Alert archive / South Dakota / Gregory County
Weather alerts in Gregory County, South Dakota, 2008
145 weather alerts in 2008, 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 2008. Tap one for its archive.
- Alerts
- 145
- Warnings
- 48
- Watches
- 27
- Advisories
- 32
- Busiest month
- June42 alerts
- Busiest day
- June 17, 200810 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
0 of 2 tornado warnings covering Gregory County in 2008 had a tornado report inside them.
Gregory County, 2008
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 2 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 32 | 14 | 56% | 15 | 87% | 22 min |
| Flash flood warnings | 3 | 1 | 67% | 2 | 100% | 86 min |
Each office's whole area, 2008
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Sioux Falls, SD: tornado warnings | 55 | 19 | 65% | 49 | 90% | 14 min |
| NWS Sioux Falls, SD: severe thunderstorm warnings | 296 | 130 | 56% | 253 | 82% | 19 min |
| NWS Sioux Falls, SD: flash flood warnings | 28 | 20 | 29% | 44 | 89% | 88 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 19, 3:16 PM CST | Snow Advisory | FSD | 51 hr |
| Jan 21, 9:10 PM CST | Wind Chill Advisory | FSD | 14 hr |
| Jan 22, 3:55 PM CST | Blowing Snow Advisory | FSD | 19 hr |
| Jan 28, 3:16 PM CST | Winter Weather Advisory | FSD | 21 hr |
| Jan 28, 7:22 PM CST | Wind Advisory | FSD | 11 hr |
| Jan 29, 4:19 AM CST | Wind Chill Advisory | FSD | 29 hr |
| Feb 10, 9:43 PM CST | Snow Advisory | FSD | 29 hr |
| Feb 17, 12:25 PM CST | Wind Advisory | FSD | 7 hr |
| Feb 19, 4:00 AM CST | Wind Chill Advisory | FSD | 31 hr |
| Mar 2, 3:34 AM CST | Wind Advisory | FSD | 14 hr |
| Mar 15, 2:41 PM CDT | Snow Advisory | FSD | 25 hr |
| Mar 16, 3:58 PM CDT | Winter Storm Watch | FSD | 23 hr |
| Mar 29, 3:55 AM CDT | Wind Advisory | FSD | 15 hr |
| Mar 30, 4:38 AM CDT | Winter Storm Watch | FSD | 10 hr |
| Mar 30, 2:32 PM CDT | Heavy Snow Warning | FSD | 28 hr |
| Mar 31, 2:30 AM CDT | Mesoscale Discussion | SPC | 5 hr |
| Apr 9, 3:47 AM CDT | Winter Storm Watch | FSD | 24 hr |
| Apr 9, 8:00 PM CDT | Winter Storm Warning | FSD | 8 hr |
| Apr 10, 4:10 AM CDT | Blizzard Warning | FSD | 32 hr |
| Apr 10, 4:10 AM CDT | Winter Weather Advisory | FSD | 32 hr |
| Apr 10, 2:14 PM CDT | Mesoscale Discussion | SPC | 4 hr |
| Apr 14, 3:53 PM CDT | Wind Advisory | FSD | 29 hr |
| Apr 20, 3:16 AM CDT | Wind Advisory | FSD | 16 hr |
| Apr 25, 6:06 AM CDT | Mesoscale Discussion | SPC | 6 hr |
| Apr 25, 8:12 AM CDT | Winter Weather Advisory | FSD | 17 hr |
| May 2, 3:49 PM CDT | Wind Advisory | FSD | 12 hr |
| May 6, 10:56 AM CDT | Mesoscale Discussion | SPC | 94 min |
| May 6, 11:59 AM CDT | Severe Thunderstorm Warning | FSD | 45 min |
| May 6, 12:03 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 6, 1:09 PM CDT | Severe Thunderstorm Warning | FSD | 51 min |
| May 10, 3:22 AM CDT | Wind Advisory | FSD | 25 hr |
| May 17, 12:16 PM CDT | Wind Advisory | FSD | 8 hr |
| May 19, 12:48 PM CDT | Wind Advisory | FSD | 7 hr |
| May 23, 6:56 PM CDT | High Wind Warning | FSD | 3 hr |
| May 24, 1:18 PM CDT | Mesoscale Discussion | SPC | 57 min |
| May 24, 2:17 PM CDT | Mesoscale Discussion | SPC | 118 min |
| May 24, 2:39 PM CDT | Tornado Watch | SPC | 7 hr |
| May 24, 6:07 PM CDT | Mesoscale Discussion | SPC | 113 min |
| May 28, 11:41 PM CDT | Mesoscale Discussion | SPC | 94 min |
