Alert archive / South Dakota / Lyman County
Weather alerts in Lyman County, South Dakota, 2021
120 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Lyman County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 120
- Warnings
- 43
- Watches
- 19
- Advisories
- 30
- Busiest month
- July22 alerts
- Busiest day
- July 5, 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.
Lyman County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 15 | 6 | 60% | 7 | 29% | 11 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 Aberdeen, SD: tornado warnings | 21 | 5 | 76% | 17 | 35% | 19 min |
| NWS Aberdeen, SD: severe thunderstorm warnings | 170 | 101 | 41% | 220 | 76% | 20 min |
| NWS Aberdeen, SD: flash flood warnings | 4 | 1 | 75% | 1 | 100% | 104 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, Central Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 6, 8:46 PM CST | Dense Fog Advisory | ABR | 13 hr |
| Jan 12, 11:23 AM CST | High Wind Watch | ABR | 27 hr |
| Jan 13, 1:40 PM CST | Red Flag Warning | ABR | 27 hr |
| Jan 13, 2:37 PM CST | High Wind Warning | ABR | 45 hr |
| Jan 22, 2:15 AM CST | Winter Weather Advisory | ABR | 43 hr |
| Jan 29, 9:33 PM CST | Dense Fog Advisory | ABR | 13 hr |
| Jan 31, 8:55 PM CST | Dense Fog Advisory | ABR | 68 hr |
| Feb 10, 1:29 PM CST | Wind Chill Advisory | ABR | 3 days |
| Feb 12, 2:27 PM CST | Wind Chill Warning | ABR | 69 hr |
| Feb 15, 11:30 AM CST | Wind Chill Warning | ABR | 22 hr |
| Feb 21, 1:25 PM CST | Wind Advisory | ABR | 29 hr |
| Feb 27, 4:29 AM CST | Winter Weather Advisory | ABR | 26 hr |
| Mar 5, 2:30 AM CST | Dense Fog Advisory | ABR | 10 hr |
| Mar 5, 2:45 PM CST | Red Flag Warning | ABR | 29 hr |
| Mar 9, 4:07 AM CST | Winter Weather Advisory | ABR | 44 hr |
| Mar 14, 3:19 AM CDT | Winter Weather Advisory | ABR | 31 hr |
| Mar 14, 5:55 PM CDT | Winter Storm Warning | ABR | 16 hr |
| Mar 14, 6:20 PM CDT | Mesoscale Discussion | SPC | 6 hr |
| Mar 26, 2:41 PM CDT | Fire Weather Watch | ABR | 48 hr |
| Mar 28, 3:53 AM CDT | Red Flag Warning | ABR | 16 hr |
| Mar 28, 2:31 PM CDT | High Wind Warning | ABR | 28 hr |
| Mar 28, 2:31 PM CDT | Wind Advisory | ABR | 32 hr |
| Mar 28, 2:36 PM CDT | Red Flag Warning | ABR | 31 hr |
| Mar 29, 3:00 AM CDT | Fire Weather Watch | ABR | 23 hr |
| Mar 29, 9:04 PM CDT | High Wind Warning | ABR | 10 hr |
| Mar 29, 9:04 PM CDT | Wind Advisory | ABR | 21 hr |
| Mar 30, 2:14 AM CDT | Red Flag Warning | ABR | 18 hr |
| Mar 30, 6:11 PM CDT | Wind Advisory | ABR | 3 hr |
| Mar 31, 3:02 AM CDT | Fire Weather Watch | ABR | 12 hr |
| Mar 31, 2:48 PM CDT | Red Flag Warning | ABR | 31 hr |
| Apr 3, 3:15 AM CDT | Red Flag Warning | ABR | 17 hr |
| Apr 5, 3:32 AM CDT | Red Flag Warning | ABR | 16 hr |
| Apr 10, 2:43 PM CDT | Wind Advisory | ABR | 52 hr |
| May 23, 10:04 PM CDT | Severe Thunderstorm Warning | ABR | 41 min |
| May 23, 10:14 PM CDT | Severe Thunderstorm Warning | ABR | 46 min |
| Jun 10, 3:53 AM CDT | Heat Advisory | ABR | 16 hr |
| Jun 10, 8:28 PM CDT | Mesoscale Discussion | SPC | 92 min |
| Jun 10, 9:08 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 11, 12:52 AM CDT | Mesoscale Discussion | SPC | 53 min |
| Jun 13, 10:35 PM CDT | Special Weather Statement | ABR | 25 min |
| Jun 13, 11:10 PM CDT | Severe Thunderstorm Warning | ABR | 35 min |
| Jun 13, 11:44 PM CDT | Severe Thunderstorm Warning | ABR | 31 min |
| Jun 13, 11:53 PM CDT | Severe Thunderstorm Warning | ABR | 37 min |
| Jun 14, 12:23 AM CDT | Severe Thunderstorm Warning | ABR | 38 min |
| Jun 15, 2:09 PM CDT | Heat Advisory | ABR | 30 hr |
| Jun 20, 12:30 AM CDT | Special Weather Statement | ABR | 30 min |
| Jul 1, 2:17 PM CDT | Fire Weather Watch | ABR | 16 hr |
| Jul 2, 6:06 AM CDT | Red Flag Warning | ABR | 15 hr |
| Jul 3, 2:57 AM CDT | Red Flag Warning | ABR | 15 hr |
| Jul 3, 4:33 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 3, 6:33 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Jul 5, 1:30 PM CDT | Special Weather Statement | ABR | 45 min |
| Jul 5, 1:34 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jul 5, 1:44 PM CDT | Special Weather Statement | UNR | 16 min |
| Jul 5, 1:50 PM CDT | Severe Thunderstorm Warning | ABR | 40 min |
| Jul 5, 2:14 PM CDT | Special Weather Statement | UNR | 16 min |
| Jul 5, 2:30 PM CDT | Severe Thunderstorm Warning | ABR | 30 min |
| Jul 5, 2:37 PM CDT | Special Weather Statement | UNR | 23 min |
| Jul 5, 3:13 PM CDT | Areal Flood Warning | ABR | 6 hr |
