Alert archive / Virginia / Shenandoah County
Weather alerts in Shenandoah County, Virginia, 2020
116 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Shenandoah County and its neighbors
Each county as a circle sized by its count in 2020. Tap one for its archive.
- Alerts
- 116
- Warnings
- 29
- Watches
- 28
- Advisories
- 31
- Busiest month
- April22 alerts
- Busiest day
- July 22, 20207 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Shenandoah County, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 16 | 9 | 44% | 0 | ||
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Baltimore/Washington: tornado warnings | 27 | 6 | 78% | 15 | 47% | 9 min |
| NWS Baltimore/Washington: severe thunderstorm warnings | 456 | 314 | 31% | 1,047 | 79% | 23 min |
| NWS Baltimore/Washington: flash flood warnings | 66 | 34 | 48% | 130 | 90% | 72 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, 1:49 PM EST | Winter Weather Advisory | LWX | 29 hr |
| Jan 7, 8:49 AM EST | Mesoscale Discussion | SPC | 4 hr |
| Jan 8, 3:40 AM EST | Wind Advisory | LWX | 13 hr |
| Jan 14, 10:41 PM EST | Dense Fog Advisory | LWX | 10 hr |
| Jan 15, 2:50 PM EST | Wind Advisory | LWX | 22 hr |
| Jan 17, 1:33 PM EST | Winter Weather Advisory | LWX | 29 hr |
| Feb 1, 1:28 AM EST | Dense Fog Advisory | LWX | 9 hr |
| Feb 26, 2:49 PM EST | Mesoscale Discussion | SPC | 116 min |
| Mar 3, 4:27 PM EST | Mesoscale Discussion | SPC | 2 hr |
| Mar 3, 10:28 PM EST | Severe Thunderstorm Warning | LWX | 30 min |
| Mar 3, 10:52 PM EST | Mesoscale Discussion | SPC | 113 min |
| Mar 29, 3:32 AM EDT | Dense Fog Advisory | LWX | 7 hr |
| Apr 7, 2:57 PM EDT | Mesoscale Discussion | SPC | 93 min |
| Apr 8, 3:53 AM EDT | Mesoscale Discussion | SPC | 97 min |
| Apr 8, 8:13 PM EDT | Wind Advisory | LWX | 23 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, 7:38 PM EDT | Wind Advisory | LWX | 22 hr |
| Apr 9, 7:47 PM EDT | Freeze Watch | LWX | 19 hr |
| Apr 10, 2:28 PM EDT | Freeze Warning | LWX | 19 hr |
| Apr 12, 12:35 PM EDT | Wind Advisory | LWX | 29 hr |
| Apr 13, 10:34 AM EDT | Mesoscale Discussion | SPC | 86 min |
| Apr 13, 12:27 PM EDT | Severe Thunderstorm Warning | LWX | 36 min |
| Apr 15, 3:13 AM EDT | Freeze Watch | LWX | 10 hr |
| Apr 15, 1:09 PM EDT | Freeze Watch | LWX | 24 hr |
| Apr 15, 1:09 PM EDT | Freeze Warning | LWX | 18 hr |
| Apr 16, 1:19 PM EDT | Freeze Warning | LWX | 20 hr |
| Apr 17, 7:20 PM EDT | Freeze Watch | LWX | 18 hr |
| Apr 18, 1:19 PM EDT | Frost Advisory | LWX | 20 hr |
| Apr 18, 9:22 PM EDT | Freeze Warning | LWX | 12 hr |
| Apr 21, 4:04 AM EDT | Freeze Warning | LWX | 27 hr |
| Apr 29, 4:24 AM EDT | Flood Watch | LWX | 39 hr |
| Apr 29, 5:08 AM EDT | Dense Fog Advisory | LWX | 3 hr |
| Apr 30, 11:25 AM EDT | Areal Flood Warning | LWX | 7 hr |
| May 3, 7:35 PM EDT | Flash Flood Watch | LWX | 5 hr |
| May 7, 4:29 AM EDT | Freeze Watch | LWX | 10 hr |
| May 7, 2:16 PM EDT | Freeze Warning | LWX | 43 hr |
| May 8, 3:30 AM EDT | Freeze Watch | LWX | 24 hr |
| May 9, 3:36 AM EDT | Freeze Warning | LWX | 28 hr |
| May 11, 3:43 AM EDT | Frost Advisory | LWX | 26 hr |
| May 12, 2:41 PM EDT | Frost Advisory | LWX | 18 hr |
| May 23, 4:09 AM EDT | Dense Fog Advisory | LWX | 4 hr |
| May 29, 12:27 PM EDT | Mesoscale Discussion | SPC | 63 min |
| May 29, 8:52 PM EDT | Severe Thunderstorm Warning | LWX | 24 min |
| Jun 3, 3:10 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 4, 2:02 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Jun 4, 2:29 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 4, 4:41 PM EDT | Mesoscale Discussion | SPC | 94 min |
| Jun 4, 5:07 PM EDT | Severe Thunderstorm Warning | LWX | 38 min |
| Jun 4, 5:43 PM EDT | Severe Thunderstorm Warning | LWX | 47 min |
| Jun 4, 10:44 PM EDT | Areal Flood Warning | LWX | 6 hr |
| Jun 4, 10:51 PM EDT | Flash Flood Watch | LWX | 4 hr |
| Jun 5, 3:40 AM EDT | Flash Flood Watch | LWX | 17 hr |
| Jun 5, 3:19 PM EDT | Severe Thunderstorm Warning | LWX | 41 min |
| Jun 6, 6:07 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Jun 20, 10:45 AM EDT | Flash Flood Watch | LWX | 10 hr |
