Alert archive / Massachusetts / Norfolk County
Weather alerts in Norfolk County, Massachusetts, 2015
178 weather alerts in 2015, 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 2015. Tap one for its archive.
- Alerts
- 178
- Warnings
- 34
- Watches
- 23
- Advisories
- 66
- Busiest month
- January33 alerts
- Busiest day
- June 23, 20159 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
1 of 2 tornado warnings covering Norfolk County in 2015 had a tornado report inside them; 1 of 1 tornado reports fell inside a warning, on average 23 minutes after it went out.
Norfolk County, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 2 | 1 | 50% | 1 | 100% | 23 min |
| Severe thunderstorm warnings | 8 | 6 | 25% | 13 | 77% | 22 min |
| Flash flood warnings | 2 | 0 | 100% | 0 |
Each office's whole area, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Boston/Norton, MA: tornado warnings | 10 | 1 | 90% | 2 | 50% | 23 min |
| NWS Boston/Norton, MA: severe thunderstorm warnings | 91 | 52 | 43% | 309 | 75% | 23 min |
| NWS Boston/Norton, MA: flash flood warnings | 12 | 1 | 92% | 5 | 100% | 39 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, 4:09 PM EST | Winter Weather Advisory | BOX | 44 hr |
| Jan 4, 1:11 PM EST | Dense Fog Advisory | BOX | 9 hr |
| Jan 5, 4:24 AM EST | Wind Advisory | BOX | 14 hr |
| Jan 6, 4:31 PM EST | Wind Chill Advisory | BOX | 42 hr |
| Jan 8, 3:25 PM EST | Wind Advisory | BOX | 24 hr |
| Jan 14, 10:22 PM EST | Winter Weather Advisory | BOX | 22 hr |
| Jan 16, 1:57 PM EST | Special Weather Statement | BOX | 2 hr |
| Jan 18, 7:41 AM EST | Freezing Rain Advisory | BOX | 7 hr |
| Jan 18, 8:21 PM EST | Special Weather Statement | BOX | 84 min |
| Jan 18, 8:23 PM EST | Special Weather Statement | BOX | 82 min |
| Jan 18, 8:24 PM EST | Special Weather Statement | BOX | 81 min |
| Jan 22, 2:33 PM EST | Winter Storm Watch | BOX | 25 hr |
| Jan 23, 4:06 AM EST | Winter Weather Advisory | BOX | 39 hr |
| Jan 23, 11:48 AM EST | Coastal Flood Advisory | BOX | 28 hr |
| Jan 23, 3:55 PM EST | Winter Storm Warning | BOX | 27 hr |
| Jan 24, 4:28 AM EST | Special Weather Statement | BOX | 62 min |
| Jan 24, 5:47 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Jan 25, 3:52 AM EST | Blizzard Watch | BOX | 12 hr |
| Jan 25, 4:07 AM EST | Coastal Flood Watch | BOX | 31 hr |
| Jan 25, 3:58 PM EST | Blizzard Warning | BOX | 54 hr |
| Jan 25, 3:58 PM EST | Winter Storm Warning | BOX | 54 hr |
| Jan 25, 4:19 PM EST | Coastal Flood Warning | BOX | 39 hr |
| Jan 26, 10:44 AM EST | Coastal Flood Warning | BOX | 33 hr |
| Jan 26, 11:32 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Jan 27, 4:28 AM EST | Mesoscale Discussion | SPC | 5 hr |
| Jan 27, 10:24 AM EST | Mesoscale Discussion | SPC | 5 hr |
| Jan 27, 8:27 PM EST | Coastal Flood Advisory | BOX | 11 hr |
| Jan 27, 10:16 PM EST | Winter Weather Advisory | BOX | 3 hr |
| Jan 27, 11:29 PM EST | Special Weather Statement | BOX | 3 hr |
| Jan 29, 3:42 AM EST | Winter Weather Advisory | BOX | 49 hr |
| Jan 30, 4:25 PM EST | Winter Storm Watch | BOX | 37 hr |
