Alert archive / South Dakota / Dewey County
Weather alerts in Dewey County, South Dakota, 2009
135 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Dewey County and its neighbors
Each county as a circle sized by its count in 2009. Tap one for its archive.
- Alerts
- 135
- Warnings
- 51
- Watches
- 23
- Advisories
- 27
- Busiest month
- June33 alerts
- Busiest day
- July 9, 200912 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Dewey County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 28 | 10 | 64% | 11 | 91% | 35 min |
| Flash flood warnings | 3 | 2 | 33% | 3 | 100% | 34 min |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Aberdeen, SD: tornado warnings | 24 | 7 | 71% | 10 | 80% | 19 min |
| NWS Aberdeen, SD: severe thunderstorm warnings | 147 | 86 | 41% | 173 | 71% | 19 min |
| NWS Aberdeen, SD: flash flood warnings | 18 | 8 | 56% | 25 | 72% | 60 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, Mountain Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 3, 1:57 PM MST | Wind Chill Advisory | ABR | 20 hr |
| Jan 8, 3:58 AM MST | Winter Weather Advisory | ABR | 34 hr |
| Jan 9, 3:22 AM MST | Wind Advisory | ABR | 11 hr |
| Jan 11, 1:54 PM MST | Blizzard Warning | ABR | 27 hr |
| Jan 12, 4:34 AM MST | Mesoscale Discussion | SPC | 4 hr |
| Jan 12, 9:56 AM MST | Mesoscale Discussion | SPC | 6 hr |
| Jan 12, 11:08 AM MST | Wind Advisory | ABR | 2 hr |
| Jan 13, 6:47 PM MST | Wind Chill Advisory | ABR | 24 hr |
| Jan 31, 1:08 PM MST | Wind Advisory | ABR | 5 hr |
| Feb 1, 2:59 AM MST | Wind Advisory | ABR | 7 hr |
| Feb 8, 10:02 AM MST | Winter Storm Watch | ABR | 27 hr |
| Feb 9, 9:02 AM MST | Winter Storm Warning | ABR | 24 hr |
| Feb 9, 9:12 PM MST | Areal Flood Warning | ABR | 11 hr |
| Feb 17, 3:33 AM MST | Dense Fog Advisory | ABR | 5 hr |
| Feb 20, 1:32 AM MST | Wind Advisory | ABR | 15 hr |
| Feb 24, 2:16 PM MST | Winter Storm Watch | ABR | 12 hr |
| Feb 25, 2:41 AM MST | Winter Storm Warning | ABR | 40 hr |
| Feb 25, 9:20 PM MST | Mesoscale Discussion | SPC | 6 hr |
| Feb 27, 8:09 AM MST | Winter Weather Advisory | ABR | 9 hr |
| Mar 8, 10:42 AM MDT | Winter Storm Watch | ABR | 28 hr |
| Mar 9, 10:36 AM MDT | River Flood Warning | ABR | 11 hr |
| Mar 9, 2:23 PM MDT | Winter Storm Warning | ABR | 32 hr |
| Mar 10, 1:22 PM MDT | Wind Chill Advisory | ABR | 22 hr |
| Mar 17, 6:29 AM MDT | River Flood Warning | ABR | 5 days |
| Mar 21, 11:08 AM MDT | Blizzard Watch | ABR | 26 hr |
| Mar 22, 8:22 AM MDT | River Flood Warning | ABR | 32 hr |
| Mar 22, 1:10 PM MDT | Blizzard Warning | ABR | 55 hr |
| Mar 23, 5:56 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Mar 24, 7:46 AM MDT | River Flood Warning | ABR | 7 hr |
| Mar 25, 8:45 AM MDT | Areal Flood Advisory | ABR | 6 days |
| Mar 28, 3:37 AM MDT | Blizzard Watch | ABR | 35 hr |
| Mar 29, 3:30 AM MDT | Blizzard Warning | ABR | 65 hr |
| Mar 30, 5:36 AM MDT | Mesoscale Discussion | SPC | 4 hr |
| Mar 30, 2:20 PM MDT | Mesoscale Discussion | SPC | 6 hr |
| Apr 2, 2:23 PM MDT | Winter Storm Watch | ABR | 13 hr |
| Apr 3, 3:37 AM MDT | Winter Storm Warning | ABR | 41 hr |
| Apr 12, 10:00 AM MDT | River Flood Warning | ABR | 6 days |
