Alert archive / Massachusetts / Bristol County
Weather alerts in Bristol County, Massachusetts, 2009
138 weather alerts in 2009, 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 2009. Tap one for its archive.
- Alerts
- 138
- Warnings
- 28
- Watches
- 20
- Advisories
- 75
- Busiest month
- July33 alerts
- Busiest day
- July 31, 20097 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, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 12 | 7 | 42% | 4 | 100% | 20 min |
| Flash flood warnings | 2 | 0 | 100% | 0 |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Boston/Norton, MA: tornado warnings | 2 | 0 | 100% | 2 | 0% | |
| NWS Boston/Norton, MA: severe thunderstorm warnings | 114 | 66 | 42% | 250 | 78% | 21 min |
| NWS Boston/Norton, MA: flash flood warnings | 22 | 3 | 86% | 13 | 62% | 68 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 6, 4:53 AM EST | Winter Weather Advisory | BOX | 32 hr |
| Jan 7, 6:08 AM EST | Mesoscale Discussion | SPC | 3 hr |
| Jan 7, 9:16 AM EST | Areal Flood Advisory | BOX | 8 hr |
| Jan 7, 4:32 PM EST | Wind Advisory | BOX | 26 hr |
| Jan 9, 4:25 AM EST | Winter Storm Watch | BOX | 24 hr |
| Jan 10, 4:39 AM EST | Winter Storm Warning | BOX | 30 hr |
| Jan 10, 4:39 AM EST | Winter Weather Advisory | BOX | 29 hr |
| Jan 10, 7:58 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Jan 14, 4:02 PM EST | Winter Weather Advisory | BOX | 29 hr |
| Jan 17, 4:22 PM EST | Winter Storm Warning | BOX | 22 hr |
| Jan 17, 4:22 PM EST | Winter Weather Advisory | BOX | 22 hr |
| Jan 18, 4:16 PM EST | Winter Weather Advisory | BOX | 14 hr |
| Jan 26, 3:35 PM EST | Winter Storm Watch | BOX | 24 hr |
| Jan 27, 3:51 PM EST | Winter Weather Advisory | BOX | 23 hr |
| Jan 28, 3:33 AM EST | Wind Advisory | BOX | 23 hr |
| Feb 2, 4:07 PM EST | Winter Storm Watch | BOX | 13 hr |
| Feb 3, 4:40 AM EST | Winter Weather Advisory | BOX | 22 hr |
| Feb 11, 4:40 AM EST | High Wind Watch | BOX | 11 hr |
| Feb 11, 3:48 PM EST | Wind Advisory | BOX | 36 hr |
| Feb 19, 4:55 AM EST | Dense Fog Advisory | BOX | 3 hr |
| Feb 27, 3:34 AM EST | Wind Advisory | BOX | 16 hr |
| Feb 28, 5:07 AM EST | Winter Storm Watch | BOX | 36 hr |
| Mar 1, 4:27 AM EST | Winter Storm Warning | BOX | 35 hr |
| Mar 1, 4:27 AM EST | Winter Weather Advisory | BOX | 12 hr |
| Mar 1, 4:43 PM EST | Winter Weather Advisory | BOX | 26 hr |
| Mar 1, 9:09 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Mar 2, 12:41 AM EST | Mesoscale Discussion | SPC | 4 hr |
| Apr 2, 8:40 PM EDT | Dense Fog Advisory | BOX | 12 hr |
| Apr 3, 5:39 PM EDT | Dense Fog Advisory | BOX | 6 hr |
| Apr 6, 4:35 AM EDT | Wind Advisory | BOX | 17 hr |
| Apr 6, 2:28 PM EDT | Areal Flood Advisory | BOX | 3 hr |
| Apr 15, 4:37 PM EDT | Fire Weather Watch | BOX | 10 hr |
| Apr 16, 4:50 PM EDT | Fire Weather Watch | BOX | 11 hr |
| Apr 17, 4:11 AM EDT | Red Flag Warning | BOX | 16 hr |
| Apr 20, 4:19 AM EDT | Wind Advisory | BOX | 24 hr |
| Apr 27, 4:40 PM EDT | Fire Weather Watch | BOX | 12 hr |
| Apr 28, 4:26 AM EDT | Red Flag Warning | BOX | 17 hr |
| Apr 29, 4:17 AM EDT | Frost Advisory | BOX | 27 hr |
| May 15, 9:54 PM EDT | Dense Fog Advisory | BOX | 10 hr |
| May 18, 4:18 AM EDT | Frost Advisory | BOX | 27 hr |
| May 20, 4:12 PM EDT | Fire Weather Watch | BOX | 12 hr |
| May 21, 3:47 AM EDT | Red Flag Warning | BOX | 16 hr |
