Alert archive / South Dakota / Fall River County
Weather alerts in Fall River County, South Dakota, 2020
126 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Fall River County and its neighbors
Each county as a circle sized by its count in 2020. Tap one for its archive.
- Alerts
- 126
- Warnings
- 41
- Watches
- 28
- Advisories
- 12
- Busiest month
- July38 alerts
- Busiest day
- July 9, 20208 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Fall River County, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 22 | 20 | 9% | 23 | 87% | 23 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Rapid City, SD: tornado warnings | 11 | 2 | 82% | 11 | 27% | 18 min |
| NWS Rapid City, SD: severe thunderstorm warnings | 415 | 336 | 19% | 828 | 89% | 27 min |
| NWS Rapid City, SD: flash flood warnings | 10 | 7 | 30% | 11 | 91% | 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, Mountain Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 1, 2:52 AM MST | Wind Advisory | UNR | 11 hr |
| Feb 2, 2:37 AM MST | Winter Weather Advisory | UNR | 44 hr |
| Feb 14, 11:17 AM MST | Wind Advisory | UNR | 4 hr |
| Feb 24, 2:28 AM MST | Winter Weather Advisory | UNR | 36 hr |
| Mar 5, 2:00 PM MST | Fire Weather Watch | UNR | 36 hr |
| Mar 7, 2:19 AM MST | Red Flag Warning | UNR | 16 hr |
| Mar 10, 2:39 PM MDT | Fire Weather Watch | UNR | 12 hr |
| Mar 11, 2:53 AM MDT | Red Flag Warning | UNR | 16 hr |
| Mar 12, 2:10 PM MDT | Winter Storm Watch | UNR | 13 hr |
| Mar 13, 3:13 AM MDT | Winter Storm Warning | UNR | 29 hr |
| Mar 13, 3:13 AM MDT | Winter Weather Advisory | UNR | 32 hr |
| Mar 16, 2:09 PM MDT | Winter Storm Watch | UNR | 49 hr |
| Mar 18, 2:10 AM MDT | Winter Weather Advisory | UNR | 40 hr |
| Mar 31, 2:05 PM MDT | Winter Weather Advisory | UNR | 58 hr |
| Apr 5, 1:56 PM MDT | Fire Weather Watch | UNR | 15 hr |
| Apr 6, 4:30 AM MDT | Red Flag Warning | UNR | 38 hr |
| Apr 9, 2:02 AM MDT | Winter Storm Watch | UNR | 37 hr |
| Apr 10, 2:35 PM MDT | Winter Storm Warning | UNR | 42 hr |
| Apr 27, 1:44 PM MDT | Wind Advisory | UNR | 30 hr |
| Apr 30, 6:56 PM MDT | Special Weather Statement | UNR | 49 min |
| Apr 30, 7:41 PM MDT | Special Weather Statement | UNR | 49 min |
| Apr 30, 7:56 PM MDT | Severe Thunderstorm Warning | UNR | 34 min |
| May 3, 5:26 PM MDT | Special Weather Statement | UNR | 49 min |
| May 3, 6:33 PM MDT | Special Weather Statement | UNR | 42 min |
| May 13, 5:21 PM MDT | Special Weather Statement | UNR | 24 min |
| May 15, 3:42 PM MDT | Special Weather Statement | UNR | 48 min |
| May 20, 1:07 PM MDT | Mesoscale Discussion | SPC | 83 min |
| May 20, 2:22 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| May 20, 5:25 PM MDT | Mesoscale Discussion | SPC | 95 min |
| May 23, 12:48 PM MDT | Mesoscale Discussion | SPC | 117 min |
| May 23, 1:15 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 23, 2:57 PM MDT | Mesoscale Discussion | SPC | 93 min |
| May 23, 5:27 PM MDT | Mesoscale Discussion | SPC | 93 min |
| May 31, 3:43 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 2, 2:23 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 2, 6:35 PM MDT | Mesoscale Discussion | SPC | 85 min |