| Apr 15, 10:27 AM MDT | Wind Advisory | ABR | 8 hr |
| Apr 28, 2:58 AM MDT | Wind Advisory | ABR | 11 hr |
| Apr 29, 4:22 PM MDT | Special Weather Statement | ABR | 68 min |
| May 12, 2:19 PM MDT | Mesoscale Discussion | SPC | 56 min |
| May 12, 2:36 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 12, 3:00 PM MDT | High Wind Watch | ABR | 11 hr |
| May 12, 4:54 PM MDT | Mesoscale Discussion | SPC | 96 min |
| May 12, 5:44 PM MDT | Severe Thunderstorm Warning | ABR | 61 min |
| May 12, 6:34 PM MDT | Severe Thunderstorm Warning | ABR | 41 min |
| May 13, 2:27 AM MDT | High Wind Warning | ABR | 18 hr |
| May 13, 8:04 PM MDT | Wind Advisory | ABR | 2 hr |
| May 15, 2:23 PM MDT | Freeze Warning | ABR | 17 hr |
| May 28, 4:18 PM MDT | Severe Thunderstorm Warning | ABR | 27 min |
| May 29, 5:15 PM MDT | Mesoscale Discussion | SPC | 60 min |
| May 29, 5:45 PM MDT | Severe Thunderstorm Warning | ABR | 45 min |
| May 29, 6:24 PM MDT | Severe Thunderstorm Warning | ABR | 51 min |
| Jun 14, 4:09 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 14, 6:17 PM MDT | Mesoscale Discussion | SPC | 118 min |
| Jun 15, 3:08 PM MDT | Mesoscale Discussion | SPC | 67 min |
| Jun 15, 4:33 PM MDT | Severe Thunderstorm Warning | ABR | 42 min |
| Jun 15, 5:02 PM MDT | Flash Flood Warning | ABR | 58 min |
| Jun 15, 5:16 PM MDT | Severe Thunderstorm Warning | ABR | 59 min |
| Jun 15, 5:46 PM MDT | Severe Thunderstorm Warning | ABR | 59 min |
| Jun 15, 6:00 PM MDT | Flash Flood Warning | ABR | 2 hr |
| Jun 15, 6:44 PM MDT | Severe Thunderstorm Warning | ABR | 61 min |
| Jun 15, 7:13 PM MDT | Flash Flood Warning | ABR | 2 hr |
| Jun 15, 7:29 PM MDT | Severe Thunderstorm Warning | ABR | 46 min |
| Jun 15, 7:47 PM MDT | Severe Thunderstorm Warning | ABR | 13 min |
| Jun 15, 8:04 PM MDT | Areal Flood Warning | ABR | 3 hr |
| Jun 15, 8:17 PM MDT | Severe Thunderstorm Warning | ABR | 43 min |
| Jun 15, 8:22 PM MDT | Special Weather Statement | ABR | 38 min |
| Jun 16, 12:23 PM MDT | Mesoscale Discussion | SPC | 97 min |
| Jun 17, 4:02 PM MDT | Mesoscale Discussion | SPC | 88 min |
| Jun 17, 4:26 PM MDT | Mesoscale Discussion | SPC | 94 min |
| Jun 17, 5:35 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 17, 11:01 PM MDT | Mesoscale Discussion | SPC | 89 min |
| Jun 18, 12:50 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 18, 2:33 PM MDT | Special Weather Statement | ABR | 27 min |
| Jun 24, 6:14 AM MDT | Mesoscale Discussion | SPC | 91 min |
| Jun 24, 12:46 PM MDT | Mesoscale Discussion | SPC | 119 min |
| Jun 24, 5:16 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 24, 7:49 PM MDT | Mesoscale Discussion | SPC | 86 min |
| Jun 26, 2:31 AM MDT | Flash Flood Watch | ABR | 21 hr |
| Jun 26, 1:13 PM MDT | Mesoscale Discussion | SPC | 62 min |
| Jun 26, 1:53 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 26, 5:24 PM MDT | Tornado Watch | SPC | 4 hr |
| Jun 26, 6:30 PM MDT | Severe Thunderstorm Warning | ABR | 22 min |
| Jun 26, 7:05 PM MDT | Severe Thunderstorm Warning | ABR | 40 min |
| Jun 27, 4:02 PM MDT | Mesoscale Discussion | SPC | 58 min |
