Alert archive / South Dakota / Douglas County
Weather alerts in Douglas County, South Dakota, 2015
99 weather alerts in 2015, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Douglas County and its neighbors
Each county as a circle sized by its count in 2015. Tap one for its archive.
- Alerts
- 99
- Warnings
- 23
- Watches
- 18
- Advisories
- 33
- Busiest month
- June21 alerts
- Busiest day
- May 10, 20156 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
2 of 2 tornado warnings covering Douglas County in 2015 had a tornado report inside them; 1 of 1 tornado reports fell inside a warning, on average 15 minutes after it went out.
Douglas County, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 2 | 2 | 0% | 1 | 100% | 15 min |
| Severe thunderstorm warnings | 13 | 8 | 38% | 4 | 100% | 16 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Sioux Falls, SD: tornado warnings | 30 | 13 | 57% | 25 | 68% | 14 min |
| NWS Sioux Falls, SD: severe thunderstorm warnings | 175 | 123 | 30% | 220 | 86% | 20 min |
| NWS Sioux Falls, SD: flash flood warnings | 19 | 13 | 32% | 19 | 95% | 37 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 2, 3:25 PM CST | Wind Chill Advisory | FSD | 69 hr |
| Jan 3, 9:34 AM CST | Wind Advisory | FSD | 11 hr |
| Jan 5, 4:19 AM CST | Winter Weather Advisory | FSD | 15 hr |
| Jan 5, 5:16 PM CST | Wind Chill Advisory | FSD | 19 hr |
| Jan 6, 4:25 AM CST | Wind Chill Advisory | FSD | 47 hr |
| Jan 7, 4:36 AM CST | Blizzard Watch | FSD | 23 hr |
| Jan 7, 3:26 PM CST | Winter Weather Advisory | FSD | 37 hr |
| Jan 8, 3:54 AM CST | Wind Chill Advisory | FSD | 30 hr |
| Jan 16, 2:58 PM CST | Wind Advisory | FSD | 25 hr |
| Jan 28, 12:36 PM CST | Wind Advisory | FSD | 20 hr |
| Jan 31, 3:50 AM CST | Winter Weather Advisory | FSD | 35 hr |
| Feb 9, 12:58 AM CST | Dense Fog Advisory | FSD | 12 hr |
| Feb 9, 7:41 PM CST | Dense Fog Advisory | FSD | 7 hr |
| Feb 17, 2:54 AM CST | Wind Chill Advisory | FSD | 33 hr |
| Mar 1, 9:59 PM CST | Blizzard Watch | FSD | 17 hr |
| Mar 2, 2:39 PM CST | Winter Weather Advisory | FSD | 26 hr |
| Mar 28, 3:06 PM CDT | Wind Advisory | FSD | 28 hr |
| Apr 14, 11:45 AM CDT | Wind Advisory | FSD | 22 hr |
| Apr 20, 3:31 AM CDT | Wind Advisory | FSD | 15 hr |
| Apr 21, 3:53 AM CDT | Freeze Warning | FSD | 28 hr |
| Apr 24, 5:36 PM CDT | Severe Thunderstorm Warning | FSD | 39 min |
| Apr 24, 6:10 PM CDT | Severe Thunderstorm Warning | FSD | 50 min |
| Apr 24, 6:37 PM CDT | Areal Flood Warning | FSD | 12 hr |
| May 10, 9:54 AM CDT | Severe Thunderstorm Warning | FSD | 36 min |
| May 10, 10:16 AM CDT | Severe Thunderstorm Warning | FSD | 29 min |
| May 10, 10:24 AM CDT | Mesoscale Discussion | SPC | 3 hr |
| May 10, 10:29 AM CDT | Tornado Warning | FSD | 31 min |
| May 10, 10:46 AM CDT | Tornado Watch | SPC | 8 hr |
| May 10, 10:55 AM CDT | Tornado Warning | FSD | 35 min |
| May 11, 2:54 PM CDT | Frost Advisory | FSD | 17 hr |
| May 16, 2:10 PM CDT | Mesoscale Discussion | SPC | 95 min |
| May 17, 11:44 AM CDT | Wind Advisory | FSD | 16 hr |
| May 17, 3:20 PM CDT | Freeze Warning | FSD | 41 hr |
| Jun 2, 9:01 PM CDT | Mesoscale Discussion | SPC | 89 min |
| Jun 2, 11:57 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 3, 3:01 AM CDT | Mesoscale Discussion | SPC | 89 min |
| Jun 6, 2:32 PM CDT | Mesoscale Discussion | SPC | 88 min |
| Jun 6, 3:40 PM CDT | Tornado Watch | SPC | 5 hr |
| Jun 6, 6:34 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jun 6, 8:11 PM CDT | Mesoscale Discussion | SPC | 64 min |
| Jun 9, 4:49 PM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Jun 10, 2:42 PM CDT | Flash Flood Watch | FSD | 19 hr |
| Jun 19, 10:01 AM CDT | Mesoscale Discussion | SPC | 89 min |
| Jun 19, 10:31 PM CDT | Mesoscale Discussion | SPC | 59 min |
| Jun 19, 10:57 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 20, 1:02 AM CDT | Mesoscale Discussion | SPC | 58 min |
| Jun 20, 1:21 AM CDT | Severe Thunderstorm Warning | FSD | 39 min |
