Alert archive / New Hampshire / Grafton County
Weather alerts in Grafton County, New Hampshire, 2021
130 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Grafton County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 130
- Warnings
- 31
- Watches
- 14
- Advisories
- 33
- Busiest month
- June31 alerts
- Busiest day
- September 15, 20218 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Grafton County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 23 | 21 | 9% | 27 | 89% | 17 min |
| Flash flood warnings | 2 | 2 | 0% | 0 |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Gray, ME: tornado warnings | 4 | 0 | 100% | 0 | ||
| NWS Gray, ME: severe thunderstorm warnings | 99 | 71 | 28% | 208 | 88% | 19 min |
| NWS Gray, ME: flash flood warnings | 20 | 10 | 50% | 37 | 95% | 124 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 15, 6:49 AM EST | Winter Weather Advisory | GYX | 36 hr |
| Jan 16, 4:33 AM EST | Mesoscale Discussion | SPC | 4 hr |
| Jan 17, 3:08 AM EST | Winter Weather Advisory | GYX | 13 hr |
| Jan 20, 11:10 AM EST | Special Weather Statement | GYX | 50 min |
| Jan 22, 2:36 PM EST | Special Weather Statement | GYX | 69 min |
| Jan 28, 3:23 AM EST | Wind Chill Advisory | GYX | 30 hr |
| Jan 30, 3:25 PM EST | Winter Storm Watch | GYX | 37 hr |
| Jan 31, 3:25 PM EST | Winter Storm Warning | GYX | 59 hr |
| Feb 2, 8:41 AM EST | Winter Weather Advisory | GYX | 10 hr |
| Feb 5, 11:45 AM EST | Special Weather Statement | GYX | 60 min |
| Feb 11, 3:57 AM EST | Wind Chill Advisory | GYX | 28 hr |
| Feb 14, 2:30 AM EST | Winter Storm Watch | GYX | 27 hr |
| Feb 15, 3:59 AM EST | Winter Storm Warning | GYX | 33 hr |
| Feb 16, 2:51 AM EST | Mesoscale Discussion | SPC | 4 hr |
| Feb 22, 10:40 AM EST | Winter Weather Advisory | GYX | 12 hr |
| Feb 26, 3:19 PM EST | Winter Weather Advisory | GYX | 28 hr |
| Mar 1, 2:39 AM EST | Wind Chill Advisory | GYX | 32 hr |
| Mar 1, 3:23 AM EST | Wind Advisory | GYX | 37 hr |
| Mar 1, 6:38 PM EST | Special Weather Statement | GYX | 37 min |
| Mar 12, 11:33 PM EST | Special Weather Statement | GYX | 42 min |
| Mar 13, 12:18 AM EST | Special Weather Statement | GYX | 42 min |
| Mar 14, 3:24 AM EDT | Wind Chill Advisory | GYX | 33 hr |
| Mar 26, 3:24 PM EDT | Special Weather Statement | GYX | 36 min |
| Mar 28, 3:28 AM EDT | Wind Advisory | GYX | 38 hr |
| Mar 28, 3:39 AM EDT | Flood Watch | GYX | 23 hr |
| Apr 14, 3:18 PM EDT | Winter Storm Watch | GYX | 12 hr |
| Apr 15, 3:14 AM EDT | Winter Storm Warning | GYX | 38 hr |
| Apr 30, 11:43 PM EDT | River Flood Warning | GYX | 4 hr |
| May 12, 3:30 AM EDT | Frost Advisory | GYX | 28 hr |
| May 16, 1:20 PM EDT | Special Weather Statement | GYX | 25 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, 4:46 PM EDT | Special Weather Statement | GYX | 29 min |
| May 26, 4:51 PM EDT | Severe Thunderstorm Warning | GYX | 54 min |
| May 26, 5:07 PM EDT | Severe Thunderstorm Warning | GYX | 53 min |
| May 26, 5:52 PM EDT | Severe Thunderstorm Warning | GYX | 53 min |
| May 27, 3:07 AM EDT | Frost Advisory | GYX | 28 hr |
| Jun 5, 2:33 PM EDT | Mesoscale Discussion | SPC | 117 min |
| Jun 6, 3:11 AM EDT | Heat Advisory | GYX | 63 hr |
