Alert archive / South Dakota / Davison County
Weather alerts in Davison County, South Dakota, 2018
88 weather alerts in 2018, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Davison County and its neighbors
Each county as a circle sized by its count in 2018. Tap one for its archive.
- Alerts
- 88
- Warnings
- 22
- Watches
- 15
- Advisories
- 31
- Busiest month
- June11 alerts
- Busiest day
- June 27, 20185 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Davison County, 2018
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 9 | 4 | 56% | 2 | 50% | 30 min |
| Flash flood warnings | 2 | 2 | 0% | 0 |
Each office's whole area, 2018
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Sioux Falls, SD: tornado warnings | 12 | 3 | 75% | 10 | 40% | 9 min |
| NWS Sioux Falls, SD: severe thunderstorm warnings | 165 | 77 | 53% | 157 | 81% | 19 min |
| NWS Sioux Falls, SD: flash flood warnings | 43 | 31 | 28% | 66 | 82% | 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 1, 12:01 PM CST | Wind Chill Advisory | FSD | 22 hr |
| Jan 9, 3:46 AM CST | Winter Storm Watch | FSD | 35 hr |
| Jan 10, 3:07 AM CST | Winter Weather Advisory | FSD | 38 hr |
| Jan 11, 12:12 PM CST | Wind Chill Advisory | FSD | 22 hr |
| Jan 14, 3:20 AM CST | Wind Chill Advisory | FSD | 56 hr |
| Jan 19, 4:20 AM CST | Winter Storm Watch | FSD | 47 hr |
| Jan 21, 3:41 AM CST | Winter Weather Advisory | FSD | 38 hr |
| Feb 7, 3:41 PM CST | Winter Weather Advisory | FSD | 35 hr |
| Feb 9, 3:07 PM CST | Wind Chill Advisory | FSD | 19 hr |
| Feb 18, 3:39 PM CST | Winter Weather Advisory | FSD | 42 hr |
| Feb 20, 2:06 PM CST | Wind Chill Advisory | FSD | 20 hr |
| Feb 21, 2:59 PM CST | Winter Weather Advisory | FSD | 33 hr |
| Feb 23, 3:00 PM CST | Winter Weather Advisory | FSD | 27 hr |
| Feb 23, 10:16 PM CST | Dense Fog Advisory | FSD | 11 hr |
| Mar 3, 4:20 AM CST | Winter Storm Watch | FSD | 34 hr |
| Mar 4, 4:09 AM CST | Blizzard Warning | FSD | 59 hr |
| Mar 15, 3:48 AM CDT | Winter Weather Advisory | FSD | 45 hr |
| Mar 16, 4:04 AM CDT | Mesoscale Discussion | SPC | 4 hr |
| Mar 16, 6:08 AM CDT | River Flood Warning | FSD | 8 days |
| Mar 19, 7:40 AM CDT | River Flood Warning | FSD | 8 days |
| Mar 30, 3:05 PM CDT | Wind Advisory | FSD | 22 hr |
| Apr 2, 2:20 PM CDT | Winter Weather Advisory | FSD | 31 hr |
| Apr 11, 3:37 PM CDT | Winter Storm Watch | FSD | 24 hr |
| Apr 12, 3:45 PM CDT | Blizzard Warning | FSD | 60 hr |
| Apr 13, 11:36 AM CDT | Severe Thunderstorm Warning | FSD | 39 min |
| Apr 17, 3:33 AM CDT | Winter Weather Advisory | FSD | 38 hr |
| Apr 18, 10:02 AM CDT | River Flood Warning | FSD | 15 days |
| Apr 18, 10:02 AM CDT | River Flood Warning | FSD | 6 days |
| Apr 29, 3:41 AM CDT | Wind Advisory | FSD | 16 hr |
| Apr 30, 5:40 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Apr 30, 8:13 PM CDT | Mesoscale Discussion | SPC | 92 min |
| May 23, 2:00 PM CDT | Severe Thunderstorm Warning | FSD | 30 min |
| May 23, 2:36 PM CDT | Mesoscale Discussion | SPC | 114 min |
| May 24, 2:36 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 1, 6:32 PM CDT | Mesoscale Discussion | SPC | 88 min |
| Jun 1, 7:24 PM CDT | Severe Thunderstorm Warning | FSD | 36 min |
| Jun 1, 9:02 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Jun 8, 5:55 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 8, 8:40 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Jun 8, 11:51 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Jun 27, 4:18 AM CDT | Mesoscale Discussion | SPC | 87 min |