| Jan 30, 4:30 PM EST | Wind Advisory | BOX | 29 hr |
| Jan 31, 3:23 PM EST | Winter Storm Warning | BOX | 56 hr |
| Feb 1, 1:34 PM EST | Coastal Flood Advisory | BOX | 22 hr |
| Feb 2, 5:09 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Feb 2, 1:56 PM EST | Special Weather Statement | BOX | 49 min |
| Feb 2, 3:14 PM EST | Special Weather Statement | BOX | 91 min |
| Feb 5, 3:49 AM EST | Wind Chill Advisory | BOX | 29 hr |
| Feb 6, 3:22 PM EST | Winter Storm Watch | BOX | 24 hr |
| Feb 7, 2:55 PM EST | Winter Storm Warning | BOX | 61 hr |
| Feb 9, 11:05 AM EST | Special Weather Statement | BOX | 85 min |
| Feb 12, 4:14 PM EST | Blizzard Watch | BOX | 23 hr |
| Feb 12, 4:14 PM EST | Winter Storm Watch | BOX | 36 hr |
| Feb 13, 4:13 AM EST | Coastal Flood Watch | BOX | 12 hr |
| Feb 13, 3:18 PM EST | Blizzard Warning | BOX | 49 hr |
| Feb 13, 4:07 PM EST | Coastal Flood Warning | BOX | 43 hr |
| Feb 13, 4:07 PM EST | Coastal Flood Advisory | BOX | 43 hr |
| Feb 14, 4:40 AM EST | Wind Chill Warning | BOX | 53 hr |
| Feb 15, 4:17 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Feb 15, 2:42 PM EST | Winter Weather Advisory | BOX | 9 hr |
| Feb 18, 10:55 PM EST | Special Weather Statement | BOX | 110 min |
| Feb 19, 4:51 AM EST | Wind Chill Advisory | BOX | 29 hr |
| Feb 20, 4:27 PM EST | Winter Weather Advisory | BOX | 43 hr |
| Feb 22, 4:25 PM EST | Wind Chill Advisory | BOX | 38 hr |
| Feb 23, 3:54 PM EST | Winter Weather Advisory | BOX | 39 hr |
| Feb 28, 4:06 AM EST | Winter Storm Watch | BOX | 24 hr |
| Feb 28, 3:08 PM EST | Winter Weather Advisory | BOX | 35 hr |
| Mar 1, 4:15 AM EST | Winter Storm Warning | BOX | 22 hr |
| Mar 2, 3:38 PM EST | Winter Weather Advisory | BOX | 36 hr |
| Mar 3, 7:01 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Mar 5, 12:58 PM EST | Winter Weather Advisory | BOX | 3 hr |
| Mar 11, 1:51 AM EDT | Dense Fog Advisory | BOX | 6 hr |
| Mar 13, 4:12 PM EDT | Freezing Rain Advisory | BOX | 12 hr |
| Mar 14, 4:02 AM EDT | Freezing Rain Advisory | BOX | 6 hr |
| Mar 16, 3:28 PM EDT | Wind Advisory | BOX | 52 hr |
| Mar 17, 4:10 PM EDT | Special Weather Statement | BOX | 110 min |
| Mar 26, 6:11 AM EDT | Dense Fog Advisory | BOX | 18 hr |
| Apr 3, 3:55 AM EDT | Wind Advisory | BOX | 38 hr |
| Apr 3, 10:25 PM EDT | Dense Fog Advisory | BOX | 8 hr |
| Apr 4, 4:53 AM EDT | Special Weather Statement | BOX | 37 min |
| Apr 4, 5:29 AM EDT | Special Weather Statement | BOX | 61 min |
| Apr 15, 4:24 AM EDT | Red Flag Warning | BOX | 15 hr |
| Apr 19, 3:18 PM EDT | Coastal Flood Advisory | BOX | 37 hr |
| Apr 21, 3:33 AM EDT | Special Weather Statement | BOX | 57 min |
| Apr 22, 5:24 PM EDT | Special Weather Statement | BOX | 81 min |
| Apr 22, 6:26 PM EDT | Special Weather Statement | BOX | 49 min |
| May 3, 4:09 PM EDT | Fire Weather Watch | BOX | 12 hr |
| May 8, 3:08 PM EDT | Dense Fog Advisory | BOX | 16 hr |
| May 9, 2:56 PM EDT | Dense Fog Advisory | BOX | 19 hr |
| May 11, 4:20 PM EDT | Dense Fog Advisory | BOX | 18 hr |
| May 11, 10:10 PM EDT | Dense Fog Advisory | BOX | 9 hr |
