | BOX | 26 min |
| Jul 17, 5:38 PM EDT | Severe Thunderstorm Warning | BOX | 27 min |
| Jul 17, 5:43 PM EDT | Flash Flood Warning | BOX | 2 hr |
| Jul 18, 4:01 AM EDT | Excessive Heat Watch | BOX | 12 hr |
| Jul 18, 3:47 PM EDT | Excessive Heat Warning | BOX | 3 days |
| Jul 22, 8:51 PM EDT | Mesoscale Discussion | SPC | 84 min |
| Jul 23, 3:27 AM EDT | Flash Flood Watch | BOX | 10 hr |
| Jul 28, 4:00 PM EDT | Heat Advisory | BOX | 3 days |
| Jul 29, 3:45 PM EDT | Special Weather Statement | BOX | 30 min |
| Jul 29, 4:30 PM EDT | Special Weather Statement | BOX | 30 min |
| Jul 31, 12:39 PM EDT | Mesoscale Discussion | SPC | 66 min |
| Jul 31, 1:17 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 31, 3:20 PM EDT | Special Weather Statement | BOX | 25 min |
| Jul 31, 3:35 PM EDT | Special Weather Statement | BOX | 55 min |
| Jul 31, 3:37 PM EDT | Special Weather Statement | BOX | 53 min |
| Jul 31, 3:41 PM EDT | Severe Thunderstorm Warning | BOX | 64 min |
| Jul 31, 4:14 PM EDT | Severe Thunderstorm Warning | BOX | 61 min |
| Jul 31, 4:19 PM EDT | Mesoscale Discussion | SPC | 56 min |
| Aug 4, 4:39 PM EDT | Severe Thunderstorm Warning | BOX | 66 min |
| Aug 6, 6:19 AM EDT | Dense Fog Advisory | BOX | 97 min |
| Aug 7, 12:39 PM EDT | Special Weather Statement | BOX | 51 min |
| Aug 7, 1:02 PM EDT | Mesoscale Discussion | SPC | 88 min |
| Aug 7, 1:11 PM EDT | Special Weather Statement | BOX | 49 min |
| Aug 7, 8:58 PM EDT | Severe Thunderstorm Warning | BOX | 62 min |
| Aug 7, 10:30 PM EDT | Severe Thunderstorm Warning | BOX | 60 min |
| Aug 7, 10:52 PM EDT | Areal Flood Warning | BOX | 113 min |
| Aug 8, 12:14 AM EDT | Areal Flood Warning | BOX | 2 hr |
| Aug 8, 1:19 AM EDT | Severe Thunderstorm Warning | BOX | 56 min |
| Aug 16, 4:10 AM EDT | Dense Fog Advisory | BOX | 4 hr |
| Aug 18, 3:27 PM EDT | Heat Advisory | BOX | 26 hr |
| Aug 18, 6:24 PM EDT | Severe Thunderstorm Warning | BOX | 40 min |
| Aug 19, 1:38 PM EDT | Mesoscale Discussion | SPC | 67 min |
| Aug 19, 2:20 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 19, 3:45 PM EDT | Severe Thunderstorm Warning | BOX | 60 min |
| Aug 19, 4:25 PM EDT | Severe Thunderstorm Warning | BOX | 65 min |
| Aug 21, 11:31 AM EDT | Mesoscale Discussion | SPC | 119 min |
| Aug 21, 1:53 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 21, 3:55 PM EDT | Mesoscale Discussion | SPC | 95 min |
| Aug 21, 6:20 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Aug 21, 7:14 PM EDT | Severe Thunderstorm Warning | BOX | 38 min |
| Aug 26, 11:26 AM EDT | Rip Current Statement | BOX | 7 hr |
| Aug 27, 2:55 AM EDT | Rip Current Statement | BOX | 15 hr |
| Aug 28, 2:53 AM EDT | Flash Flood Watch | BOX | 28 hr |
| Aug 28, 11:10 PM EDT | Areal Flood Warning | BOX | 3 hr |
| Sep 2, 3:58 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 2, 5:50 PM EDT | Special Weather Statement | BOX | 55 min |