| Jun 2, 7:11 PM CDT | Mesoscale Discussion | SPC | 34 min |
| Jun 2, 10:02 PM CDT | Mesoscale Discussion | SPC | 118 min |
| Jun 2, 11:36 PM CDT | Severe Thunderstorm Warning | FSD | 39 min |
| Jun 2, 11:58 PM CDT | Severe Thunderstorm Warning | FSD | 47 min |
| Jun 3, 12:35 AM CDT | Severe Thunderstorm Warning | FSD | 40 min |
| Jun 3, 1:05 AM CDT | Severe Thunderstorm Warning | FSD | 40 min |
| Jun 4, 3:00 PM CDT | Flash Flood Watch | FSD | 12 hr |
| Jun 5, 10:11 AM CDT | Mesoscale Discussion | SPC | 94 min |
| Jun 5, 10:35 AM CDT | Flash Flood Watch | FSD | 11 hr |
| Jun 5, 10:38 AM CDT | Severe Thunderstorm Warning | FSD | 37 min |
| Jun 5, 12:04 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 5, 2:01 PM CDT | Mesoscale Discussion | SPC | 59 min |
| Jun 5, 3:40 PM CDT | Flash Flood Warning | FSD | 4 hr |
| Jun 5, 3:57 PM CDT | Severe Thunderstorm Warning | FSD | 48 min |
| Jun 5, 4:42 PM CDT | Severe Thunderstorm Warning | FSD | 48 min |
| Jun 11, 12:39 AM CDT | Mesoscale Discussion | SPC | 36 min |
| Jun 11, 3:19 AM CDT | Mesoscale Discussion | SPC | 116 min |
| Jun 17, 2:05 PM CDT | Severe Thunderstorm Warning | FSD | 40 min |
| Jun 17, 2:44 PM CDT | Severe Thunderstorm Warning | FSD | 46 min |
| Jun 17, 3:29 PM CDT | Severe Thunderstorm Warning | FSD | 31 min |
| Jun 17, 3:54 PM CDT | Mesoscale Discussion | SPC | 66 min |
| Jun 17, 4:01 PM CDT | Severe Thunderstorm Warning | FSD | 44 min |
| Jun 17, 4:12 PM CDT | Severe Thunderstorm Warning | FSD | 33 min |
| Jun 17, 4:41 PM CDT | Severe Thunderstorm Warning | FSD | 49 min |
| Jun 17, 4:48 PM CDT | Severe Thunderstorm Warning | FSD | 57 min |
| Jun 17, 4:50 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 17, 6:55 PM CDT | Severe Thunderstorm Warning | FSD | 50 min |
| Jun 17, 7:53 PM CDT | Mesoscale Discussion | SPC | 67 min |
| Jun 20, 2:47 PM CDT | Severe Thunderstorm Warning | FSD | 43 min |
| Jun 21, 3:05 PM CDT | Mesoscale Discussion | SPC | 85 min |
| Jun 21, 5:03 PM CDT | Severe Thunderstorm Watch | SPC | 3 hr |
| Jun 21, 7:41 PM CDT | Mesoscale Discussion | SPC | 64 min |
| Jun 25, 1:36 AM CDT | Mesoscale Discussion | SPC | 84 min |
| Jun 25, 2:49 AM CDT | Severe Thunderstorm Warning | FSD | 26 min |
| Jun 25, 8:31 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 25, 11:18 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Jun 26, 2:28 AM CDT | Severe Thunderstorm Warning | FSD | 32 min |
| Jun 26, 6:38 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 26, 7:51 AM CDT | Mesoscale Discussion | SPC | 84 min |
| Jun 26, 7:14 PM CDT | Tornado Watch | SPC | 7 hr |
| Jun 26, 9:46 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 28, 3:06 AM CDT | Wind Advisory | FSD | 18 hr |
| Jul 10, 12:58 AM CDT | Severe Thunderstorm Warning | FSD | 47 min |
| Jul 10, 1:05 AM CDT | Flash Flood Warning | FSD | 115 min |
| Jul 10, 1:41 AM CDT | Severe Thunderstorm Warning | FSD | 49 min |
| Jul 16, 7:50 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 16, 11:54 PM CDT | Mesoscale Discussion | SPC | 96 min |
| Jul 18, 9:58 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 18, 11:47 PM CDT | Mesoscale Discussion | SPC | 88 min |
| Jul 19, 1:09 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 20, 7:58 PM CDT | Mesoscale Discussion | SPC | 92 min |
| Jul 20, 8:58 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 24, 3:04 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 24, 9:08 PM CDT | Mesoscale Discussion | SPC | 67 min |