| Jun 20, 1:48 AM CDT | Severe Thunderstorm Warning | FSD | 27 min |
| Jun 20, 2:17 AM CDT | Severe Thunderstorm Warning | FSD | 43 min |
| Jun 22, 2:25 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 22, 3:16 AM CDT | Mesoscale Discussion | SPC | 89 min |
| Jun 22, 4:53 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 22, 5:34 AM CDT | High Wind Warning | FSD | 2 hr |
| Jun 27, 9:39 PM CDT | Severe Thunderstorm Warning | FSD | 23 min |
| Jul 3, 6:19 AM CDT | Dense Fog Advisory | FSD | 3 hr |
| Jul 5, 3:46 PM CDT | Mesoscale Discussion | SPC | 119 min |
| Jul 5, 4:51 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 5, 8:45 PM CDT | Mesoscale Discussion | SPC | 90 min |
| Jul 5, 9:02 PM CDT | Flash Flood Watch | FSD | 8 hr |
| Jul 5, 9:57 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 11, 4:00 AM CDT | Heat Advisory | FSD | 39 hr |
| Jul 23, 3:04 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 25, 10:52 AM CDT | Severe Thunderstorm Warning | FSD | 38 min |
| Jul 25, 6:13 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 25, 9:32 PM CDT | Severe Thunderstorm Watch | SPC | 3 hr |
| Jul 25, 10:13 PM CDT | Severe Thunderstorm Warning | FSD | 32 min |
| Jul 25, 10:43 PM CDT | Severe Thunderstorm Warning | FSD | 47 min |
| Jul 25, 10:54 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 27, 9:41 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 27, 10:49 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 28, 1:50 AM CDT | Severe Thunderstorm Warning | FSD | 18 min |
| Jul 28, 1:57 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 6, 1:51 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Aug 6, 3:23 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 9, 1:05 PM CDT | Mesoscale Discussion | SPC | 115 min |
| Aug 9, 1:42 PM CDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Aug 9, 4:03 PM CDT | Mesoscale Discussion | SPC | 117 min |
| Aug 9, 5:28 PM CDT | Severe Thunderstorm Warning | FSD | 47 min |
| Aug 14, 7:24 PM CDT | Heat Advisory | FSD | 24 hr |
| Aug 21, 3:11 PM CDT | Wind Advisory | FSD | 39 hr |
| Sep 22, 10:23 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 23, 4:14 AM CDT | Flash Flood Watch | FSD | 27 hr |
| Oct 11, 4:20 PM CDT | Wind Advisory | FSD | 26 hr |
| Oct 15, 3:34 AM CDT | Freeze Warning | FSD | 29 hr |
| Oct 28, 3:33 AM CDT | Wind Advisory | FSD | 15 hr |
| Nov 10, 3:02 PM CST | Wind Advisory | FSD | 51 hr |
| Nov 18, 3:52 AM CST | Wind Advisory | FSD | 38 hr |
| Nov 19, 3:44 PM CST | Winter Storm Warning | FSD | 30 hr |
| Nov 19, 3:44 PM CST | Winter Weather Advisory | FSD | 29 hr |
| Nov 28, 2:41 PM CST | Winter Storm Watch | FSD | 25 hr |
| Nov 29, 3:26 PM CST | Winter Storm Warning | FSD | 42 hr |
| Nov 29, 3:26 PM CST | Winter Weather Advisory | FSD | 21 hr |
| Dec 1, 3:46 AM CST | Winter Weather Advisory | FSD | 11 hr |
| Dec 14, 2:23 PM CST | Winter Weather Advisory | FSD | 49 hr |
| Dec 23, 3:04 PM CST | Winter Storm Watch | FSD | 25 hr |
| Dec 24, 3:47 PM CST | Winter Storm Warning | FSD | 50 hr |
| Dec 24, 3:47 PM CST | Winter Weather Advisory | FSD | 47 hr |
| Dec 25, 5:35 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Dec 28, 3:39 AM CST | Winter Weather Advisory | FSD | 31 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 | 13 |
| Tornado Warning | 2 |
| Severe Thunderstorm Watch | 9 |
| Tornado Watch | 2 |
| Mesoscale Discussion | 25 |
| Flooding | |
| Areal Flood Warning | 1 |
| Flash Flood Watch | 3 |
| Winter | |
| Winter Storm Warning | 3 |
| Blizzard Watch | 2 |
| Winter Storm Watch | 2 |
| Winter Weather Advisory | 10 |
| Heat | |
| Heat Advisory | 2 |
| Cold | |
| Freeze Warning | 3 |
| Frost Advisory | 1 |
| Wind Chill Advisory | 5 |
| Wind and dust | |
| High Wind Warning | 1 |
| Wind Advisory | 12 |
| 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 archive20142016
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.