| Jul 8, 2:20 PM MDT | Tornado Watch | SPC | 8 hr |
| Jul 8, 5:46 PM MDT | Mesoscale Discussion | SPC | 89 min |
| Jul 8, 8:14 PM MDT | Severe Thunderstorm Warning | ABR | 61 min |
| Jul 8, 8:40 PM MDT | Severe Thunderstorm Warning | ABR | 65 min |
| Jul 8, 8:42 PM MDT | Mesoscale Discussion | SPC | 93 min |
| Jul 8, 8:58 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 8, 9:02 PM MDT | Severe Thunderstorm Warning | ABR | 26 min |
| Jul 8, 9:23 PM MDT | Severe Thunderstorm Warning | ABR | 52 min |
| Jul 8, 10:11 PM MDT | Severe Thunderstorm Warning | ABR | 64 min |
| Jul 8, 10:27 PM MDT | Mesoscale Discussion | SPC | 93 min |
| Jul 8, 10:52 PM MDT | Severe Thunderstorm Warning | ABR | 53 min |
| Jul 8, 11:13 PM MDT | Severe Thunderstorm Warning | ABR | 32 min |
| Jul 8, 11:35 PM MDT | Severe Thunderstorm Warning | ABR | 42 min |
| Jul 9, 2:07 AM MDT | Mesoscale Discussion | SPC | 83 min |
| Jul 13, 9:38 AM MDT | Mesoscale Discussion | SPC | 97 min |
| Jul 13, 9:57 AM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 13, 12:05 PM MDT | Severe Thunderstorm Warning | ABR | 55 min |
| Jul 13, 1:01 PM MDT | Severe Thunderstorm Warning | ABR | 44 min |
| Jul 13, 7:47 PM MDT | Mesoscale Discussion | SPC | 58 min |
| Jul 13, 8:42 PM MDT | Tornado Watch | SPC | 4 hr |
| Jul 13, 9:23 PM MDT | Severe Thunderstorm Warning | ABR | 34 min |
| Jul 13, 10:24 PM MDT | Mesoscale Discussion | SPC | 66 min |
| Jul 19, 6:28 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 19, 10:02 PM MDT | Mesoscale Discussion | SPC | 58 min |
| Aug 18, 4:58 PM MDT | Severe Thunderstorm Warning | ABR | 47 min |
| Aug 18, 5:44 PM MDT | Severe Thunderstorm Warning | ABR | 46 min |
| Aug 19, 11:16 AM MDT | Mesoscale Discussion | SPC | 119 min |
| Sep 2, 11:05 AM MDT | Areal Flood Advisory | ABR | 4 hr |
| Sep 4, 2:45 AM MDT | Dense Fog Advisory | ABR | 6 hr |
| Sep 10, 3:53 PM MDT | Mesoscale Discussion | SPC | 97 min |
| Sep 11, 12:36 AM MDT | Severe Thunderstorm Warning | ABR | 54 min |
| Sep 26, 2:08 PM MDT | Wind Advisory | ABR | 28 hr |
| Sep 28, 2:49 AM MDT | Frost Advisory | ABR | 29 hr |
| Sep 30, 10:07 AM MDT | Wind Advisory | ABR | 8 hr |
| Sep 30, 2:29 PM MDT | Wind Advisory | ABR | 48 hr |
| Oct 7, 1:23 PM MDT | Freeze Watch | ABR | 13 hr |
| Oct 8, 2:37 AM MDT | Freeze Warning | ABR | 30 hr |
| Oct 27, 2:37 PM MDT | Winter Storm Watch | ABR | 43 hr |
| Oct 28, 10:42 AM MDT | Winter Storm Warning | ABR | 23 hr |
| Oct 29, 9:39 AM MDT | Winter Weather Advisory | ABR | 4 hr |
| Dec 1, 2:46 AM MST | Wind Advisory | ABR | 14 hr |
| Dec 8, 2:30 PM MST | Wind Chill Advisory | ABR | 43 hr |
| Dec 13, 3:02 AM MST | Wind Chill Advisory | ABR | 8 hr |
| Dec 14, 2:52 PM MST | Wind Chill Advisory | ABR | 19 hr |
| Dec 21, 1:16 PM MST | Winter Storm Watch | ABR | 14 hr |
| Dec 22, 2:58 AM MST | Winter Storm Warning | ABR | 55 hr |
| Dec 24, 9:45 AM MST | Blizzard Warning | ABR | 55 hr |
| Dec 25, 6:21 AM MST | Mesoscale Discussion | SPC | 5 hr |
| Dec 26, 10:54 AM MST | Winter Weather Advisory | ABR | 12 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 archive20082010
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.