Weather alerts in South Dakota, 2014
1,551 weather alerts in 2014, 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 2014. Tap one for its archive.
- Alerts
- 1,551
- Warnings
- 708
- Watches
- 106
- Advisories
- 294
- Busiest month
- June586 alerts
- Busiest day
- June 18, 201489 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
23 of 43 tornado warnings covering South Dakota in 2014 had a tornado report inside them; 41 of 54 tornado reports fell inside a warning, on average 17 minutes after it went out.
South Dakota, 2014
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 43 | 23 | 47% | 54 | 76% | 17 min |
| Severe thunderstorm warnings | 461 | 303 | 34% | 538 | 82% | 20 min |
| Flash flood warnings | 57 | 37 | 35% | 48 | 96% | 101 min |
Each office's whole area, 2014
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Sioux Falls, SD: tornado warnings | 46 | 22 | 52% | 52 | 85% | 19 min |
| NWS Sioux Falls, SD: severe thunderstorm warnings | 216 | 124 | 43% | 250 | 85% | 17 min |
| NWS Sioux Falls, SD: flash flood warnings | 39 | 17 | 56% | 24 | 92% | 112 min |
| NWS Aberdeen, SD: tornado warnings | 15 | 8 | 47% | 15 | 73% | 12 min |
| NWS Aberdeen, SD: severe thunderstorm warnings | 141 | 78 | 45% | 133 | 75% | 19 min |
| NWS Aberdeen, SD: flash flood warnings | 31 | 22 | 29% | 35 | 97% | 104 min |
| NWS Rapid City, SD: tornado warnings | 11 | 5 | 55% | 10 | 50% | 7 min |
| NWS Rapid City, SD: severe thunderstorm warnings | 277 | 214 | 23% | 385 | 86% | 22 min |
| NWS Rapid City, SD: flash flood warnings | 10 | 5 | 50% | 8 | 75% | 68 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
1,551 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.
| Product | Alerts |
|---|---|
| Severe storms | |
| Severe Thunderstorm Warning | 461 |
| Tornado Warning | 43 |
| Severe Thunderstorm Watch | 32 |
| Tornado Watch | 13 |
| Mesoscale Discussion | 166 |
| Special Weather Statement | 277 |
| Flooding | |
| Areal Flood Warning | 22 |
| Flash Flood Warning | 57 |
| River Flood Warning | 41 |
| Flash Flood Watch | 15 |
| Flood Watch | 3 |
| Areal Flood Advisory | 30 |
| Winter | |
| Blizzard Warning | 14 |
| Winter Storm Warning | 19 |
| Blizzard Watch | 5 |
| Winter Storm Watch | 17 |
| Freezing Rain Advisory | 9 |
| Winter Weather Advisory | 77 |
| Heat | |
| Heat Advisory | 3 |
| Cold | |
| Freeze Warning | 10 |
| Wind Chill Warning | 11 |
| Wind Chill Watch | 1 |
| Frost Advisory | 11 |
| Wind Chill Advisory | 54 |
| Wind and dust | |
| High Wind Warning | 18 |
| High Wind Watch | 12 |
| Wind Advisory | 97 |
| Fire | |
| Red Flag Warning | 12 |
| Fire Weather Watch | 8 |
| Fog and smoke | |
| Dense Fog Advisory | 13 |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Pennington County264
- Meade County235
- Lawrence County196
- Custer County195
- Butte County175
- Harding County164
- Union County156
- Perkins County154
- Haakon County147
- Fall River County144
- Minnehaha County143
- Lincoln County142
- Ziebach County139
- Edmunds County136
- McPherson County133
- Clay County131
- Dewey County128
- Bennett County128
- Jackson County127
- Roberts County126
- Corson County125
- Brown County120
- Campbell County118
- Walworth County118
- Deuel County116
- Grant County115
- Faulk County115
- Stanley County114
- Day County113
- Todd County113
- Spink County112
- Moody County111
- Marshall County110
- Brookings County109
- Codington County107
- Potter County107
- Clark County106
- Hamlin County106
- Hand County106
- Oglala Lakota County104
26 more counties
- Turner County103
- Yankton County102
- Hughes County102
- Sully County102
- McCook County100
- Lake County99
- Mellette County99
- Miner County96
- Hyde County96
- Kingsbury County95
- Hanson County93
- Hutchinson County93
- Beadle County88
- Sanborn County87
- Lyman County86
- Davison County85
- Tripp County84
- Jones County83
- Bon Homme County82
- Douglas County81
- Charles Mix County79
- Jerauld County77
- Aurora County76
- Buffalo County75
- Brule County70
- Gregory County67
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20132015
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.