Weather alerts in South Dakota, 2023
1,800 weather alerts in 2023, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered any part of the state, so the counties below add up to more than the state.
Weather alerts by county
Each county as a circle sized by its count in 2023. Tap one for its archive.
- Alerts
- 1,800
- Warnings
- 739
- Watches
- 79
- Advisories
- 276
- Busiest month
- July480 alerts
- Busiest day
- June 24, 202384 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
6 of 16 tornado warnings covering South Dakota in 2023 had a tornado report inside them; 8 of 17 tornado reports fell inside a warning, on average 15 minutes after it went out.
South Dakota, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 16 | 6 | 63% | 17 | 47% | 15 min |
| Severe thunderstorm warnings | 541 | 354 | 35% | 736 | 81% | 23 min |
| Flash flood warnings | 14 | 6 | 57% | 14 | 93% | 84 min |
Each office's whole area, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Rapid City, SD: tornado warnings | 6 | 2 | 67% | 5 | 60% | 18 min |
| NWS Rapid City, SD: severe thunderstorm warnings | 331 | 236 | 29% | 532 | 82% | 24 min |
| NWS Rapid City, SD: flash flood warnings | 11 | 5 | 55% | 12 | 92% | 78 min |
| NWS Aberdeen, SD: tornado warnings | 6 | 3 | 50% | 7 | 57% | 18 min |
| NWS Aberdeen, SD: severe thunderstorm warnings | 126 | 71 | 44% | 157 | 73% | 23 min |
| NWS Aberdeen, SD: flash flood warnings | 1 | 0 | 100% | 0 | ||
| NWS Sioux Falls, SD: tornado warnings | 23 | 6 | 74% | 16 | 50% | 13 min |
| NWS Sioux Falls, SD: severe thunderstorm warnings | 228 | 126 | 45% | 282 | 82% | 18 min |
| NWS Sioux Falls, SD: flash flood warnings | 9 | 3 | 67% | 12 | 75% | 47 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
1,800 alerts are too many to list on one page. Narrow it to a product above, to a month in the chart, or to a county.
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Pennington County297
- Custer County250
- Meade County217
- Lawrence County187
- Oglala Lakota County181
- Fall River County158
- Jackson County157
- Todd County156
- Bennett County154
- Mellette County141
- Yankton County132
- Hutchinson County131
- Butte County130
- Tripp County129
- Haakon County128
- Union County127
- Turner County127
- Bon Homme County126
- Stanley County121
- Lincoln County120
- Lyman County119
- Davison County119
- Jones County117
- Clay County115
- Brown County115
- Charles Mix County114
- Hughes County113
- Hanson County112
- Harding County112
- Douglas County111
- Aurora County110
- Corson County110
- Spink County109
- Hyde County108
- Hand County107
- McCook County107
- Minnehaha County107
- Clark County105
- Faulk County105
- Codington County104
26 more counties
- Brule County104
- Buffalo County103
- Gregory County103
- Moody County102
- Day County101
- Sanborn County101
- Grant County99
- Roberts County99
- Sully County99
- Beadle County99
- Marshall County98
- Ziebach County98
- Lake County95
- Hamlin County94
- Potter County94
- Kingsbury County94
- Campbell County94
- Dewey County94
- McPherson County94
- Brookings County93
- Jerauld County93
- Edmunds County93
- Deuel County92
- Miner County92
- Perkins County90
- Walworth County90
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20222024
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.