| May 12, 2:38 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| May 12, 4:03 PM EDT | Fire Weather Watch | BOX | 11 hr |
| May 12, 7:08 PM EDT | Severe Thunderstorm Warning | BOX | 37 min |
| May 13, 3:14 AM EDT | Frost Advisory | BOX | 28 hr |
| May 13, 3:20 AM EDT | Red Flag Warning | BOX | 15 hr |
| May 28, 11:54 AM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 28, 6:30 PM EDT | Special Weather Statement | BOX | 30 min |
| May 30, 12:00 AM EDT | Dense Fog Advisory | BOX | 8 hr |
| May 31, 3:14 PM EDT | Flash Flood Warning | BOX | 3 hr |
| May 31, 3:22 PM EDT | Areal Flood Advisory | BOX | 53 min |
| May 31, 3:29 PM EDT | Flash Flood Watch | BOX | 41 hr |
| May 31, 4:01 PM EDT | Areal Flood Advisory | BOX | 119 min |
| May 31, 4:51 PM EDT | Flash Flood Warning | BOX | 3 hr |
| Jun 20, 4:19 PM EDT | Flood Watch | BOX | 20 hr |
| Jun 22, 4:06 AM EDT | Dense Fog Advisory | BOX | 4 hr |
| Jun 23, 10:12 AM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 23, 2:46 PM EDT | Mesoscale Discussion | SPC | 89 min |
| Jun 23, 3:47 PM EDT | Tornado Watch | SPC | 7 hr |
| Jun 23, 4:53 PM EDT | Mesoscale Discussion | SPC | 97 min |
| Jun 23, 5:08 PM EDT | Severe Thunderstorm Warning | BOX | 52 min |
| Jun 23, 5:16 PM EDT | Tornado Warning | BOX | 44 min |
| Jun 23, 5:46 PM EDT | Tornado Warning | BOX | 30 min |
| Jun 23, 5:52 PM EDT | Areal Flood Warning | BOX | 113 min |
| Jun 23, 6:55 PM EDT | Mesoscale Discussion | SPC | 95 min |
| Jun 27, 4:22 AM EDT | Wind Advisory | BOX | 31 hr |
| Jun 27, 4:28 AM EDT | Flood Watch | BOX | 31 hr |
| Jun 27, 3:51 PM EDT | High Surf Advisory | BOX | 28 hr |
| Jul 1, 7:28 AM EDT | Severe Thunderstorm Warning | BOX | 62 min |
| Jul 1, 1:17 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 7, 7:48 PM EDT | Flash Flood Watch | BOX | 24 hr |
| Jul 15, 11:41 AM EDT | Flash Flood Watch | BOX | 9 hr |
| Jul 24, 2:59 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 28, 2:22 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Jul 28, 2:25 PM EDT | Special Weather Statement | BOX | 50 min |
| Jul 28, 3:05 PM EDT | Severe Thunderstorm Warning | BOX | 55 min |
| Aug 1, 2:24 PM EDT | Special Weather Statement | BOX | 51 min |
| Aug 4, 6:09 AM EDT | Severe Thunderstorm Warning | BOX | 66 min |
| Aug 4, 6:53 AM EDT | Severe Thunderstorm Warning | BOX | 52 min |
| Aug 4, 12:18 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 4, 2:21 PM EDT | Mesoscale Discussion | SPC | 84 min |
| Aug 4, 3:50 PM EDT | Severe Thunderstorm Warning | BOX | 55 min |
| Aug 4, 4:07 PM EDT | Areal Flood Warning | BOX | 113 min |
| Aug 4, 4:14 PM EDT | Mesoscale Discussion | SPC | 91 min |
| Aug 4, 6:17 PM EDT | Special Weather Statement | BOX | 43 min |
| Aug 4, 6:49 PM EDT | Mesoscale Discussion | SPC | 86 min |
| Aug 11, 11:39 AM EDT | Special Weather Statement | BOX | 96 min |
| Aug 15, 6:26 PM EDT | Special Weather Statement | BOX | 49 min |
| Aug 15, 6:55 PM EDT | Special Weather Statement | BOX | 50 min |
| Aug 15, 7:02 PM EDT | Severe Thunderstorm Warning | BOX | 33 min |
