Alert archive / Virginia / Alleghany County
Weather alerts in Alleghany County, Virginia, 2021
108 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Alleghany County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 108
- Warnings
- 20
- Watches
- 18
- Advisories
- 29
- Busiest month
- August22 alerts
- Busiest day
- April 9, 20217 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Alleghany County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 11 | 7 | 36% | 7 | 57% | 13 min |
| Flash flood warnings | 1 | 0 | 100% | 0 |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Blacksburg, VA: tornado warnings | 30 | 1 | 97% | 2 | 50% | 1 min |
| NWS Blacksburg, VA: severe thunderstorm warnings | 221 | 165 | 25% | 522 | 74% | 20 min |
| NWS Blacksburg, VA: flash flood warnings | 42 | 14 | 67% | 51 | 61% | 107 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 16, 1:09 AM EST | Freezing Fog Advisory | RNK | 8 hr |
| Jan 18, 9:59 AM EST | Special Weather Statement | RNK | 46 min |
| Jan 26, 12:15 AM EST | Areal Flood Warning | RNK | 12 hr |
| Jan 29, 3:12 PM EST | Winter Storm Watch | RNK | 14 hr |
| Jan 30, 5:19 AM EST | Winter Storm Warning | RNK | 33 hr |
| Jan 31, 5:12 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Jan 31, 2:14 PM EST | Winter Weather Advisory | RNK | 47 hr |
| Feb 1, 2:27 PM EST | Wind Advisory | RNK | 47 hr |
| Feb 4, 4:53 AM EST | Winter Weather Advisory | RNK | 28 hr |
| Feb 5, 11:53 AM EST | Winter Storm Watch | RNK | 16 hr |
| Feb 6, 4:16 AM EST | Winter Storm Warning | RNK | 32 hr |
| Feb 7, 4:24 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Feb 10, 3:40 AM EST | Winter Storm Watch | RNK | 24 hr |
| Feb 10, 3:40 AM EST | Winter Weather Advisory | RNK | 55 hr |
| Feb 11, 4:05 AM EST | Winter Weather Advisory | RNK | 31 hr |
| Feb 12, 3:47 AM EST | Winter Weather Advisory | RNK | 56 hr |
| Feb 12, 10:42 AM EST | Freezing Fog Advisory | RNK | 10 hr |
| Feb 14, 1:24 PM EST | Winter Weather Advisory | RNK | 21 hr |
| Feb 16, 5:07 AM EST | Winter Storm Watch | RNK | 23 hr |
| Feb 17, 4:25 AM EST | Winter Storm Warning | RNK | 47 hr |
| Feb 18, 4:28 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Feb 18, 11:51 AM EST | Winter Weather Advisory | RNK | 22 hr |
| Feb 25, 8:06 PM EST | Winter Weather Advisory | RNK | 30 hr |
| Feb 27, 4:46 AM EST | Flood Watch | RNK | 50 hr |
| Feb 28, 9:18 PM EST | Special Weather Statement | RNK | 27 min |
| Mar 1, 1:14 AM EST | Areal Flood Warning | RNK | 12 hr |
| Mar 1, 4:13 PM EST | Areal Flood Advisory | RNK | 9 hr |
| Mar 25, 4:45 AM EDT | Wind Advisory | RNK | 33 hr |
| Mar 28, 3:58 AM EDT | Wind Advisory | RNK | 22 hr |
| Mar 28, 2:12 PM EDT | Special Weather Statement | RNK | 63 min |
| Mar 28, 3:28 PM EDT | Special Weather Statement | RNK | 62 min |
| Mar 31, 2:13 PM EDT | Wind Advisory | RNK | 33 hr |
| Apr 8, 8:23 PM EDT | Severe Thunderstorm Warning | RNK | 37 min |
| Apr 8, 9:15 PM EDT | Areal Flood Advisory | RNK | 4 hr |
| Apr 8, 9:15 PM EDT | Special Weather Statement | RNK | 90 min |
| Apr 8, 9:27 PM EDT | Severe Thunderstorm Warning | RNK | 63 min |
| Apr 9, 1:37 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Apr 9, 2:05 PM EDT | Special Weather Statement | RNK | 25 min |
| Apr 9, 2:53 PM EDT | Special Weather Statement | RNK | 37 min |
| Apr 20, 3:23 AM EDT | Freeze Watch | RNK | 24 hr |
| Apr 21, 3:39 AM EDT | Freeze Warning | RNK | 29 hr |
| Apr 21, 9:48 PM EDT | Freeze Watch | RNK | 6 hr |
| Apr 22, 3:27 AM EDT | Freeze Warning | RNK | 30 hr |
| Apr 29, 2:47 PM EDT | Wind Advisory | RNK | 33 hr |
| May 4, 1:04 PM EDT | Mesoscale Discussion | SPC | 56 min |
| May 4, 1:51 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 4, 1:53 PM EDT | Special Weather Statement | RNK | 37 min |
| May 4, 2:15 PM EDT | Severe Thunderstorm Warning | RNK | 60 min |
| May 4, 3:05 PM EDT | Severe Thunderstorm Warning | RNK | 40 min |
| May 25, 3:17 PM EDT | Special Weather Statement | RNK | 43 min |
| Jun 7, 5:21 PM EDT | Special Weather Statement | RNK | 39 min |
| Jun 7, 6:08 PM EDT | Special Weather Statement | RNK | 37 min |
| Jun 7, 6:15 PM EDT | Areal Flood Advisory | RNK | 116 min |
