Alert archive / South Dakota / Mellette County
Weather alerts in Mellette County, South Dakota, 2017
99 weather alerts in 2017, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Mellette County and its neighbors
Each county as a circle sized by its count in 2017. Tap one for its archive.
- Alerts
- 99
- Warnings
- 23
- Watches
- 12
- Advisories
- 23
- Busiest month
- August31 alerts
- Busiest day
- June 13, 20176 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Mellette County, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 18 | 14 | 22% | 4 | 100% | 12 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Rapid City, SD: tornado warnings | 4 | 1 | 75% | 3 | 33% | 21 min |
| NWS Rapid City, SD: severe thunderstorm warnings | 183 | 121 | 34% | 257 | 88% | 27 min |
| NWS Rapid City, SD: flash flood warnings | 4 | 1 | 75% | 1 | 100% | 142 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 3, 10:58 AM CST | Wind Chill Advisory | UNR | 71 hr |
| Jan 22, 2:56 PM CST | Winter Storm Watch | UNR | 24 hr |
| Jan 23, 2:38 PM CST | Winter Storm Warning | UNR | 39 hr |
| Jan 27, 10:32 AM CST | Winter Weather Advisory | UNR | 13 hr |
| Jan 30, 3:22 AM CST | Wind Advisory | UNR | 13 hr |
| Feb 7, 2:48 PM CST | Winter Weather Advisory | UNR | 15 hr |
| Feb 19, 9:22 PM CST | Areal Flood Advisory | UNR | 48 hr |
| Feb 21, 3:46 PM CST | Winter Storm Watch | UNR | 24 hr |
| Feb 22, 3:34 PM CST | Winter Storm Warning | UNR | 37 hr |
| Mar 5, 4:06 AM CST | High Wind Watch | UNR | 231 days |
| Mar 5, 4:14 PM CST | High Wind Warning | UNR | 27 hr |
| Mar 6, 4:02 AM CST | High Wind Watch | UNR | 233 days |
| Mar 7, 4:16 AM CST | Wind Advisory | UNR | 16 hr |
| Apr 13, 5:20 AM CDT | Dense Fog Advisory | UNR | 5 hr |
| May 20, 3:29 PM CDT | Frost Advisory | UNR | 12 hr |
| May 23, 2:51 PM CDT | Frost Advisory | UNR | 17 hr |
| May 28, 3:54 PM CDT | Mesoscale Discussion | SPC | 66 min |
| May 28, 5:17 PM CDT | Special Weather Statement | UNR | 58 min |
| Jun 2, 2:48 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Jun 2, 7:16 PM CDT | Special Weather Statement | UNR | 29 min |
| Jun 10, 9:44 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 10, 10:01 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 10, 11:56 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 12, 6:35 PM CDT | Tornado Watch | SPC | 8 hr |
| Jun 12, 9:02 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Jun 12, 10:59 PM CDT | Severe Thunderstorm Warning | UNR | 76 min |
| Jun 12, 11:14 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Jun 13, 12:14 AM CDT | Severe Thunderstorm Warning | UNR | 50 min |
| Jun 13, 12:53 AM CDT | Severe Thunderstorm Warning | UNR | 24 min |
| Jun 13, 2:32 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Jun 27, 5:07 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 27, 7:21 PM CDT | Severe Thunderstorm Warning | UNR | 54 min |
| Jun 27, 8:12 PM CDT | Mesoscale Discussion | SPC | 93 min |
| Jul 5, 9:36 PM CDT | Severe Thunderstorm Warning | UNR | 69 min |
| Jul 7, 9:13 PM CDT | Severe Thunderstorm Warning | UNR | 47 min |
| Jul 7, 10:03 PM CDT | Special Weather Statement | UNR | 42 min |
| Jul 9, 5:17 PM CDT | Special Weather Statement | UNR | 28 min |
| Jul 17, 7:21 PM CDT | Special Weather Statement | UNR | 24 min |
| Jul 18, 3:24 PM CDT | Heat Advisory | UNR | 28 hr |
| Jul 19, 2:52 PM CDT | Mesoscale Discussion | SPC | 83 min |
| Jul 20, 3:00 PM CDT | Heat Advisory | UNR | 29 hr |
| Jul 24, 3:55 AM CDT | Heat Advisory | UNR | 16 hr |
| Jul 24, 3:49 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Jul 24, 5:52 PM CDT | Special Weather Statement | UNR | 23 min |
| Jul 25, 2:41 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 25, 3:22 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 25, 6:19 PM CDT | Severe Thunderstorm Warning | UNR | 56 min |
| Jul 25, 6:25 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Jul 25, 7:03 PM CDT | Severe Thunderstorm Warning | UNR | 57 min |