| Jun 27, 4:34 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 27, 6:25 AM CDT | Severe Thunderstorm Warning | FSD | 35 min |
| Jun 27, 6:55 AM CDT | Severe Thunderstorm Warning | FSD | 35 min |
| Jun 27, 7:25 AM CDT | Mesoscale Discussion | SPC | 95 min |
| Jul 3, 3:43 AM CDT | Heat Advisory | FSD | 16 hr |
| Jul 7, 3:01 PM CDT | Heat Advisory | FSD | 29 hr |
| Jul 10, 2:39 PM CDT | Heat Advisory | FSD | 53 hr |
| Jul 12, 4:47 AM CDT | Flash Flood Watch | FSD | 26 hr |
| Jul 12, 3:24 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 12, 6:36 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Jul 12, 7:23 PM CDT | Flash Flood Warning | FSD | 3 hr |
| Jul 12, 9:46 PM CDT | Flash Flood Warning | FSD | 6 hr |
| Jul 18, 1:39 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 18, 3:43 PM CDT | Tornado Watch | SPC | 7 hr |
| Jul 18, 5:16 PM CDT | Mesoscale Discussion | SPC | 119 min |
| Aug 3, 4:05 PM CDT | Mesoscale Discussion | SPC | 55 min |
| Aug 4, 11:39 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 5, 12:34 AM CDT | Severe Thunderstorm Warning | FSD | 41 min |
| Aug 5, 1:00 AM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Aug 5, 1:08 AM CDT | Severe Thunderstorm Warning | FSD | 52 min |
| Aug 27, 6:17 PM CDT | Mesoscale Discussion | SPC | 88 min |
| Aug 27, 6:42 PM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Aug 27, 9:07 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Aug 27, 9:08 PM CDT | Mesoscale Discussion | SPC | 97 min |
| Aug 28, 12:42 AM CDT | Severe Thunderstorm Warning | FSD | 33 min |
| Aug 28, 1:07 AM CDT | Severe Thunderstorm Warning | FSD | 38 min |
| Sep 18, 2:48 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 19, 2:40 AM CDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 19, 10:31 AM CDT | Flash Flood Watch | FSD | 26 hr |
| Oct 3, 10:18 AM CDT | Wind Advisory | FSD | 11 hr |
| Oct 3, 3:30 PM CDT | Frost Advisory | FSD | 18 hr |
| Oct 3, 3:30 PM CDT | Freeze Warning | FSD | 18 hr |
| Oct 5, 1:41 PM CDT | Frost Advisory | FSD | 19 hr |
| Oct 10, 3:18 PM CDT | Freeze Warning | FSD | 18 hr |
| Oct 11, 3:35 AM CDT | Freeze Warning | FSD | 29 hr |
| Nov 16, 3:26 AM CST | Winter Weather Advisory | FSD | 25 hr |
| Nov 22, 4:24 AM CST | Dense Fog Advisory | FSD | 7 hr |
| Nov 28, 4:05 AM CST | Winter Weather Advisory | FSD | 17 hr |
| Nov 28, 2:25 PM CST | Winter Storm Watch | FSD | 48 hr |
| Nov 29, 2:45 PM CST | Winter Storm Warning | FSD | 69 hr |
| Nov 29, 9:09 PM CST | Dense Fog Advisory | FSD | 15 hr |
| Dec 8, 2:00 AM CST | Dense Fog Advisory | FSD | 10 hr |
| Dec 25, 3:17 AM CST | Winter Storm Watch | FSD | 24 hr |
| Dec 25, 3:17 PM CST | Winter Storm Warning | FSD | 69 hr |
| Dec 26, 3:25 AM CST | Winter Weather Advisory | FSD | 57 hr |
| Dec 28, 2:32 PM CST | Wind Chill Advisory | FSD | 18 hr |
| Dec 30, 3:33 PM CST | Winter Weather Advisory | FSD | 29 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 | 9 |
| Severe Thunderstorm Watch | 6 |
| Tornado Watch | 1 |
| Mesoscale Discussion | 20 |
| Flooding | |
| Flash Flood Warning | 2 |
| River Flood Warning | 4 |
| Flash Flood Watch | 2 |
| Winter | |
| Blizzard Warning | 2 |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 6 |
| Winter Weather Advisory | 13 |
| Heat | |
| Heat Advisory | 3 |
| Cold | |
| Freeze Warning | 3 |
| Frost Advisory | 2 |
| Wind Chill Advisory | 6 |
| Wind and dust | |
| Wind Advisory | 3 |
| Fog and smoke | |
| Dense Fog Advisory | 4 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20172019
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.