| Jul 26, 8:51 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Jul 26, 11:15 PM CDT | Mesoscale Discussion | SPC | 90 min |
| Jul 26, 11:34 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 27, 2:25 AM CDT | Mesoscale Discussion | SPC | 95 min |
| Jul 28, 7:26 PM CDT | Severe Thunderstorm Warning | FSD | 49 min |
| Jul 28, 7:55 PM CDT | Tornado Warning | FSD | 50 min |
| Jul 28, 8:09 PM CDT | Severe Thunderstorm Warning | FSD | 66 min |
| Jul 30, 5:18 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Jul 30, 7:39 PM CDT | Tornado Warning | FSD | 36 min |
| Jul 30, 8:11 PM CDT | Severe Thunderstorm Warning | FSD | 34 min |
| Aug 2, 10:13 PM CDT | Mesoscale Discussion | SPC | 62 min |
| Aug 2, 11:13 PM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Aug 11, 2:58 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 11, 5:58 PM CDT | Severe Thunderstorm Warning | FSD | 38 min |
| Aug 13, 2:40 PM CDT | Severe Thunderstorm Warning | FSD | 35 min |
| Aug 13, 3:52 PM CDT | Severe Thunderstorm Warning | FSD | 38 min |
| Aug 13, 4:30 PM CDT | Severe Thunderstorm Warning | FSD | 45 min |
| Aug 13, 5:12 PM CDT | Flash Flood Warning | FSD | 2 hr |
| Aug 13, 5:16 PM CDT | Severe Thunderstorm Warning | FSD | 44 min |
| Aug 14, 3:55 PM CDT | Severe Thunderstorm Warning | FSD | 35 min |
| Aug 14, 4:45 PM CDT | Mesoscale Discussion | SPC | 90 min |
| Aug 14, 5:05 PM CDT | Severe Thunderstorm Warning | FSD | 14 min |
| Aug 31, 3:46 AM CDT | Wind Advisory | FSD | 15 hr |
| Sep 1, 2:18 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Sep 22, 8:27 PM CDT | Mesoscale Discussion | SPC | 93 min |
| Sep 24, 11:04 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Sep 28, 3:34 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Sep 28, 4:59 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Oct 4, 3:18 AM CDT | Wind Advisory | FSD | 12 hr |
| Oct 13, 3:32 AM CDT | Frost Advisory | FSD | 12 hr |
| Oct 13, 3:33 PM CDT | Freeze Warning | FSD | 17 hr |
| Oct 25, 1:41 PM CDT | High Wind Watch | FSD | 14 hr |
| Oct 26, 3:49 AM CDT | High Wind Warning | FSD | 16 hr |
| Nov 4, 3:30 PM CST | Winter Storm Watch | FSD | 20 hr |
| Nov 5, 11:23 AM CST | Blizzard Watch | FSD | 16 hr |
| Nov 6, 3:30 AM CST | Wind Advisory | FSD | 39 hr |
| Nov 6, 3:45 AM CST | Blizzard Warning | FSD | 24 hr |
| Nov 6, 3:45 AM CST | Winter Weather Advisory | FSD | 38 hr |
| Nov 10, 11:06 AM CST | Winter Weather Advisory | FSD | 27 hr |
| Nov 13, 2:49 PM CST | Wind Advisory | FSD | 27 hr |
| Dec 2, 3:10 PM CST | Winter Weather Advisory | FSD | 12 hr |
| Dec 8, 4:34 AM CST | Winter Weather Advisory | FSD | 23 hr |
| Dec 12, 3:25 AM CST | Blizzard Watch | FSD | 37 hr |
| Dec 13, 4:01 PM CST | Blizzard Warning | FSD | 32 hr |
| Dec 14, 12:07 AM CST | Mesoscale Discussion | SPC | 4 hr |
| Dec 14, 3:50 PM CST | Wind Chill Warning | FSD | 24 hr |
| Dec 18, 3:39 PM CST | Blizzard Watch | FSD | 24 hr |
| Dec 18, 6:37 PM CST | Mesoscale Discussion | SPC | 5 hr |
| Dec 19, 4:25 AM CST | Winter Weather Advisory | FSD | 32 hr |
| Dec 19, 4:08 PM CST | Blizzard Warning | FSD | 47 hr |
| Dec 20, 3:59 PM CST | Wind Chill Warning | FSD | 29 hr |
| Dec 29, 3:04 PM CST | Wind Advisory | FSD | 20 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20072009
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.