| Jun 3, 12:35 PM MDT | Mesoscale Discussion | SPC | 85 min |
| Jun 4, 8:46 PM MDT | Severe Thunderstorm Warning | UNR | 59 min |
| Jun 5, 7:01 PM MDT | Mesoscale Discussion | SPC | 119 min |
| Jun 6, 1:13 PM MDT | Special Weather Statement | UNR | 32 min |
| Jun 6, 2:33 PM MDT | Mesoscale Discussion | SPC | 117 min |
| Jun 6, 4:49 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 6, 5:09 PM MDT | Severe Thunderstorm Warning | UNR | 66 min |
| Jun 6, 5:25 PM MDT | Mesoscale Discussion | SPC | 95 min |
| Jun 6, 5:56 PM MDT | Severe Thunderstorm Warning | UNR | 49 min |
| Jun 6, 6:45 PM MDT | Severe Thunderstorm Warning | UNR | 60 min |
| Jun 13, 8:41 PM MDT | Special Weather Statement | UNR | 49 min |
| Jun 20, 1:08 PM MDT | Special Weather Statement | UNR | 52 min |
| Jun 21, 1:05 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 21, 6:00 PM MDT | Special Weather Statement | UNR | 60 min |
| Jun 21, 6:26 PM MDT | Severe Thunderstorm Warning | UNR | 29 min |
| Jul 1, 4:00 AM MDT | Red Flag Warning | UNR | 16 hr |
| Jul 2, 1:15 PM MDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jul 2, 3:58 PM MDT | Severe Thunderstorm Warning | UNR | 62 min |
| Jul 4, 4:40 PM MDT | Severe Thunderstorm Warning | UNR | 49 min |
| Jul 4, 4:57 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 4, 5:37 PM MDT | Special Weather Statement | UNR | 38 min |
| Jul 5, 3:00 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 5, 4:13 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 5, 6:19 PM MDT | Severe Thunderstorm Warning | UNR | 19 min |
| Jul 5, 6:24 PM MDT | Mesoscale Discussion | SPC | 66 min |
| Jul 5, 6:48 PM MDT | Special Weather Statement | CYS | 42 min |
| Jul 5, 7:09 PM MDT | Severe Thunderstorm Warning | UNR | 66 min |
| Jul 6, 1:55 PM MDT | Fire Weather Watch | UNR | 13 hr |
| Jul 6, 2:45 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 7, 3:07 AM MDT | Red Flag Warning | UNR | 17 hr |
| Jul 7, 2:35 PM MDT | Fire Weather Watch | UNR | 12 hr |
| Jul 7, 2:50 PM MDT | Mesoscale Discussion | SPC | 85 min |
| Jul 9, 3:20 AM MDT | Severe Thunderstorm Warning | UNR | 55 min |
| Jul 9, 3:46 AM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 9, 4:10 AM MDT | Severe Thunderstorm Warning | UNR | 65 min |
| Jul 9, 5:00 AM MDT | Severe Thunderstorm Warning | UNR | 60 min |
| Jul 9, 5:03 AM MDT | Special Weather Statement | UNR | 42 min |
| Jul 9, 6:03 AM MDT | Special Weather Statement | UNR | 42 min |
| Jul 9, 12:51 PM MDT | Mesoscale Discussion | SPC | 114 min |
| Jul 9, 2:33 PM MDT | Fire Weather Watch | UNR | 12 hr |
| Jul 9, 8:17 PM MDT | Severe Thunderstorm Warning | UNR | 58 min |
| Jul 10, 2:26 AM MDT | Red Flag Warning | UNR | 17 hr |
| Jul 10, 2:43 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 15, 2:31 AM MDT | Special Weather Statement | UNR | 44 min |
| Jul 16, 3:13 AM MDT | Fire Weather Watch | UNR | 16 hr |
| Jul 16, 7:39 PM MDT | Red Flag Warning | UNR | 24 hr |
| Jul 19, 2:50 PM MDT | Mesoscale Discussion | SPC | 115 min |
| Jul 19, 4:06 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 19, 6:48 PM MDT | Mesoscale Discussion | SPC | 117 min |
