Alert archive / Virginia / Montgomery County
Weather alerts in Montgomery County, Virginia, 2020
169 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Montgomery County and its neighbors
Each county as a circle sized by its count in 2020. Tap one for its archive.
- Alerts
- 169
- Warnings
- 48
- Watches
- 22
- Advisories
- 49
- Busiest month
- August32 alerts
- Busiest day
- April 8, 20209 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
0 of 1 tornado warnings covering Montgomery County in 2020 had a tornado report inside them.
Montgomery County, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 1 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 16 | 12 | 25% | 15 | 53% | 17 min |
| Flash flood warnings | 4 | 3 | 25% | 6 | 67% | 145 min |
Each office's whole area, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Blacksburg, VA: tornado warnings | 11 | 0 | 100% | 1 | 0% | |
| NWS Blacksburg, VA: severe thunderstorm warnings | 175 | 134 | 23% | 447 | 74% | 20 min |
| NWS Blacksburg, VA: flash flood warnings | 81 | 53 | 35% | 206 | 68% | 95 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 4, 3:42 AM EST | Wind Advisory | RNK | 30 hr |
| Jan 6, 3:35 AM EST | Winter Weather Advisory | RNK | 34 hr |
| Jan 7, 8:49 AM EST | Mesoscale Discussion | SPC | 4 hr |
| Jan 7, 2:07 PM EST | Wind Advisory | RNK | 28 hr |
| Jan 10, 2:43 PM EST | Wind Advisory | RNK | 37 hr |
| Jan 11, 7:37 PM EST | Severe Thunderstorm Watch | SPC | 5 hr |
| Jan 11, 8:44 PM EST | Severe Thunderstorm Warning | RNK | 61 min |
| Jan 11, 9:07 PM EST | Severe Thunderstorm Warning | RNK | 53 min |
| Jan 11, 9:26 PM EST | Severe Thunderstorm Warning | RNK | 64 min |
| Jan 11, 9:43 PM EST | Severe Thunderstorm Warning | RNK | 62 min |
| Jan 15, 2:30 PM EST | Wind Advisory | RNK | 34 hr |
| Jan 17, 3:53 AM EST | Winter Weather Advisory | RNK | 35 hr |
| Jan 23, 3:17 PM EST | Winter Weather Advisory | RNK | 20 hr |
| Jan 24, 6:15 PM EST | Special Weather Statement | RNK | 30 min |
| Jan 24, 6:44 PM EST | Special Weather Statement | RNK | 61 min |
| Feb 2, 9:15 AM EST | Wind Advisory | RNK | 15 hr |
| Feb 5, 4:46 AM EST | Flood Watch | RNK | 49 hr |
| Feb 6, 9:40 PM EST | Wind Advisory | RNK | 20 hr |
| Feb 7, 3:35 AM EST | Areal Flood Advisory | RNK | 3 hr |
| Feb 7, 4:30 AM EST | Winter Weather Advisory | RNK | 20 hr |
| Feb 7, 6:27 AM EST | Areal Flood Advisory | RNK | 3 hr |
| Feb 7, 9:37 AM EST | Areal Flood Warning | RNK | 3 hr |
| Feb 7, 11:06 AM EST | River Flood Warning | RNK | 22 hr |
| Feb 7, 12:25 PM EST | Areal Flood Warning | RNK | 6 hr |
| Feb 12, 11:50 PM EST | Special Weather Statement | RNK | 115 min |
| Feb 26, 3:36 AM EST | Wind Advisory | RNK | 39 hr |
| Feb 26, 2:49 PM EST | Mesoscale Discussion | SPC | 116 min |
| Feb 26, 5:32 PM EST | Special Weather Statement | RNK | 28 min |
| Mar 5, 8:34 PM EST | Wind Advisory | RNK | 36 hr |
| Mar 13, 7:53 AM EDT | Special Weather Statement | RNK | 22 min |
| Apr 6, 1:59 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 7, 1:22 PM EDT | Special Weather Statement | RNK | 23 min |