| Jul 28, 6:09 PM CDT | Special Weather Statement | UNR | 51 min |
| Jul 28, 6:46 PM CDT | Special Weather Statement | UNR | 59 min |
| Jul 30, 2:17 PM CDT | Severe Thunderstorm Warning | UNR | 58 min |
| Aug 1, 12:36 PM CDT | Severe Thunderstorm Warning | UNR | 37 min |
| Aug 2, 2:15 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 6, 4:09 PM CDT | Special Weather Statement | UNR | 51 min |
| Aug 6, 4:45 PM CDT | Severe Thunderstorm Warning | UNR | 60 min |
| Aug 12, 2:16 PM CDT | Severe Thunderstorm Warning | UNR | 59 min |
| Aug 12, 2:36 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Aug 12, 3:08 PM CDT | Severe Thunderstorm Warning | UNR | 67 min |
| Aug 12, 3:59 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 12, 6:16 PM CDT | Mesoscale Discussion | SPC | 89 min |
| Aug 12, 6:31 PM CDT | Areal Flood Advisory | UNR | 3 hr |
| Aug 15, 3:52 PM CDT | Mesoscale Discussion | SPC | 113 min |
| Aug 15, 6:11 PM CDT | Special Weather Statement | UNR | 34 min |
| Aug 15, 6:29 PM CDT | Special Weather Statement | UNR | 31 min |
| Aug 15, 7:20 PM CDT | Special Weather Statement | UNR | 25 min |
| Aug 15, 7:53 PM CDT | Special Weather Statement | UNR | 37 min |
| Aug 15, 8:06 PM CDT | Severe Thunderstorm Warning | UNR | 54 min |
| Aug 17, 4:42 PM CDT | Special Weather Statement | UNR | 33 min |
| Aug 17, 5:19 PM CDT | Special Weather Statement | UNR | 26 min |
| Aug 17, 6:00 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 21, 8:55 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 21, 9:42 AM CDT | Severe Thunderstorm Warning | UNR | 63 min |
| Aug 21, 10:51 AM CDT | Special Weather Statement | UNR | 54 min |
| Aug 26, 2:13 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 26, 3:04 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 26, 4:24 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 26, 5:45 PM CDT | Severe Thunderstorm Warning | UNR | 60 min |
| Aug 26, 6:37 PM CDT | Severe Thunderstorm Warning | UNR | 53 min |
| Aug 26, 7:40 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 26, 9:28 PM CDT | Special Weather Statement | UNR | 47 min |
| Aug 26, 11:12 PM CDT | Special Weather Statement | UNR | 48 min |
| Aug 26, 11:21 PM CDT | Severe Thunderstorm Warning | UNR | 54 min |
| Sep 8, 7:56 PM CDT | Mesoscale Discussion | SPC | 94 min |
| Sep 12, 7:34 PM CDT | Special Weather Statement | UNR | 56 min |
| Sep 19, 1:51 PM CDT | Mesoscale Discussion | SPC | 54 min |
| Oct 3, 4:08 AM CDT | Freeze Watch | UNR | 11 hr |
| Oct 3, 4:08 AM CDT | Freeze Warning | UNR | 29 hr |
| Oct 22, 3:46 PM CDT | Wind Advisory | UNR | 27 hr |
| Oct 25, 3:10 PM CDT | Wind Advisory | UNR | 29 hr |
| Nov 28, 1:24 PM CST | Wind Advisory | UNR | 30 hr |
| Dec 3, 4:10 AM CST | Winter Weather Advisory | UNR | 38 hr |
| Dec 5, 4:34 AM CST | Wind Advisory | UNR | 14 hr |
| Dec 10, 3:54 PM CST | Wind Advisory | UNR | 25 hr |
| Dec 12, 2:44 PM CST | Wind Advisory | UNR | 23 hr |
| Dec 25, 4:17 AM CST | Wind Chill Advisory | UNR | 32 hr |
| Dec 26, 3:45 PM CST | Wind Chill Advisory | UNR | 18 hr |
| Dec 29, 4:47 AM CST | Wind Chill Advisory | UNR | 3 days |
| Dec 30, 3:58 AM CST | Wind Chill Warning | UNR | 56 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 | 18 |
| Severe Thunderstorm Watch | 6 |
| Tornado Watch | 1 |
| Mesoscale Discussion | 22 |
| Special Weather Statement | 19 |
| Flooding | |
| Areal Flood Advisory | 2 |
| Winter | |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 2 |
| Winter Weather Advisory | 3 |
| Heat | |
| Heat Advisory | 3 |
| Cold | |
| Freeze Warning | 1 |
| Wind Chill Warning | 1 |
| Freeze Watch | 1 |
| Frost Advisory | 2 |
| Wind Chill Advisory | 4 |
| Wind and dust | |
| High Wind Warning | 1 |
| High Wind Watch | 2 |
| Wind Advisory | 8 |
| Fog and smoke | |
| Dense Fog Advisory | 1 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20162018
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.