Alert archive / North Carolina / Alamance County
Weather alerts in Alamance County, North Carolina, 2017
117 weather alerts in 2017, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Alamance County and its neighbors
Each county as a circle sized by its count in 2017. Tap one for its archive.
- Alerts
- 117
- Warnings
- 25
- Watches
- 12
- Advisories
- 19
- Busiest month
- April23 alerts
- Busiest day
- April 6, 20178 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Alamance County, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 16 | 15 | 6% | 11 | 64% | 18 min |
| Flash flood warnings | 1 | 1 | 0% | 1 | 0% |
Each office's whole area, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Raleigh, NC: tornado warnings | 18 | 1 | 94% | 4 | 50% | 20 min |
| NWS Raleigh, NC: severe thunderstorm warnings | 211 | 135 | 36% | 418 | 89% | 21 min |
| NWS Raleigh, NC: flash flood warnings | 21 | 12 | 43% | 31 | 87% | 63 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 5, 8:29 AM EST | Winter Storm Watch | RAH | 20 hr |
| Jan 5, 3:42 PM EST | Winter Storm Warning | RAH | 48 hr |
| Jan 7, 2:21 AM EST | Special Weather Statement | RAH | 84 min |
| Jan 7, 3:18 AM EST | Mesoscale Discussion | SPC | 5 hr |
| Jan 7, 3:17 PM EST | Winter Weather Advisory | RAH | 69 hr |
| Jan 8, 4:02 AM EST | Wind Chill Advisory | RAH | 6 hr |
| Jan 11, 7:32 AM EST | Special Weather Statement | RAH | 73 min |
| Jan 21, 12:17 AM EST | Dense Fog Advisory | RAH | 10 hr |
| Feb 12, 3:29 PM EST | Mesoscale Discussion | SPC | 3 hr |
| Mar 1, 9:44 AM EST | Mesoscale Discussion | SPC | 91 min |
| Mar 1, 3:02 PM EST | Severe Thunderstorm Watch | SPC | 7 hr |
| Mar 1, 6:21 PM EST | Mesoscale Discussion | SPC | 114 min |
| Mar 1, 6:47 PM EST | Severe Thunderstorm Warning | RAH | 43 min |
| Mar 18, 3:26 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Mar 18, 5:46 PM EDT | Special Weather Statement | RAH | 59 min |
| Mar 28, 1:58 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Mar 31, 8:10 AM EDT | Special Weather Statement | RAH | 80 min |
| Mar 31, 2:08 PM EDT | Mesoscale Discussion | SPC | 67 min |
| Apr 3, 5:44 PM EDT | Severe Thunderstorm Warning | RAH | 46 min |
| Apr 3, 6:41 PM EDT | Mesoscale Discussion | SPC | 64 min |
| Apr 5, 2:53 PM EDT | Wind Advisory | RAH | 31 hr |
| Apr 6, 12:51 AM EDT | Mesoscale Discussion | SPC | 114 min |
| Apr 6, 2:54 AM EDT | Mesoscale Discussion | SPC | 96 min |
| Apr 6, 5:26 AM EDT | Severe Thunderstorm Warning | RAH | 49 min |
| Apr 6, 5:59 AM EDT | Mesoscale Discussion | SPC | 91 min |
| Apr 6, 6:45 AM EDT | Special Weather Statement | RAH | 45 min |
| Apr 6, 7:02 AM EDT | Special Weather Statement | RAH | 43 min |
| Apr 6, 7:06 AM EDT | Tornado Watch | SPC | 8 hr |
| Apr 6, 3:53 PM EDT | Wind Advisory | RAH | 26 hr |
| Apr 7, 9:32 PM EDT | Frost Advisory | RAH | 11 hr |
| Apr 8, 3:01 PM EDT | Frost Advisory | RAH | 18 hr |
| Apr 20, 3:53 AM EDT | Dense Fog Advisory | RAH | 5 hr |
| Apr 21, 4:11 PM EDT | Special Weather Statement | RAH | 64 min |