| Aug 15, 7:06 PM EDT | Areal Flood Warning | BOX | 6 hr |
| Aug 15, 7:21 PM EDT | Special Weather Statement | BOX | 39 min |
| Aug 15, 7:58 PM EDT | Special Weather Statement | BOX | 47 min |
| Aug 15, 8:35 PM EDT | Special Weather Statement | BOX | 40 min |
| Aug 15, 8:58 PM EDT | Areal Flood Warning | BOX | 3 hr |
| Aug 15, 9:37 PM EDT | Special Weather Statement | BOX | 38 min |
| Aug 15, 10:30 PM EDT | Special Weather Statement | BOX | 45 min |
| Aug 18, 3:02 PM EDT | Special Weather Statement | BOX | 43 min |
| Aug 18, 3:46 PM EDT | Special Weather Statement | BOX | 44 min |
| Aug 18, 3:55 PM EDT | Special Weather Statement | BOX | 50 min |
| Aug 18, 4:10 PM EDT | Areal Flood Warning | BOX | 2 hr |
| Aug 18, 4:45 PM EDT | Special Weather Statement | BOX | 45 min |
| Aug 18, 5:27 PM EDT | Areal Flood Warning | BOX | 3 hr |
| Aug 20, 4:13 AM EDT | Dense Fog Advisory | BOX | 5 hr |
| Sep 10, 11:35 AM EDT | Flash Flood Watch | BOX | 17 hr |
| Sep 19, 3:42 AM EDT | Dense Fog Advisory | BOX | 4 hr |
| Sep 30, 7:57 AM EDT | Special Weather Statement | BOX | 93 min |
| Sep 30, 9:27 AM EDT | Special Weather Statement | BOX | 78 min |
| Sep 30, 10:32 AM EDT | Areal Flood Warning | BOX | 118 min |
| Sep 30, 12:29 PM EDT | Coastal Flood Advisory | BOX | 3 hr |
| Sep 30, 4:01 PM EDT | Coastal Flood Advisory | BOX | 24 hr |
| Oct 1, 4:34 PM EDT | Coastal Flood Advisory | BOX | 24 hr |
| Oct 2, 2:55 PM EDT | Coastal Flood Advisory | BOX | 27 hr |
| Oct 10, 3:27 AM EDT | Frost Advisory | BOX | 28 hr |
| Oct 16, 3:13 PM EDT | Freeze Watch | BOX | 12 hr |
| Oct 17, 3:10 AM EDT | Freeze Watch | BOX | 25 hr |
| Oct 17, 3:10 AM EDT | Freeze Warning | BOX | 30 hr |
| Oct 18, 4:08 AM EDT | Freeze Warning | BOX | 29 hr |
| Oct 27, 4:01 PM EDT | Wind Advisory | BOX | 41 hr |
| Oct 27, 4:32 PM EDT | Coastal Flood Advisory | BOX | 21 hr |
| Oct 27, 4:32 PM EDT | Coastal Flood Advisory | BOX | 34 hr |
| Oct 29, 3:43 AM EDT | Coastal Flood Advisory | BOX | 11 hr |
| Oct 29, 5:18 AM EDT | Special Weather Statement | BOX | 42 min |
| Nov 9, 3:47 PM EST | Wind Advisory | BOX | 51 hr |
| Nov 11, 4:20 AM EST | Coastal Flood Statement | BOX | 9 hr |
| Nov 20, 2:55 AM EST | Special Weather Statement | BOX | 35 min |
| Nov 20, 3:44 AM EST | Special Weather Statement | BOX | 91 min |
| Dec 2, 3:03 PM EST | Dense Fog Advisory | BOX | 4 hr |
| Dec 10, 10:19 PM EST | Dense Fog Advisory | BOX | 11 hr |
| Dec 11, 9:01 AM EST | Dense Fog Advisory | BOX | 2 hr |
| Dec 14, 11:21 AM EST | Dense Fog Advisory | BOX | 13 hr |
| Dec 14, 3:03 PM EST | Wind Advisory | BOX | 26 hr |
| Dec 21, 3:20 AM EST | Wind Advisory | BOX | 13 hr |
| Dec 23, 2:44 AM EST | Dense Fog Advisory | BOX | 7 hr |
| Dec 24, 5:39 PM EST | Dense Fog Advisory | BOX | 15 hr |
| Dec 27, 3:10 PM EST | Winter Weather Advisory | BOX | 46 hr |
| Dec 29, 1:06 PM EST | Freezing Rain Advisory | BOX | 9 hr |
| Dec 30, 3:49 AM EST | Freezing Rain Advisory | BOX | 23 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 archive20142016
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.