| Apr 7, 2:07 PM EDT | Mesoscale Discussion | SPC | 53 min |
| Apr 8, 12:39 PM EDT | Mesoscale Discussion | SPC | 96 min |
| Apr 8, 1:10 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Apr 8, 3:09 PM EDT | Severe Thunderstorm Warning | RNK | 66 min |
| Apr 8, 3:37 PM EDT | Tornado Warning | RNK | 18 min |
| Apr 8, 4:02 PM EDT | Severe Thunderstorm Warning | RNK | 58 min |
| Apr 8, 4:05 PM EDT | Mesoscale Discussion | SPC | 85 min |
| Apr 8, 4:22 PM EDT | Severe Thunderstorm Warning | RNK | 23 min |
| Apr 8, 4:42 PM EDT | Severe Thunderstorm Warning | RNK | 33 min |
| Apr 8, 5:07 PM EDT | Severe Thunderstorm Warning | RNK | 23 min |
| Apr 9, 12:50 AM EDT | Mesoscale Discussion | SPC | 115 min |
| Apr 9, 1:47 AM EDT | Wind Advisory | RNK | 18 hr |
| Apr 9, 2:03 AM EDT | Severe Thunderstorm Watch | SPC | 3 hr |
| Apr 9, 3:36 AM EDT | Mesoscale Discussion | SPC | 84 min |
| Apr 9, 3:48 AM EDT | Special Weather Statement | RNK | 57 min |
| Apr 9, 9:27 PM EDT | Wind Advisory | RNK | 21 hr |
| Apr 12, 4:09 AM EDT | Flash Flood Watch | RNK | 27 hr |
| Apr 12, 2:18 PM EDT | Wind Advisory | RNK | 26 hr |
| Apr 13, 12:44 AM EDT | Areal Flood Advisory | RNK | 12 hr |
| Apr 13, 1:39 AM EDT | Special Weather Statement | RNK | 36 min |
| Apr 13, 3:47 AM EDT | Flash Flood Warning | RNK | 6 hr |
| Apr 13, 9:55 AM EDT | Areal Flood Warning | RNK | 6 hr |
| Apr 13, 11:40 AM EDT | River Flood Warning | RNK | 43 hr |
| Apr 21, 3:25 AM EDT | Wind Advisory | RNK | 19 hr |
| Apr 29, 4:44 AM EDT | Flood Watch | RNK | 29 hr |
| May 7, 4:57 AM EDT | Freeze Watch | RNK | 22 hr |
| May 8, 2:53 AM EDT | Freeze Warning | RNK | 31 hr |
| May 8, 1:52 PM EDT | Freeze Watch | RNK | 13 hr |
| May 9, 3:00 AM EDT | Freeze Warning | RNK | 31 hr |
| May 10, 2:14 PM EDT | Freeze Watch | RNK | 13 hr |
| May 11, 2:50 AM EDT | Freeze Warning | RNK | 28 hr |
| May 18, 2:23 PM EDT | Flash Flood Watch | RNK | 3 days |
| May 20, 5:17 AM EDT | Areal Flood Advisory | RNK | 4 hr |
| May 20, 11:27 AM EDT | Areal Flood Advisory | RNK | 4 hr |
| May 20, 11:28 AM EDT | River Flood Warning | RNK | 63 hr |
| May 20, 1:18 PM EDT | Areal Flood Warning | RNK | 12 hr |
| May 20, 3:28 PM EDT | Areal Flood Warning | RNK | 12 hr |
| May 21, 3:14 AM EDT | Areal Flood Warning | RNK | 9 hr |
| May 21, 12:07 PM EDT | Areal Flood Warning | RNK | 12 hr |
| May 21, 8:07 PM EDT | Flash Flood Watch | RNK | 23 hr |
| May 21, 11:59 PM EDT | Areal Flood Warning | RNK | 6 hr |
| May 22, 3:50 AM EDT | Dense Fog Advisory | RNK | 5 hr |
| May 22, 5:59 AM EDT | Areal Flood Warning | RNK | 6 hr |
| May 22, 11:41 AM EDT | Areal Flood Warning | RNK | 4 hr |
| May 23, 2:56 AM EDT | Dense Fog Advisory | RNK | 6 hr |
| May 24, 1:44 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| May 24, 5:17 PM EDT | Special Weather Statement | RNK | 43 min |
| May 24, 5:47 PM EDT | Areal Flood Advisory | RNK | 2 hr |
| May 27, 3:25 AM EDT | Flash Flood Watch | RNK | 23 hr |
| May 28, 9:07 AM EDT | River Flood Warning | RNK | 24 hr |
| May 28, 3:30 PM EDT | Severe Thunderstorm Warning | RNK | 38 min |
