Alert archive / South Dakota / Gregory County
Weather alerts in Gregory County, South Dakota, 2013
87 weather alerts in 2013, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Gregory County and its neighbors
Each county as a circle sized by its count in 2013. Tap one for its archive.
- Alerts
- 87
- Warnings
- 13
- Watches
- 16
- Advisories
- 35
- Busiest month
- June15 alerts
- Busiest day
- June 22, 20137 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Gregory County, 2013
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 10 | 7 | 30% | 2 | 100% | 9 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2013
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Sioux Falls, SD: tornado warnings | 20 | 12 | 40% | 38 | 84% | 21 min |
| NWS Sioux Falls, SD: severe thunderstorm warnings | 123 | 86 | 30% | 169 | 87% | 21 min |
| NWS Sioux Falls, SD: flash flood warnings | 16 | 11 | 31% | 17 | 82% | 89 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 8, 3:33 AM CST | Wind Advisory | FSD | 11 hr |
| Jan 11, 3:34 AM CST | Winter Weather Advisory | FSD | 29 hr |
| Jan 28, 4:04 AM CST | Winter Weather Advisory | FSD | 26 hr |
| Jan 30, 4:09 AM CST | Wind Chill Advisory | FSD | 53 hr |
| Feb 7, 2:52 PM CST | Winter Storm Watch | FSD | 13 hr |
| Feb 8, 4:11 AM CST | Blizzard Watch | FSD | 36 hr |
| Feb 9, 4:25 AM CST | Blizzard Warning | FSD | 56 hr |
| Feb 10, 1:38 AM CST | Mesoscale Discussion | SPC | 5 hr |
| Feb 17, 3:11 PM CST | Wind Advisory | FSD | 30 hr |
| Feb 19, 3:36 AM CST | Winter Storm Watch | FSD | 35 hr |
| Feb 20, 11:02 AM CST | Winter Weather Advisory | FSD | 49 hr |
| Mar 3, 2:33 PM CST | Wind Advisory | FSD | 48 hr |
| Mar 8, 3:06 PM CST | Winter Weather Advisory | FSD | 30 hr |
| Mar 17, 4:27 AM CDT | Wind Advisory | FSD | 39 hr |
| Mar 17, 4:27 AM CDT | Wind Advisory | FSD | 15 hr |
| Apr 7, 3:55 AM CDT | Winter Storm Watch | FSD | 25 hr |
| Apr 8, 4:59 AM CDT | Winter Storm Warning | FSD | 3 days |
| Apr 8, 5:41 AM CDT | Dense Fog Advisory | FSD | 4 hr |
| Apr 9, 6:46 PM CDT | Mesoscale Discussion | SPC | 5 hr |
| Apr 14, 3:38 AM CDT | Wind Advisory | FSD | 11 hr |
| Apr 15, 4:22 AM CDT | Winter Storm Watch | FSD | 35 hr |
| Apr 16, 3:30 PM CDT | Winter Weather Advisory | FSD | 48 hr |
| Apr 17, 3:42 PM CDT | Winter Weather Advisory | FSD | 24 hr |
| Apr 21, 4:05 PM CDT | Winter Weather Advisory | FSD | 30 hr |
| May 6, 5:31 AM CDT | Dense Fog Advisory | FSD | 3 hr |
| May 17, 7:28 PM CDT | Mesoscale Discussion | SPC | 92 min |
| May 17, 7:59 PM CDT | Severe Thunderstorm Watch | SPC | 3 hr |
| May 17, 10:26 PM CDT | Mesoscale Discussion | SPC | 64 min |
| May 18, 8:33 PM CDT | Mesoscale Discussion | SPC | 117 min |
| May 18, 9:26 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| May 24, 10:27 AM CDT | Wind Advisory | FSD | 6 hr |
| May 28, 7:52 PM CDT | Mesoscale Discussion | SPC | 113 min |
| May 31, 3:55 AM CDT | Wind Advisory | FSD | 21 hr |
| Jun 3, 10:16 PM CDT | Severe Thunderstorm Warning | FSD | 29 min |
| Jun 21, 9:09 AM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 21, 1:58 PM CDT | Tornado Watch | SPC | 7 hr |
| Jun 21, 5:59 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Jun 21, 8:56 PM CDT | Mesoscale Discussion | SPC | 94 min |
| Jun 21, 9:07 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 21, 10:49 PM CDT | Severe Thunderstorm Warning | FSD | 41 min |
| Jun 21, 11:03 PM CDT | Severe Thunderstorm Warning | FSD | 42 min |