| Jun 15, 2:38 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 15, 2:43 PM EDT | Special Weather Statement | GYX | 47 min |
| Jun 15, 3:24 PM EDT | Severe Thunderstorm Warning | GYX | 51 min |
| Jun 15, 6:40 PM EDT | Special Weather Statement | GYX | 35 min |
| Jun 19, 12:38 PM EDT | Mesoscale Discussion | SPC | 97 min |
| Jun 21, 1:11 PM EDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jun 21, 6:48 PM EDT | Special Weather Statement | GYX | 27 min |
| Jun 21, 6:56 PM EDT | Severe Thunderstorm Warning | GYX | 35 min |
| Jun 21, 7:01 PM EDT | Special Weather Statement | GYX | 29 min |
| Jun 21, 10:45 PM EDT | Special Weather Statement | GYX | 30 min |
| Jun 21, 11:19 PM EDT | Special Weather Statement | GYX | 26 min |
| Jun 21, 11:22 PM EDT | Special Weather Statement | GYX | 23 min |
| Jun 27, 3:37 PM EDT | Heat Advisory | GYX | 28 hr |
| Jun 28, 4:13 PM EDT | Heat Advisory | GYX | 28 hr |
| Jun 28, 4:40 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 28, 6:10 PM EDT | Special Weather Statement | GYX | 35 min |
| Jun 28, 6:15 PM EDT | Severe Thunderstorm Warning | GYX | 21 min |
| Jun 28, 6:42 PM EDT | Special Weather Statement | GYX | 33 min |
| Jun 28, 6:59 PM EDT | Special Weather Statement | GYX | 31 min |
| Jun 28, 7:38 PM EDT | Special Weather Statement | GYX | 37 min |
| Jun 29, 5:41 PM EDT | Special Weather Statement | GYX | 34 min |
| Jun 29, 6:12 PM EDT | Severe Thunderstorm Warning | GYX | 33 min |
| Jun 30, 11:04 AM EDT | Mesoscale Discussion | SPC | 116 min |
| Jun 30, 12:06 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 30, 1:52 PM EDT | Mesoscale Discussion | SPC | 83 min |
| Jun 30, 2:39 PM EDT | Special Weather Statement | GYX | 36 min |
| Jun 30, 3:02 PM EDT | Severe Thunderstorm Warning | GYX | 43 min |
| Jun 30, 3:10 PM EDT | Severe Thunderstorm Warning | GYX | 17 min |
| Jun 30, 4:01 PM EDT | Severe Thunderstorm Warning | GYX | 27 min |
| Jul 8, 4:09 AM EDT | Flash Flood Watch | GYX | 39 hr |
| Jul 14, 2:59 PM EDT | Special Weather Statement | GYX | 31 min |
| Jul 14, 3:11 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 14, 3:29 PM EDT | Special Weather Statement | GYX | 31 min |
| Jul 14, 3:32 PM EDT | Severe Thunderstorm Warning | GYX | 28 min |
| Jul 14, 3:58 PM EDT | Special Weather Statement | GYX | 32 min |
| Jul 14, 4:41 PM EDT | Severe Thunderstorm Warning | GYX | 34 min |
| Jul 20, 7:12 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 20, 8:55 PM EDT | Special Weather Statement | GYX | 50 min |
| Jul 20, 8:58 PM EDT | Severe Thunderstorm Warning | GYX | 47 min |
| Jul 20, 9:24 PM EDT | Severe Thunderstorm Warning | GYX | 29 min |
| Jul 20, 9:35 PM EDT | Severe Thunderstorm Warning | GYX | 40 min |
| Jul 20, 10:10 PM EDT | Severe Thunderstorm Warning | GYX | 50 min |
| Jul 23, 2:42 PM EDT | Severe Thunderstorm Warning | GYX | 33 min |
| Jul 23, 5:18 PM EDT | Severe Thunderstorm Warning | GYX | 42 min |
| Jul 23, 5:47 PM EDT | Mesoscale Discussion | SPC | 58 min |
| Jul 23, 6:25 PM EDT | Special Weather Statement | GYX | 35 min |
| Jul 25, 8:43 PM EDT | Special Weather Statement | GYX | 32 min |
| Jul 25, 9:16 PM EDT | Special Weather Statement | GYX | 29 min |
| Jul 29, 8:58 PM EDT | Areal Flood Advisory | GYX | 4 hr |