| Jun 4, 2:21 PM EDT | Special Weather Statement | RNK | 24 min |
| Jun 5, 5:08 AM EDT | Flash Flood Watch | RNK | 15 hr |
| Jun 5, 2:56 PM EDT | Special Weather Statement | RNK | 34 min |
| Jun 5, 6:26 PM EDT | Special Weather Statement | RNK | 49 min |
| Jun 14, 12:34 PM EDT | Mesoscale Discussion | SPC | 116 min |
| Jun 15, 12:10 AM EDT | Areal Flood Advisory | RNK | 3 hr |
| Jun 17, 7:43 AM EDT | Areal Flood Advisory | RNK | 83 min |
| Jun 17, 9:04 AM EDT | Areal Flood Warning | RNK | 5 hr |
| Jun 17, 2:16 PM EDT | Areal Flood Warning | RNK | 6 hr |
| Jun 17, 3:50 PM EDT | Areal Flood Warning | RNK | 6 hr |
| Jun 17, 6:00 PM EDT | Areal Flood Advisory | RNK | 8 hr |
| Jun 17, 8:14 PM EDT | Areal Flood Warning | RNK | 17 hr |
| Jun 18, 6:25 AM EDT | Areal Flood Advisory | RNK | 4 hr |
| Jun 20, 12:47 PM EDT | Flash Flood Watch | RNK | 8 hr |
| Jul 13, 2:10 AM EDT | Special Weather Statement | RNK | 35 min |
| Jul 16, 4:46 PM EDT | Special Weather Statement | RNK | 29 min |
| Jul 17, 1:47 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Jul 19, 4:05 PM EDT | Severe Thunderstorm Warning | RNK | 55 min |
| Jul 20, 12:57 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 21, 1:00 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 21, 1:45 PM EDT | Special Weather Statement | RNK | 30 min |
| Jul 21, 8:44 PM EDT | Special Weather Statement | RNK | 31 min |
| Jul 23, 1:11 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 26, 8:52 PM EDT | Special Weather Statement | RNK | 38 min |
| Jul 26, 9:22 PM EDT | Areal Flood Advisory | RNK | 3 hr |
| Jul 30, 8:26 PM EDT | Special Weather Statement | RNK | 34 min |
| Jul 30, 9:15 PM EDT | Special Weather Statement | RNK | 30 min |
| Aug 2, 4:55 AM EDT | Flash Flood Watch | RNK | 50 hr |
| Aug 2, 2:18 PM EDT | Mesoscale Discussion | SPC | 57 min |
| Aug 2, 6:59 PM EDT | Areal Flood Advisory | RNK | 63 min |
| Aug 3, 12:33 PM EDT | Areal Flood Advisory | RNK | 3 hr |
| Aug 3, 12:41 PM EDT | Special Weather Statement | RNK | 64 min |
| Aug 5, 5:22 PM EDT | Special Weather Statement | RNK | 23 min |
| Aug 5, 5:51 PM EDT | Special Weather Statement | RNK | 24 min |
| Aug 5, 6:02 PM EDT | Severe Thunderstorm Warning | RNK | 43 min |
| Aug 6, 1:58 PM EDT | Severe Thunderstorm Warning | RNK | 47 min |
| Aug 6, 2:02 PM EDT | Severe Thunderstorm Warning | RNK | 43 min |
| Aug 6, 2:08 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 6, 2:14 PM EDT | Areal Flood Advisory | RNK | 3 min |
| Aug 6, 2:17 PM EDT | Flash Flood Warning | RNK | 3 hr |
| Aug 6, 2:37 PM EDT | Severe Thunderstorm Warning | RNK | 38 min |
| Aug 12, 1:15 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 13, 2:50 AM EDT | Flash Flood Watch | RNK | 21 hr |
| Aug 13, 8:17 PM EDT | Areal Flood Advisory | RNK | 3 hr |
| Aug 13, 8:37 PM EDT | Flash Flood Warning | RNK | 3 hr |
| Aug 13, 8:50 PM EDT | Flash Flood Warning | RNK | 3 hr |
| Aug 13, 9:22 PM EDT | Areal Flood Advisory | RNK | 3 hr |
| Aug 14, 3:48 AM EDT | Flash Flood Watch | RNK | 41 hr |