| Jun 21, 11:19 PM CDT | Severe Thunderstorm Warning | FSD | 41 min |
| Jun 21, 11:26 PM CDT | Severe Thunderstorm Warning | FSD | 49 min |
| Jun 22, 4:18 AM CDT | Flash Flood Watch | FSD | 27 hr |
| Jun 22, 9:21 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 22, 10:34 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Jun 22, 10:57 PM CDT | Severe Thunderstorm Warning | FSD | 63 min |
| Jun 22, 11:48 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Jul 7, 5:03 PM CDT | Severe Thunderstorm Warning | FSD | 42 min |
| Jul 7, 5:35 PM CDT | Mesoscale Discussion | SPC | 115 min |
| Jul 7, 5:43 PM CDT | Severe Thunderstorm Warning | FSD | 62 min |
| Jul 7, 6:03 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 7, 6:23 PM CDT | Severe Thunderstorm Warning | FSD | 67 min |
| Jul 8, 2:51 PM CDT | Mesoscale Discussion | SPC | 54 min |
| Jul 8, 4:00 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 8, 7:36 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Jul 8, 10:03 PM CDT | Mesoscale Discussion | SPC | 57 min |
| Jul 12, 3:35 AM CDT | Heat Advisory | FSD | 17 hr |
| Jul 17, 2:55 PM CDT | Heat Advisory | FSD | 28 hr |
| Jul 20, 8:23 PM CDT | Mesoscale Discussion | SPC | 97 min |
| Jul 24, 1:18 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Aug 1, 8:16 AM CDT | Mesoscale Discussion | SPC | 59 min |
| Aug 1, 1:22 PM CDT | Tornado Watch | SPC | 9 hr |
| Aug 1, 3:25 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Aug 2, 8:41 AM CDT | Severe Thunderstorm Warning | FSD | 49 min |
| Aug 5, 6:14 AM CDT | Mesoscale Discussion | SPC | 91 min |
| Aug 6, 2:42 AM CDT | Mesoscale Discussion | SPC | 93 min |
| Aug 6, 2:48 AM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Aug 6, 5:07 AM CDT | Mesoscale Discussion | SPC | 83 min |
| Aug 12, 2:26 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 24, 3:13 AM CDT | Heat Advisory | FSD | 7 days |
| Aug 31, 3:01 PM CDT | Mesoscale Discussion | SPC | 119 min |
| Sep 6, 3:31 AM CDT | Heat Advisory | FSD | 15 hr |
| Sep 30, 10:33 PM CDT | Wind Advisory | FSD | 4 hr |
| Oct 5, 9:18 AM CDT | Wind Advisory | FSD | 12 hr |
| Oct 10, 4:21 AM CDT | Wind Advisory | FSD | 41 hr |
| Oct 14, 3:04 PM CDT | Wind Advisory | FSD | 22 hr |
| Oct 31, 3:15 PM CDT | Wind Advisory | FSD | 28 hr |
| Nov 4, 3:31 PM CST | Winter Weather Advisory | FSD | 36 hr |
| Dec 3, 3:42 AM CST | Winter Weather Advisory | FSD | 41 hr |
| Dec 3, 3:09 PM CST | Winter Storm Warning | FSD | 30 hr |
| Dec 4, 3:17 PM CST | Wind Chill Advisory | FSD | 69 hr |
| Dec 8, 3:54 AM CST | Wind Chill Advisory | FSD | 32 hr |
| Dec 10, 12:32 AM CST | Wind Advisory | FSD | 5 hr |
| Dec 22, 3:54 AM CST | Wind Chill Advisory | FSD | 56 hr |
| Dec 27, 3:14 PM CST | Wind Chill Advisory | FSD | 60 hr |
| Dec 28, 4:04 AM CST | Wind Advisory | FSD | 24 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 | 10 |
| Severe Thunderstorm Watch | 8 |
| Tornado Watch | 2 |
| Mesoscale Discussion | 23 |
| Flooding | |
| Flash Flood Watch | 1 |
| Winter | |
| Blizzard Warning | 1 |
| Winter Storm Warning | 2 |
| Blizzard Watch | 1 |
| Winter Storm Watch | 4 |
| Winter Weather Advisory | 9 |
| Heat | |
| Heat Advisory | 4 |
| Cold | |
| Wind Chill Advisory | 5 |
| Wind and dust | |
| Wind Advisory | 15 |
| Fog and smoke | |
| Dense Fog Advisory | 2 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20122014
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.