| Jul 29, 9:33 PM EDT | Flash Flood Warning | GYX | 5 hr |
| Aug 1, 3:51 AM EDT | Flash Flood Watch | GYX | 24 hr |
| Aug 1, 8:15 PM EDT | Flash Flood Warning | GYX | 6 hr |
| Aug 7, 7:40 PM EDT | Special Weather Statement | GYX | 35 min |
| Aug 8, 5:10 PM EDT | Areal Flood Advisory | GYX | 71 min |
| Aug 8, 8:10 PM EDT | Areal Flood Advisory | GYX | 79 min |
| Aug 10, 3:15 AM EDT | Heat Advisory | GYX | 4 days |
| Aug 10, 2:41 PM EDT | Heat Advisory | GYX | 53 hr |
| Aug 11, 4:57 PM EDT | Mesoscale Discussion | SPC | 93 min |
| Aug 18, 3:02 PM EDT | Flash Flood Watch | GYX | 31 hr |
| Aug 30, 3:19 PM EDT | Special Weather Statement | GYX | 26 min |
| Sep 2, 3:49 AM EDT | Areal Flood Advisory | GYX | 5 hr |
| Sep 6, 1:56 PM EDT | Special Weather Statement | GYX | 34 min |
| Sep 6, 3:02 PM EDT | Special Weather Statement | GYX | 43 min |
| Sep 8, 9:40 PM EDT | Special Weather Statement | GYX | 35 min |
| Sep 15, 11:59 AM EDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 15, 1:15 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Sep 15, 2:18 PM EDT | Severe Thunderstorm Warning | GYX | 57 min |
| Sep 15, 2:31 PM EDT | Severe Thunderstorm Warning | GYX | 59 min |
| Sep 15, 3:04 PM EDT | Severe Thunderstorm Warning | GYX | 56 min |
| Sep 15, 3:22 PM EDT | Severe Thunderstorm Warning | GYX | 53 min |
| Sep 15, 4:09 PM EDT | Severe Thunderstorm Warning | GYX | 51 min |
| Sep 15, 4:38 PM EDT | Mesoscale Discussion | SPC | 67 min |
| Sep 24, 2:14 PM EDT | Areal Flood Advisory | GYX | 3 hr |
| Oct 29, 3:22 PM EDT | Flash Flood Watch | GYX | 39 hr |
| Oct 31, 12:11 PM EDT | River Flood Warning | GYX | 3 hr |
| Nov 11, 2:52 PM EST | Wind Advisory | GYX | 29 hr |
| Nov 12, 3:48 AM EST | Flood Watch | GYX | 16 hr |
| Nov 12, 2:28 PM EST | Areal Flood Advisory | GYX | 3 hr |
| Nov 19, 1:08 PM EST | Special Weather Statement | GYX | 52 min |
| Nov 25, 2:55 PM EST | Winter Weather Advisory | GYX | 45 hr |
| Dec 3, 9:42 AM EST | Wind Advisory | GYX | 5 hr |
| Dec 4, 10:20 PM EST | Special Weather Statement | GYX | 40 min |
| Dec 10, 4:32 PM EST | Winter Weather Advisory | GYX | 26 hr |
| Dec 15, 2:55 AM EST | Winter Weather Advisory | GYX | 33 hr |
| Dec 16, 3:14 PM EST | Wind Advisory | GYX | 21 hr |
| Dec 17, 2:47 AM EST | Winter Storm Watch | GYX | 13 hr |
| Dec 17, 3:34 PM EST | Winter Storm Warning | GYX | 42 hr |
| Dec 21, 3:29 AM EST | Winter Weather Advisory | GYX | 36 hr |
| Dec 24, 3:26 AM EST | Winter Weather Advisory | GYX | 51 hr |
| Dec 25, 5:44 AM EST | Mesoscale Discussion | SPC | 5 hr |
| Dec 27, 3:11 PM EST | Winter Weather Advisory | GYX | 19 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 | 23 |
| Severe Thunderstorm Watch | 4 |
| Mesoscale Discussion | 16 |
| Special Weather Statement | 36 |
| Flooding | |
| Flash Flood Warning | 2 |
| River Flood Warning | 2 |
| Flash Flood Watch | 4 |
| Flood Watch | 2 |
| Areal Flood Advisory | 6 |
| Winter | |
| Winter Storm Warning | 4 |
| Winter Storm Watch | 4 |
| Winter Weather Advisory | 11 |
| Heat | |
| Heat Advisory | 5 |
| Cold | |
| Frost Advisory | 2 |
| Wind Chill Advisory | 4 |
| Wind and dust | |
| Wind Advisory | 5 |
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.