| Jul 8, 8:54 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 8, 9:33 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 9, 2:41 AM CDT | Mesoscale Discussion | SPC | 34 min |
| Jul 25, 3:28 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 25, 6:43 PM CDT | Severe Thunderstorm Warning | ABR | 22 min |
| Jul 26, 3:41 AM CDT | Heat Advisory | ABR | 15 hr |
| Jul 26, 3:41 AM CDT | Heat Advisory | ABR | 41 hr |
| Jul 27, 3:42 AM CDT | Heat Advisory | ABR | 39 hr |
| Jul 31, 5:46 AM CDT | Dense Fog Advisory | ABR | 4 hr |
| Aug 6, 7:21 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 6, 9:09 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 6, 11:07 PM CDT | Severe Thunderstorm Warning | ABR | 38 min |
| Aug 6, 11:29 PM CDT | Severe Thunderstorm Warning | ABR | 46 min |
| Aug 10, 3:28 AM CDT | Red Flag Warning | ABR | 17 hr |
| Aug 16, 2:21 PM CDT | Fire Weather Watch | ABR | 12 hr |
| Aug 17, 2:39 AM CDT | Red Flag Warning | ABR | 17 hr |
| Aug 22, 3:36 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 23, 2:56 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 23, 5:20 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 23, 7:38 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 23, 8:33 PM CDT | Special Weather Statement | UNR | 42 min |
| Aug 23, 9:37 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Aug 26, 7:25 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 26, 8:03 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 30, 7:25 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 30, 9:57 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 30, 11:14 PM CDT | Severe Thunderstorm Warning | ABR | 20 min |
| Aug 30, 11:46 PM CDT | Areal Flood Warning | ABR | 37 min |
| Aug 31, 12:14 AM CDT | Flash Flood Warning | ABR | 6 hr |
| Aug 31, 12:33 AM CDT | Severe Thunderstorm Warning | ABR | 42 min |
| Sep 1, 6:26 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Sep 1, 9:20 PM CDT | Mesoscale Discussion | SPC | 85 min |
| Sep 1, 11:36 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Sep 13, 7:52 AM CDT | Special Weather Statement | UNR | 53 min |
| Sep 13, 9:00 AM CDT | Special Weather Statement | ABR | 30 min |
| Sep 13, 9:10 AM CDT | Severe Thunderstorm Warning | ABR | 23 min |
| Oct 9, 12:05 PM CDT | Severe Thunderstorm Warning | ABR | 27 min |
| Oct 9, 1:10 PM CDT | Special Weather Statement | UNR | 35 min |
| Oct 9, 1:57 PM CDT | Special Weather Statement | ABR | 33 min |
| Oct 9, 7:52 PM CDT | Special Weather Statement | ABR | 38 min |
| Oct 12, 3:55 PM CDT | Wind Advisory | ABR | 30 hr |
| Oct 13, 2:05 PM CDT | High Wind Warning | ABR | 8 hr |
| Oct 15, 11:38 AM CDT | Frost Advisory | ABR | 22 hr |
| Oct 28, 10:04 AM CDT | Wind Advisory | ABR | 7 hr |
| Nov 10, 9:49 AM CST | High Wind Watch | ABR | 5 hr |
| Nov 10, 2:45 PM CST | High Wind Warning | ABR | 39 hr |
| Nov 12, 3:02 AM CST | Wind Advisory | ABR | 9 hr |
| Nov 13, 3:26 AM CST | High Wind Warning | ABR | 20 hr |
| Nov 13, 2:14 PM CST | Wind Advisory | ABR | 3 hr |
| Nov 15, 2:47 PM CST | Wind Advisory | ABR | 51 hr |
| Nov 22, 2:40 PM CST | Fire Weather Watch | ABR | 12 hr |
| Nov 23, 2:15 AM CST | Red Flag Warning | ABR | 16 hr |
| Dec 4, 3:11 AM CST | High Wind Watch | ABR | 12 hr |
| Dec 4, 3:01 PM CST | High Wind Warning | ABR | 27 hr |
| Dec 9, 6:17 AM CST | Winter Weather Advisory | ABR | 39 hr |
| Dec 10, 2:11 AM CST | Winter Storm Warning | ABR | 16 hr |
| Dec 14, 3:37 AM CST | High Wind Watch | ABR | 11 hr |
| Dec 14, 3:54 AM CST | Winter Weather Advisory | ABR | 50 hr |
| Dec 14, 2:20 PM CST | High Wind Warning | ABR | 36 hr |
| Dec 26, 2:51 PM CST | Wind Advisory | ABR | 18 hr |
| Dec 30, 9:18 PM CST | Winter Weather Advisory | ABR | 15 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 | 15 |
| Severe Thunderstorm Watch | 9 |
| Mesoscale Discussion | 16 |
| Special Weather Statement | 12 |
| Flooding | |
| Areal Flood Warning | 2 |
| Flash Flood Warning | 1 |
| Winter | |
| Winter Storm Warning | 2 |
| Winter Weather Advisory | 7 |
| Heat | |
| Heat Advisory | 5 |
| Cold | |
| Wind Chill Warning | 2 |
| Frost Advisory | 1 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| High Wind Warning | 8 |
| High Wind Watch | 4 |
| Wind Advisory | 11 |
| Fire | |
| Red Flag Warning | 13 |
| Fire Weather Watch | 6 |
| 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 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.