| Sep 2, 6:23 PM EDT | Special Weather Statement | BOX | 37 min |
| Sep 4, 3:27 PM EDT | Mesoscale Discussion | SPC | 93 min |
| Sep 6, 4:54 AM EDT | High Surf Advisory | BOX | 47 hr |
| Sep 15, 6:09 AM EDT | Dense Fog Advisory | BOX | 3 hr |
| Sep 18, 3:51 AM EDT | Rip Current Statement | BOX | 20 hr |
| Sep 18, 3:34 PM EDT | High Surf Advisory | BOX | 53 hr |
| Sep 26, 6:45 AM EDT | Dense Fog Advisory | BOX | 2 hr |
| Sep 26, 3:40 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 27, 2:58 AM EDT | Dense Fog Advisory | BOX | 4 hr |
| Sep 29, 3:53 AM EDT | Rip Current Statement | BOX | 4 days |
| Oct 4, 3:29 AM EDT | Frost Advisory | BOX | 28 hr |
| Oct 8, 2:48 PM EDT | Coastal Flood Watch | BOX | 37 hr |
| Oct 9, 3:16 AM EDT | Wind Advisory | BOX | 69 hr |
| Oct 9, 3:36 AM EDT | Flood Watch | BOX | 42 hr |
| Oct 10, 3:30 AM EDT | Coastal Flood Advisory | BOX | 22 hr |
| Oct 15, 4:17 PM EDT | Frost Advisory | BOX | 12 hr |
| Oct 16, 4:23 AM EDT | Wind Advisory | BOX | 38 hr |
| Oct 16, 3:46 PM EDT | High Wind Warning | BOX | 14 hr |
| Oct 23, 6:35 AM EDT | Dense Fog Advisory | BOX | 2 hr |
| Oct 27, 4:22 PM EDT | Coastal Flood Advisory | BOX | 23 hr |
| Oct 28, 4:30 PM EDT | Coastal Flood Advisory | BOX | 10 hr |
| Oct 29, 8:02 AM EDT | Coastal Flood Statement | BOX | 7 hr |
| Oct 30, 3:42 AM EDT | High Wind Watch | BOX | 24 hr |
| Oct 30, 3:34 PM EDT | Wind Advisory | BOX | 47 hr |
| Oct 31, 4:08 AM EDT | High Wind Warning | BOX | 27 hr |
| Nov 17, 3:21 AM EST | Coastal Flood Advisory | BOX | 38 hr |
| Nov 17, 3:28 AM EST | Winter Weather Advisory | BOX | 51 hr |
| Nov 23, 3:48 PM EST | Wind Advisory | BOX | 30 hr |
| Nov 27, 6:55 PM EST | Special Weather Statement | BOX | 50 min |
| Nov 28, 3:04 AM EST | Wind Advisory | BOX | 21 hr |
| Nov 29, 3:58 PM EST | Winter Storm Watch | BOX | 36 hr |
| Nov 30, 3:49 AM EST | Winter Storm Warning | BOX | 3 days |
| Nov 30, 3:42 PM EST | Winter Weather Advisory | BOX | 69 hr |
| Dec 1, 7:05 PM EST | Mesoscale Discussion | SPC | 5 hr |
| Dec 1, 8:22 PM EST | Coastal Flood Advisory | BOX | 21 hr |
| Dec 3, 4:36 AM EST | Special Weather Statement | BOX | 114 min |
| Dec 3, 4:51 AM EST | Mesoscale Discussion | SPC | 2 hr |
| Dec 10, 3:35 AM EST | Winter Weather Advisory | BOX | 32 hr |
| Dec 13, 2:46 AM EST | Flood Watch | BOX | 31 hr |
| Dec 13, 2:49 AM EST | Wind Advisory | BOX | 34 hr |
| Dec 13, 4:40 PM EST | Coastal Flood Statement | BOX | 21 hr |
| Dec 14, 3:30 PM EST | Wind Advisory | BOX | 28 hr |
| Dec 16, 3:44 AM EST | Winter Weather Advisory | BOX | 41 hr |
| Dec 29, 4:01 AM EST | Winter Weather Advisory | BOX | 51 hr |
| Dec 30, 6:01 PM EST | Special Weather Statement | BOX | 29 min |
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 archive20182020
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.