| Jun 22, 1:58 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 22, 2:30 PM EDT | Severe Thunderstorm Warning | LWX | 30 min |
| Jun 23, 3:08 AM EDT | Dense Fog Advisory | LWX | 6 hr |
| Jun 25, 1:48 PM EDT | Mesoscale Discussion | SPC | 117 min |
| Jul 6, 12:33 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 8, 5:30 AM EDT | Dense Fog Advisory | LWX | 3 hr |
| Jul 18, 2:59 PM EDT | Heat Advisory | LWX | 29 hr |
| Jul 19, 2:47 PM EDT | Heat Advisory | LWX | 29 hr |
| Jul 20, 5:26 PM EDT | Severe Thunderstorm Warning | LWX | 33 min |
| Jul 21, 1:00 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 21, 1:38 PM EDT | Severe Thunderstorm Warning | LWX | 30 min |
| Jul 21, 2:01 PM EDT | Mesoscale Discussion | SPC | 59 min |
| Jul 22, 12:07 AM EDT | Heat Advisory | LWX | 18 hr |
| Jul 22, 10:48 AM EDT | Mesoscale Discussion | SPC | 117 min |
| Jul 22, 12:01 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 22, 1:18 PM EDT | Severe Thunderstorm Warning | LWX | 42 min |
| Jul 22, 1:36 PM EDT | Flash Flood Watch | LWX | 4 hr |
| Jul 22, 1:48 PM EDT | Severe Thunderstorm Warning | LWX | 42 min |
| Jul 22, 1:50 PM EDT | Severe Thunderstorm Warning | LWX | 40 min |
| Jul 30, 10:01 PM EDT | Flash Flood Watch | LWX | 20 hr |
| Aug 1, 4:00 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 1, 6:42 PM EDT | Severe Thunderstorm Warning | LWX | 17 min |
| Aug 1, 6:53 PM EDT | Flash Flood Watch | LWX | 7 hr |
| Aug 1, 7:05 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Aug 2, 3:28 PM EDT | Flash Flood Watch | LWX | 45 hr |
| Aug 5, 10:51 PM EDT | Flash Flood Watch | LWX | 25 hr |
| Aug 11, 3:19 PM EDT | Flash Flood Watch | LWX | 52 hr |
| Aug 12, 1:15 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 13, 1:49 AM EDT | Flash Flood Watch | LWX | 19 hr |
| Aug 25, 3:10 PM EDT | Mesoscale Discussion | SPC | 95 min |
| Aug 25, 3:34 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 25, 5:41 PM EDT | Severe Thunderstorm Warning | LWX | 49 min |
| Aug 25, 7:07 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Aug 28, 4:59 PM EDT | Flash Flood Watch | LWX | 11 hr |
| Aug 28, 6:30 PM EDT | Severe Thunderstorm Warning | LWX | 45 min |
| Aug 28, 7:50 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 28, 7:54 PM EDT | Areal Flood Warning | LWX | 47 min |
| Aug 30, 7:21 PM EDT | Flood Watch | LWX | 26 hr |
| Sep 3, 3:06 PM EDT | Mesoscale Discussion | SPC | 114 min |
| Sep 19, 1:37 PM EDT | Frost Advisory | LWX | 20 hr |
| Sep 20, 1:43 PM EDT | Frost Advisory | LWX | 19 hr |
| Sep 20, 8:55 PM EDT | Freeze Warning | LWX | 5 hr |
| Sep 21, 1:31 PM EDT | Frost Advisory | LWX | 19 hr |
| Sep 26, 11:55 PM EDT | Dense Fog Advisory | LWX | 10 hr |
| Sep 27, 10:10 AM EDT | Dense Fog Advisory | LWX | 50 min |
| Oct 2, 12:48 PM EDT | Frost Advisory | LWX | 20 hr |
| Oct 15, 4:44 PM EDT | Freeze Watch | LWX | 22 hr |
| Oct 16, 2:39 PM EDT | Frost Advisory | LWX | 19 hr |
| Oct 17, 2:25 PM EDT | Frost Advisory | LWX | 20 hr |
| Oct 28, 3:05 PM EDT | Flood Watch | LWX | 25 hr |
| Nov 14, 2:06 PM EST | Wind Advisory | LWX | 41 hr |
| Nov 15, 5:00 PM EST | Severe Thunderstorm Warning | LWX | 60 min |
| Dec 13, 2:25 PM EST | Winter Weather Advisory | LWX | 23 hr |
| Dec 14, 4:43 AM EST | Winter Storm Watch | LWX | 35 hr |
| Dec 15, 4:09 AM EST | Winter Storm Warning | LWX | 46 hr |
| Dec 16, 8:38 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Dec 16, 1:57 PM EST | Mesoscale Discussion | SPC | 5 hr |
| Dec 18, 5:27 AM EST | Dense Fog Advisory | LWX | 14 hr |
| Dec 23, 4:27 AM EST | Flash Flood Watch | LWX | 47 hr |
| Dec 25, 3:36 AM EST | Areal Flood Warning | LWX | 6 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 |
| Mesoscale Discussion | 28 |
| Flooding | |
| Areal Flood Warning | 4 |
| Flash Flood Watch | 13 |
| Flood Watch | 3 |
| Winter | |
| Winter Storm Warning | 1 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 3 |
| Heat | |
| Heat Advisory | 3 |
| Cold | |
| Freeze Warning | 8 |
| Freeze Watch | 7 |
| Frost Advisory | 9 |
| Wind and dust | |
| Wind Advisory | 6 |
| Fog and smoke | |
| Dense Fog Advisory | 10 |
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.