| Apr 21, 4:19 PM EDT | Mesoscale Discussion | SPC | 56 min |
| Apr 22, 3:17 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Apr 22, 4:11 PM EDT | Flood Watch | RAH | 64 hr |
| Apr 22, 4:12 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 23, 10:05 AM EDT | River Flood Warning | RAH | 3 days |
| Apr 24, 3:33 PM EDT | Areal Flood Advisory | RAH | 4 hr |
| Apr 24, 7:19 PM EDT | Areal Flood Warning | RAH | 6 hr |
| Apr 25, 1:16 AM EDT | Areal Flood Warning | RAH | 6 hr |
| May 1, 5:54 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| May 1, 6:49 PM EDT | Special Weather Statement | RAH | 56 min |
| May 1, 6:57 PM EDT | Severe Thunderstorm Warning | RAH | 51 min |
| May 1, 8:28 PM EDT | Mesoscale Discussion | SPC | 92 min |
| May 5, 2:28 AM EDT | Mesoscale Discussion | SPC | 92 min |
| May 5, 3:09 AM EDT | Tornado Watch | SPC | 6 hr |
| May 5, 3:32 AM EDT | Severe Thunderstorm Warning | RAH | 43 min |
| May 10, 5:16 AM EDT | Dense Fog Advisory | RAH | 4 hr |
| May 11, 4:47 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| May 11, 7:46 PM EDT | Severe Thunderstorm Watch | SPC | 3 hr |
| May 11, 8:03 PM EDT | Special Weather Statement | RAH | 57 min |
| May 19, 2:24 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| May 19, 4:37 PM EDT | Special Weather Statement | RAH | 53 min |
| May 19, 4:52 PM EDT | Severe Thunderstorm Warning | RAH | 38 min |
| May 22, 11:09 PM EDT | Areal Flood Advisory | RAH | 111 min |
| May 23, 3:41 AM EDT | Flood Watch | RAH | 41 hr |
| May 24, 3:13 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| May 24, 3:46 PM EDT | Tornado Watch | SPC | 6 hr |
| May 24, 3:57 PM EDT | Special Weather Statement | RAH | 78 min |
| May 25, 1:36 AM EDT | Special Weather Statement | RAH | 24 min |
| May 25, 12:10 PM EDT | Special Weather Statement | RAH | 80 min |
| May 31, 7:23 PM EDT | Severe Thunderstorm Warning | RAH | 42 min |
| Jun 4, 3:15 PM EDT | Mesoscale Discussion | SPC | 90 min |
| Jun 4, 4:44 PM EDT | Special Weather Statement | RAH | 46 min |
| Jun 13, 5:47 PM EDT | Special Weather Statement | RAH | 58 min |
| Jun 14, 1:17 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 16, 1:27 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 16, 6:52 PM EDT | Special Weather Statement | RAH | 53 min |
| Jun 18, 11:34 PM EDT | Special Weather Statement | RAH | 86 min |
| Jun 18, 11:59 PM EDT | Severe Thunderstorm Warning | RAH | 46 min |
| Jun 19, 6:43 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 19, 8:41 PM EDT | Special Weather Statement | RAH | 64 min |
| Jun 19, 8:55 PM EDT | Areal Flood Advisory | RAH | 6 hr |
| Jun 19, 10:14 PM EDT | Special Weather Statement | RAH | 46 min |
| Jun 19, 11:34 PM EDT | River Flood Warning | RAH | 29 hr |
| Jun 19, 11:39 PM EDT | Flash Flood Warning | RAH | 4 hr |
| Jun 20, 3:03 AM EDT | Areal Flood Warning | RAH | 3 hr |
| Jun 24, 1:14 AM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 24, 1:46 AM EDT | Severe Thunderstorm Warning | RAH | 59 min |
| Jun 24, 3:35 PM EDT | Special Weather Statement | RAH | 40 min |