| Jun 19, 4:35 PM EDT | Flood Watch | BOX | 36 hr |
| Jun 27, 4:13 PM EDT | Areal Flood Advisory | BOX | 3 hr |
| Jun 27, 4:16 PM EDT | Severe Thunderstorm Warning | BOX | 44 min |
| Jun 27, 4:24 PM EDT | Flash Flood Warning | BOX | 2 hr |
| Jun 27, 4:38 PM EDT | Mesoscale Discussion | SPC | 67 min |
| Jun 27, 6:45 PM EDT | Areal Flood Advisory | BOX | 3 hr |
| Jul 1, 4:54 AM EDT | Flash Flood Watch | BOX | 42 hr |
| Jul 1, 10:57 AM EDT | Areal Flood Advisory | BOX | 3 hr |
| Jul 1, 1:20 PM EDT | Severe Thunderstorm Warning | BOX | 25 min |
| Jul 1, 2:09 PM EDT | Areal Flood Warning | BOX | 3 hr |
| Jul 2, 6:57 AM EDT | Areal Flood Advisory | BOX | 3 hr |
| Jul 2, 7:50 AM EDT | Areal Flood Advisory | BOX | 3 hr |
| Jul 2, 8:18 AM EDT | Flash Flood Warning | BOX | 4 hr |
| Jul 2, 12:18 PM EDT | Areal Flood Advisory | BOX | 3 hr |
| Jul 2, 3:20 PM EDT | Mesoscale Discussion | SPC | 55 min |
| Jul 3, 4:08 AM EDT | Flash Flood Watch | BOX | 16 hr |
| Jul 7, 7:00 PM EDT | Areal Flood Advisory | BOX | 4 hr |
| Jul 8, 3:33 PM EDT | Areal Flood Advisory | BOX | 115 min |
| Jul 8, 3:52 PM EDT | Severe Thunderstorm Warning | BOX | 38 min |
| Jul 8, 4:27 PM EDT | Severe Thunderstorm Warning | BOX | 36 min |
| Jul 8, 4:45 PM EDT | Severe Thunderstorm Warning | BOX | 45 min |
| Jul 8, 4:49 PM EDT | Severe Thunderstorm Warning | BOX | 41 min |
| Jul 8, 5:26 PM EDT | Areal Flood Advisory | BOX | 62 min |
| Jul 21, 9:28 AM EDT | Areal Flood Advisory | BOX | 6 hr |
| Jul 23, 2:54 PM EDT | Flood Watch | BOX | 19 hr |
| Jul 23, 4:16 PM EDT | Coastal Flood Advisory | BOX | 11 hr |
| Jul 23, 4:16 PM EDT | High Surf Advisory | BOX | 28 hr |
| Jul 23, 10:29 PM EDT | Areal Flood Advisory | BOX | 4 hr |
| Jul 24, 2:12 AM EDT | Areal Flood Advisory | BOX | 4 hr |
| Jul 26, 1:13 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 26, 3:14 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 26, 3:51 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 31, 1:29 PM EDT | Areal Flood Advisory | BOX | 114 min |
| Jul 31, 2:32 PM EDT | Mesoscale Discussion | SPC | 88 min |
| Jul 31, 4:50 PM EDT | Severe Thunderstorm Warning | BOX | 55 min |
| Jul 31, 4:58 PM EDT | Areal Flood Advisory | BOX | 2 hr |
| Jul 31, 5:22 PM EDT | Severe Thunderstorm Warning | BOX | 23 min |
| Jul 31, 5:32 PM EDT | Severe Thunderstorm Warning | BOX | 58 min |
| Jul 31, 5:40 PM EDT | Areal Flood Advisory | BOX | 80 min |
| Aug 5, 2:16 PM EDT | Mesoscale Discussion | SPC | 59 min |
| Aug 5, 4:08 PM EDT | Severe Thunderstorm Warning | BOX | 42 min |
| Aug 5, 7:08 PM EDT | Severe Thunderstorm Warning | BOX | 52 min |
| Aug 5, 7:17 PM EDT | Areal Flood Advisory | BOX | 58 min |
| Aug 5, 8:01 PM EDT | Areal Flood Advisory | BOX | 32 min |
| Aug 10, 4:13 AM EDT | Heat Advisory | BOX | 11 hr |
| Aug 20, 3:21 PM EDT | Severe Thunderstorm Warning | BOX | 24 min |
| Aug 21, 4:23 PM EDT | High Surf Advisory | BOX | 72 hr |
| Aug 21, 5:55 PM EDT | Mesoscale Discussion | SPC | 80 min |
| Aug 23, 2:43 AM EDT | Areal Flood Advisory | BOX | 3 hr |
| Aug 28, 11:07 AM EDT | Coastal Flood Statement | BOX | 6 hr |
| Aug 28, 4:29 PM EDT | Flood Watch | BOX | 26 hr |
| Aug 28, 5:18 PM EDT | High Surf Advisory | BOX | 53 hr |
| Aug 29, 1:20 PM EDT | Areal Flood Advisory | BOX | 3 hr |
| Aug 29, 4:18 PM EDT | Areal Flood Advisory | BOX | 3 hr |
| Sep 12, 11:10 PM EDT | Areal Flood Advisory | BOX | 65 min |