| Jun 7, 7:30 PM EDT | Special Weather Statement | RNK | 30 min |
| Jun 7, 8:04 PM EDT | Flash Flood Warning | RNK | 4 hr |
| Jun 10, 1:14 PM EDT | Flash Flood Watch | RNK | 11 hr |
| Jun 10, 1:14 PM EDT | Flash Flood Watch | RNK | 33 hr |
| Jun 10, 7:50 PM EDT | Special Weather Statement | RNK | 25 min |
| Jun 10, 7:59 PM EDT | Areal Flood Advisory | RNK | 2 hr |
| Jun 11, 4:05 PM EDT | Areal Flood Advisory | RNK | 5 hr |
| Jun 11, 4:56 PM EDT | Areal Flood Advisory | RNK | 5 hr |
| Jun 13, 4:56 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 13, 5:54 PM EDT | Severe Thunderstorm Warning | RNK | 66 min |
| Jun 13, 7:05 PM EDT | Mesoscale Discussion | SPC | 85 min |
| Jun 13, 7:35 PM EDT | Severe Thunderstorm Warning | RNK | 55 min |
| Jun 13, 7:58 PM EDT | Severe Thunderstorm Warning | RNK | 32 min |
| Jul 1, 10:00 AM EDT | Flash Flood Watch | RNK | 21 hr |
| Jul 7, 2:15 PM EDT | Special Weather Statement | RNK | 30 min |
| Jul 7, 3:00 PM EDT | Special Weather Statement | RNK | 30 min |
| Jul 10, 4:42 PM EDT | Special Weather Statement | RNK | 63 min |
| Jul 13, 3:46 PM EDT | Special Weather Statement | RNK | 29 min |
| Jul 13, 6:00 PM EDT | Special Weather Statement | RNK | 45 min |
| Jul 17, 5:01 PM EDT | Special Weather Statement | RNK | 59 min |
| Aug 11, 1:01 PM EDT | Mesoscale Discussion | SPC | 89 min |
| Aug 12, 1:30 PM EDT | Special Weather Statement | RNK | 30 min |
| Aug 12, 2:15 PM EDT | Special Weather Statement | RNK | 30 min |
| Aug 13, 4:16 PM EDT | Special Weather Statement | RNK | 29 min |
| Aug 13, 4:41 PM EDT | Special Weather Statement | RNK | 34 min |
| Aug 13, 4:57 PM EDT | Severe Thunderstorm Warning | RNK | 47 min |
| Aug 14, 9:18 PM EDT | Special Weather Statement | RNK | 27 min |
| Aug 14, 9:53 PM EDT | Areal Flood Advisory | RNK | 89 min |
| Aug 17, 3:37 AM EDT | Flash Flood Watch | RNK | 24 hr |
| Aug 17, 2:53 PM EDT | Flood Watch | RNK | 12 min |
| Aug 20, 2:35 PM EDT | Special Weather Statement | RNK | 25 min |
| Aug 20, 3:01 PM EDT | Special Weather Statement | RNK | 44 min |
| Aug 26, 5:32 PM EDT | Special Weather Statement | RNK | 43 min |
| Aug 27, 3:53 AM EDT | Dense Fog Advisory | RNK | 6 hr |
| Aug 29, 2:21 PM EDT | Special Weather Statement | RNK | 24 min |
| Aug 29, 3:23 PM EDT | Severe Thunderstorm Warning | RNK | 67 min |
| Aug 29, 3:48 PM EDT | Special Weather Statement | RNK | 27 min |
| Aug 29, 4:01 PM EDT | Severe Thunderstorm Warning | RNK | 44 min |
| Aug 29, 4:42 PM EDT | Severe Thunderstorm Warning | RNK | 44 min |
| Aug 29, 7:40 PM EDT | Special Weather Statement | RNK | 35 min |
| Aug 30, 5:04 AM EDT | Flash Flood Watch | RNK | 60 hr |
| Aug 31, 7:36 PM EDT | Tornado Watch | SPC | 7 hr |
| Aug 31, 9:18 PM EDT | Special Weather Statement | RNK | 27 min |
| Aug 31, 9:47 PM EDT | Special Weather Statement | RNK | 28 min |
| Sep 1, 5:29 AM EDT | Areal Flood Advisory | RNK | 3 hr |
| Sep 21, 4:11 AM EDT | Flood Watch | RNK | 102 min |
| Sep 21, 5:59 AM EDT | Flash Flood Watch | RNK | 41 hr |
| Sep 22, 2:44 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 23, 12:15 AM EDT | Areal Flood Advisory | RNK | 8 hr |
| Sep 23, 5:54 AM EDT | Areal Flood Warning | RNK | 10 hr |
| Sep 23, 3:53 PM EDT | Areal Flood Advisory | RNK | 4 hr |
| Oct 25, 10:20 PM EDT | Wind Advisory | RNK | 25 hr |
| Nov 12, 12:56 AM EST | Special Weather Statement | RNK | 49 min |
| Dec 2, 2:33 PM EST | Wind Advisory | RNK | 13 hr |
| Dec 11, 3:02 AM EST | Wind Advisory | RNK | 25 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 | 11 |
| Severe Thunderstorm Watch | 2 |
| Tornado Watch | 1 |
| Mesoscale Discussion | 8 |
| Special Weather Statement | 33 |
| Flooding | |
| Areal Flood Warning | 3 |
| Flash Flood Warning | 1 |
| Flash Flood Watch | 6 |
| Flood Watch | 3 |
| Areal Flood Advisory | 10 |
| Winter | |
| Winter Storm Warning | 3 |
| Winter Storm Watch | 4 |
| Winter Weather Advisory | 8 |
| Cold | |
| Freeze Warning | 2 |
| Freeze Watch | 2 |
| Wind and dust | |
| Wind Advisory | 8 |
| Fog and smoke | |
| Dense Fog Advisory | 1 |
| Freezing Fog Advisory | 2 |
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.