| Jun 30, 1:02 PM EDT | Special Weather Statement | RAH | 73 min |
| Jul 5, 7:24 PM EDT | Special Weather Statement | RAH | 66 min |
| Jul 5, 8:28 PM EDT | Special Weather Statement | RAH | 62 min |
| Jul 5, 8:48 PM EDT | Severe Thunderstorm Warning | RAH | 42 min |
| Jul 6, 5:22 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Jul 8, 4:50 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Jul 13, 5:19 PM EDT | Severe Thunderstorm Warning | RAH | 56 min |
| Jul 13, 5:59 PM EDT | Severe Thunderstorm Warning | RAH | 58 min |
| Jul 18, 4:46 PM EDT | Special Weather Statement | RAH | 44 min |
| Jul 18, 5:16 PM EDT | Severe Thunderstorm Warning | RAH | 44 min |
| Jul 18, 8:07 PM EDT | Special Weather Statement | RAH | 68 min |
| Jul 21, 3:03 PM EDT | Heat Advisory | RAH | 52 hr |
| Jul 23, 11:36 AM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 23, 5:26 PM EDT | Severe Thunderstorm Warning | RAH | 64 min |
| Jul 23, 6:23 PM EDT | Areal Flood Advisory | RAH | 3 hr |
| Jul 27, 7:51 PM EDT | Special Weather Statement | RAH | 54 min |
| Jul 27, 8:34 PM EDT | Special Weather Statement | RAH | 56 min |
| Aug 8, 12:25 AM EDT | Special Weather Statement | RAH | 50 min |
| Aug 18, 7:19 PM EDT | Special Weather Statement | RAH | 26 min |
| Aug 18, 7:49 PM EDT | Special Weather Statement | RAH | 56 min |
| Aug 23, 1:23 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 1, 1:07 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Sep 1, 3:45 PM EDT | Severe Thunderstorm Warning | RAH | 45 min |
| Sep 1, 4:36 PM EDT | Areal Flood Advisory | RAH | 114 min |
| Sep 1, 4:44 PM EDT | Mesoscale Discussion | SPC | 91 min |
| Sep 1, 5:19 PM EDT | Severe Thunderstorm Warning | RAH | 41 min |
| Oct 8, 2:22 PM EDT | Special Weather Statement | RAH | 53 min |
| Oct 15, 5:21 AM EDT | Dense Fog Advisory | RAH | 6 hr |
| Oct 23, 5:40 PM EDT | Tornado Watch | SPC | 8 hr |
| Oct 23, 7:34 PM EDT | Mesoscale Discussion | SPC | 116 min |
| Nov 6, 2:52 AM EST | Dense Fog Advisory | RAH | 6 hr |
| Nov 9, 2:55 PM EST | Freeze Watch | RAH | 12 hr |
| Nov 10, 2:30 AM EST | Freeze Warning | RAH | 31 hr |
| Dec 8, 4:17 AM EST | Winter Weather Advisory | RAH | 35 hr |
| Dec 8, 2:48 PM EST | Winter Storm Warning | RAH | 25 hr |
| Dec 9, 3:24 PM EST | Winter Weather Advisory | RAH | 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 | 16 |
| Severe Thunderstorm Watch | 4 |
| Tornado Watch | 4 |
| Mesoscale Discussion | 30 |
| Special Weather Statement | 31 |
| Flooding | |
| Areal Flood Warning | 3 |
| Flash Flood Warning | 1 |
| River Flood Warning | 2 |
| Flood Watch | 2 |
| Areal Flood Advisory | 5 |
| Winter | |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 3 |
| Heat | |
| Heat Advisory | 1 |
| Cold | |
| Freeze Warning | 1 |
| Freeze Watch | 1 |
| Frost Advisory | 2 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| Wind Advisory | 2 |
| Fog and smoke | |
| Dense Fog Advisory | 5 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20162018
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.