| Sep 13, 12:23 AM EDT | Areal Flood Advisory | BOX | 52 min |
| Sep 19, 2:49 AM EDT | Frost Advisory | BOX | 29 hr |
| Sep 28, 4:01 AM EDT | High Surf Advisory | BOX | 16 hr |
| Oct 3, 4:51 AM EDT | Areal Flood Advisory | BOX | 5 hr |
| Oct 3, 9:55 AM EDT | Areal Flood Advisory | BOX | 3 hr |
| Oct 3, 11:18 AM EDT | Areal Flood Advisory | BOX | 3 hr |
| Oct 3, 12:58 PM EDT | Areal Flood Advisory | BOX | 2 hr |
| Oct 6, 3:28 PM EDT | Wind Advisory | BOX | 36 hr |
| Oct 7, 9:47 AM EDT | Coastal Flood Advisory | BOX | 2 hr |
| Oct 11, 3:05 AM EDT | Frost Advisory | BOX | 29 hr |
| Oct 14, 4:09 AM EDT | Frost Advisory | BOX | 28 hr |
| Oct 14, 4:09 AM EDT | Freeze Warning | BOX | 28 hr |
| Oct 14, 4:43 PM EDT | Coastal Flood Statement | BOX | 36 hr |
| Oct 15, 4:43 AM EDT | Wind Advisory | BOX | 29 hr |
| Oct 17, 4:15 PM EDT | Wind Advisory | BOX | 36 hr |
| Oct 19, 11:42 PM EDT | Freeze Warning | BOX | 7 hr |
| Oct 24, 9:19 PM EDT | Wind Advisory | BOX | 5 hr |
| Oct 31, 3:31 AM EDT | Wind Advisory | BOX | 16 hr |
| Nov 15, 7:09 PM EST | Dense Fog Advisory | BOX | 6 hr |
| Nov 27, 4:10 AM EST | Wind Advisory | BOX | 34 hr |
| Nov 28, 8:40 AM EST | High Wind Warning | BOX | 6 hr |
| Dec 2, 4:06 AM EST | Coastal Flood Watch | BOX | 12 hr |
| Dec 2, 4:16 AM EST | High Wind Watch | BOX | 12 hr |
| Dec 2, 4:16 PM EST | Coastal Flood Warning | BOX | 18 hr |
| Dec 2, 4:16 PM EST | Coastal Flood Advisory | BOX | 20 hr |
| Dec 2, 4:25 PM EST | High Wind Warning | BOX | 18 hr |
| Dec 2, 4:25 PM EST | Wind Advisory | BOX | 18 hr |
| Dec 3, 5:38 AM EST | Areal Flood Advisory | BOX | 112 min |
| Dec 5, 4:36 AM EST | Winter Weather Advisory | BOX | 22 hr |
| Dec 8, 3:39 PM EST | Coastal Flood Advisory | BOX | 27 hr |
| Dec 8, 3:59 PM EST | Winter Weather Advisory | BOX | 19 hr |
| Dec 8, 4:11 PM EST | Wind Advisory | BOX | 23 hr |
| Dec 18, 4:17 AM EST | Winter Storm Watch | BOX | 11 hr |
| Dec 18, 3:20 PM EST | Blizzard Watch | BOX | 13 hr |
| Dec 18, 3:20 PM EST | Winter Storm Watch | BOX | 13 hr |
| Dec 19, 4:23 AM EST | Blizzard Warning | BOX | 33 hr |
| Dec 19, 4:23 AM EST | Winter Storm Warning | BOX | 32 hr |
| Dec 19, 7:25 PM EST | Mesoscale Discussion | SPC | 5 hr |
| Dec 20, 12:32 AM EST | Mesoscale Discussion | SPC | 4 hr |
| Dec 29, 4:04 AM EST | Wind Advisory | BOX | 21 hr |
| Dec 31, 4:03 AM EST | Winter Weather Advisory | BOX | 11 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 | 12 |
| Severe Thunderstorm Watch | 1 |
| Mesoscale Discussion | 13 |
| Flooding | |
| Areal Flood Warning | 1 |
| Flash Flood Warning | 2 |
| Flash Flood Watch | 2 |
| Flood Watch | 3 |
| Areal Flood Advisory | 29 |
| Winter | |
| Blizzard Warning | 1 |
| Winter Storm Warning | 4 |
| Blizzard Watch | 1 |
| Winter Storm Watch | 6 |
| Winter Weather Advisory | 12 |
| Heat | |
| Heat Advisory | 1 |
| Cold | |
| Freeze Warning | 2 |
| Frost Advisory | 5 |
| Wind and dust | |
| High Wind Warning | 2 |
| High Wind Watch | 2 |
| Wind Advisory | 15 |
| Fire | |
| Red Flag Warning | 3 |
| Fire Weather Watch | 4 |
| Fog and smoke | |
| Dense Fog Advisory | 5 |
| Coast and beach | |
| Coastal Flood Warning | 1 |
| Coastal Flood Watch | 1 |
| Coastal Flood Advisory | 4 |
| High Surf Advisory | 4 |
| Coastal Flood Statement | 2 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20082010
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.