| Aug 15, 5:36 PM EDT | Areal Flood Advisory | RNK | 3 hr |
| Aug 21, 4:15 AM EDT | Flash Flood Watch | RNK | 26 hr |
| Aug 22, 6:15 PM EDT | Special Weather Statement | RNK | 45 min |
| Aug 23, 4:04 PM EDT | Special Weather Statement | RNK | 41 min |
| Aug 24, 6:04 AM EDT | Dense Fog Advisory | RNK | 3 hr |
| Aug 25, 3:34 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 25, 7:07 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Aug 25, 8:50 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Aug 28, 2:13 PM EDT | Flash Flood Watch | RNK | 10 hr |
| Aug 28, 7:50 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 31, 2:36 PM EDT | Areal Flood Advisory | RNK | 114 min |
| Sep 29, 12:36 PM EDT | Areal Flood Advisory | RNK | 3 hr |
| Oct 2, 1:50 PM EDT | Frost Advisory | RNK | 19 hr |
| Oct 11, 4:43 AM EDT | Areal Flood Advisory | RNK | 4 hr |
| Oct 16, 2:17 PM EDT | Frost Advisory | RNK | 20 hr |
| Oct 17, 1:59 PM EDT | Frost Advisory | RNK | 19 hr |
| Oct 28, 5:33 AM EDT | Flood Watch | RNK | 32 hr |
| Oct 29, 9:59 AM EDT | Areal Flood Advisory | RNK | 3 hr |
| Nov 1, 3:33 AM EST | Wind Advisory | RNK | 32 hr |
| Nov 11, 12:22 PM EST | Areal Flood Advisory | RNK | 3 hr |
| Nov 11, 6:40 PM EST | Special Weather Statement | RNK | 50 min |
| Nov 11, 6:57 PM EST | Severe Thunderstorm Warning | RNK | 48 min |
| Nov 11, 7:01 PM EST | Areal Flood Warning | RNK | 6 hr |
| Nov 12, 1:21 AM EST | Areal Flood Warning | RNK | 15 hr |
| Nov 12, 6:55 AM EST | River Flood Warning | RNK | 21 hr |
| Nov 12, 3:37 PM EST | Areal Flood Warning | RNK | 6 hr |
| Nov 12, 9:32 PM EST | Areal Flood Warning | RNK | 8 hr |
| Nov 14, 2:06 PM EST | Wind Advisory | RNK | 44 hr |
| Dec 4, 10:11 PM EST | Special Weather Statement | RNK | 49 min |
| Dec 14, 2:26 PM EST | Winter Storm Watch | RNK | 14 hr |
| Dec 15, 4:35 AM EST | Winter Storm Warning | RNK | 41 hr |
| Dec 16, 6:36 AM EST | Mesoscale Discussion | SPC | 4 hr |
| Dec 16, 7:33 AM EST | Special Weather Statement | RNK | 117 min |
| Dec 16, 5:10 PM EST | Special Weather Statement | RNK | 35 min |
| Dec 21, 5:05 AM EST | Wind Advisory | RNK | 31 hr |
| Dec 23, 2:51 PM EST | Winter Weather Advisory | RNK | 48 hr |
| Dec 24, 7:31 PM EST | Special Weather Statement | RNK | 89 min |
| Dec 25, 3:17 PM EST | Wind Chill Advisory | RNK | 18 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 |
| Tornado Warning | 1 |
| Severe Thunderstorm Watch | 4 |
| Mesoscale Discussion | 21 |
| Special Weather Statement | 29 |
| Flooding | |
| Areal Flood Warning | 18 |
| Flash Flood Warning | 4 |
| River Flood Warning | 5 |
| Flash Flood Watch | 11 |
| Flood Watch | 3 |
| Areal Flood Advisory | 22 |
| Winter | |
| Winter Storm Warning | 1 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 5 |
| Cold | |
| Freeze Warning | 3 |
| Freeze Watch | 3 |
| Frost Advisory | 3 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| Wind Advisory | 15 |
| Fog and smoke | |
| Dense Fog Advisory | 3 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20192021
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.