| Jul 20, 12:13 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 20, 2:19 PM MDT | Mesoscale Discussion | SPC | 116 min |
| Jul 23, 2:55 AM MDT | Red Flag Warning | UNR | 17 hr |
| Jul 27, 1:54 PM MDT | Flash Flood Watch | UNR | 56 hr |
| Aug 1, 2:33 PM MDT | Special Weather Statement | UNR | 42 min |
| Aug 6, 5:13 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 8, 1:31 PM MDT | Mesoscale Discussion | SPC | 119 min |
| Aug 8, 4:57 PM MDT | Severe Thunderstorm Warning | UNR | 35 min |
| Aug 8, 5:00 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 8, 5:05 PM MDT | Severe Thunderstorm Warning | UNR | 28 min |
| Aug 8, 6:16 PM MDT | Severe Thunderstorm Warning | UNR | 44 min |
| Aug 8, 6:45 PM MDT | Severe Thunderstorm Warning | UNR | 45 min |
| Aug 11, 4:03 PM MDT | Severe Thunderstorm Warning | UNR | 42 min |
| Aug 11, 5:40 PM MDT | Severe Thunderstorm Warning | UNR | 44 min |
| Aug 11, 5:42 PM MDT | Severe Thunderstorm Warning | UNR | 18 min |
| Aug 12, 3:40 AM MDT | Fire Weather Watch | UNR | 10 hr |
| Aug 12, 3:40 AM MDT | Red Flag Warning | UNR | 40 hr |
| Aug 17, 4:15 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 19, 6:19 PM MDT | Special Weather Statement | UNR | 41 min |
| Aug 27, 4:52 PM MDT | Mesoscale Discussion | SPC | 83 min |
| Aug 27, 5:31 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 27, 6:08 PM MDT | Severe Thunderstorm Warning | UNR | 67 min |
| Aug 30, 1:40 PM MDT | Fire Weather Watch | UNR | 48 hr |
| Sep 1, 2:59 AM MDT | Red Flag Warning | UNR | 42 hr |
| Sep 3, 4:00 AM MDT | Fire Weather Watch | UNR | 33 hr |
| Sep 4, 12:56 PM MDT | Red Flag Warning | UNR | 54 hr |
| Sep 8, 2:34 AM MDT | Mesoscale Discussion | SPC | 4 hr |
| Sep 8, 1:51 PM MDT | Freeze Warning | UNR | 18 hr |
| Sep 12, 1:44 PM MDT | Fire Weather Watch | UNR | 24 hr |
| Sep 13, 2:03 PM MDT | Red Flag Warning | UNR | 30 hr |
| Sep 22, 2:03 PM MDT | Fire Weather Watch | UNR | 36 hr |
| Sep 26, 7:32 PM MDT | Wind Advisory | UNR | 23 hr |
| Oct 7, 1:30 PM MDT | Red Flag Warning | UNR | 29 hr |
| Oct 9, 3:12 AM MDT | Fire Weather Watch | UNR | 11 hr |
| Oct 9, 2:06 PM MDT | Red Flag Warning | UNR | 29 hr |
| Oct 13, 1:50 PM MDT | High Wind Warning | UNR | 28 hr |
| Oct 22, 2:42 PM MDT | Winter Storm Watch | UNR | 23 hr |
| Oct 23, 2:05 PM MDT | Winter Weather Advisory | UNR | 47 hr |
| Nov 13, 2:14 PM MST | Wind Advisory | UNR | 32 hr |
| Dec 22, 3:13 AM MST | High Wind Warning | UNR | 34 hr |
| Dec 28, 3:06 AM MST | Winter Weather Advisory | UNR | 37 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 | 22 |
| Severe Thunderstorm Watch | 10 |
| Mesoscale Discussion | 28 |
| Special Weather Statement | 17 |
| Flooding | |
| Flash Flood Watch | 1 |
| Winter | |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 4 |
| Winter Weather Advisory | 7 |
| Cold | |
| Freeze Warning | 1 |
| Wind and dust | |
| High Wind Warning | 2 |
| Wind Advisory | 5 |
| Fire | |
| Red Flag Warning | 14 |
| Fire Weather Watch | 13 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20192021
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.