Alert archive / South Dakota / Flash Flood Warnings
Flash Flood Warnings in South Dakota, 2010
75 flash flood warnings in 2010. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of flash flood warnings reaches back to 1986.
Flash Flood Warnings by county
Each county as a circle sized by its count in 2010. Tap one for its archive.
- Flash Flood Warnings
- 75
- Busiest month
- June27 flash flood warnings
- Busiest day
- July 30, 20107 flash flood warnings
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
57 of 75 flash flood warnings covering South Dakota in 2010 had a flash flood report inside them; 90 of 98 flash flood reports fell inside a warning, on average 81 minutes after it went out.
South Dakota, 2010
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Flash flood warnings | 75 | 57 | 24% | 98 | 92% | 81 min |
Each office's whole area, 2010
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Sioux Falls, SD: flash flood warnings | 77 | 62 | 19% | 124 | 91% | 64 min |
| NWS Rapid City, SD: flash flood warnings | 9 | 5 | 44% | 22 | 95% | 110 min |
| NWS Aberdeen, SD: flash flood warnings | 18 | 10 | 44% | 16 | 81% | 111 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 | Counties | Lasted |
|---|---|---|---|---|
| Apr 24, 5:03 PM CDT | Flash Flood Warning | FSD | Minnehaha | 2 hr |
| Apr 24, 5:26 PM CDT | Flash Flood Warning | FSD | Minnehaha | 102 min |
| May 22, 8:55 PM CDT | Flash Flood Warning | ABR | Brown, Edmunds, Faulk, McPherson, Marshall, Spink | 3 hr |
| May 24, 4:00 PM CDT | Flash Flood Warning | UNR | Pennington | 5 hr |
| May 24, 4:15 PM CDT | Flash Flood Warning | UNR | Meade, Pennington | 5 hr |
| May 24, 4:56 PM CDT | Flash Flood Warning | UNR | Custer, Pennington | 4 hr |
| May 29, 9:36 PM CDT | Flash Flood Warning | ABR | Campbell, Edmunds, McPherson, Potter, Walworth | 3 hr |
| Jun 1, 8:44 AM CDT | Flash Flood Warning | FSD | Aurora, Brule, Charles Mix, Douglas, Gregory | 102 min |
| Jun 1, 9:03 AM CDT | Flash Flood Warning | FSD | Aurora, Brule, Charles Mix, Davison, Douglas, Hutchinson | 2 hr |
| Jun 11, 12:26 AM CDT | Flash Flood Warning | FSD | Aurora, Jerauld, Sanborn | 3 hr |
| Jun 11, 1:23 AM CDT | Flash Flood Warning | FSD | Davison, Hanson, McCook, Miner, Sanborn | 3 hr |
| Jun 11, 2:39 AM CDT | Flash Flood Warning | FSD | Bon Homme, Clay, Hutchinson, Lincoln, Turner, Yankton | 3 hr |
| Jun 11, 2:43 AM CDT | Flash Flood Warning | FSD | Lincoln, Minnehaha, Turner | 3 hr |
| Jun 11, 3:17 AM CDT | Flash Flood Warning | FSD | Union | 3 hr |
| Jun 11, 3:32 AM CDT | Flash Flood Warning | FSD | Brookings, Lake, Moody | 3 hr |
| Jun 12, 6:09 AM CDT | Flash Flood Warning | FSD | Aurora, Bon Homme, Charles Mix, Davison, Douglas, Gregory and 2 more | 6 hr |
| Jun 13, 7:49 PM CDT | Flash Flood Warning | UNR | Lawrence, Pennington | 2 hr |
| Jun 16, 7:12 PM CDT | Flash Flood Warning | UNR | Ziebach | 6 hr |
| Jun 16, 7:58 PM CDT | Flash Flood Warning | UNR | Ziebach | 11 hr |
| Jun 16, 8:32 PM CDT | Flash Flood Warning | ABR | Dewey | 3 hr |
| Jun 16, 10:22 PM CDT | Flash Flood Warning | UNR | Ziebach | 9 hr |
| Jun 16, 11:26 PM CDT | Flash Flood Warning | ABR | Dewey | 9 hr |
| Jun 22, 10:35 PM CDT | Flash Flood Warning | ABR | Hughes, Jones, Lyman, Stanley, Sully | 6 hr |
| Jun 22, 11:03 PM CDT | Flash Flood Warning | ABR | Buffalo, Hand, Hyde | 6 hr |
| Jun 22, 11:13 PM CDT | Flash Flood Warning | FSD | Clay, Yankton | 3 hr |
| Jun 23, 12:21 AM CDT | Flash Flood Warning | FSD | Lincoln, Union | 5 hr |
| Jun 26, 3:24 PM CDT | Flash Flood Warning | ABR | Clark, Codington, Deuel, Hamlin | 3 hr |
| Jun 26, 4:11 PM CDT | Flash Flood Warning | ABR | Buffalo, Hand | 3 hr |
| Jun 26, 4:43 PM CDT | Flash Flood Warning | FSD | Beadle, Jerauld, Sanborn | 3 hr |
| Jun 26, 5:35 PM CDT | Flash Flood Warning | FSD | Kingsbury, Lake, Miner | 3 hr |
| Jun 26, 6:24 PM CDT | Flash Flood Warning | ABR | Clark, Codington, Deuel, Hamlin | 4 hr |
| Jun 26, 6:29 PM CDT | Flash Flood Warning | FSD | Brookings, Lake, Moody | 3 hr |
| Jun 26, 7:03 PM CDT | Flash Flood Warning | FSD | Lincoln, Minnehaha, Turner | 3 hr |
| Jun 26, 8:50 PM CDT | Flash Flood Warning | ABR | Faulk, Hyde, Potter, Sully | 75 min |
| Jul 5, 4:01 PM CDT | Flash Flood Warning | FSD | Minnehaha, Moody | 3 hr |
| Jul 6, 9:38 PM CDT | Flash Flood Warning | FSD | Aurora, Brule | 3 hr |
| Jul 6, 9:48 PM CDT | Flash Flood Warning | ABR | Hand, Hyde | 57 min |
| Jul 6, 10:57 PM CDT | Flash Flood Warning | ABR | Faulk, Hand, Hyde | 4 hr |
| Jul 6, 11:13 PM CDT | Flash Flood Warning | ABR | Clark, Spink | 5 hr |
| Jul 10, 5:13 PM CDT | Flash Flood Warning | ABR | Buffalo, Lyman | 3 hr |
| Jul 10, 7:48 PM CDT | Flash Flood Warning | FSD | Davison, Hanson | 87 min |
| Jul 10, 9:13 PM CDT | Flash Flood Warning | FSD | Aurora, Brule, Charles Mix, Davison, Douglas | 65 min |
| Jul 17, 7:57 PM CDT | Flash Flood Warning | FSD | Brookings | 3 hr |
| Jul 19, 5:17 AM CDT | Flash Flood Warning | FSD | Union | 3 hr |
| Jul 21, 7:54 PM CDT | Flash Flood Warning | FSD | Davison, Hanson, Sanborn | 6 hr |
| Jul 21, 9:48 PM CDT | Flash Flood Warning | FSD | Lincoln, Minnehaha | 6 hr |
| Jul 21, 10:53 PM CDT | Flash Flood Warning | FSD | Lincoln, Minnehaha | 6 hr |
| Jul 21, 11:25 PM CDT | Flash Flood Warning | FSD | Clay, Lincoln, Turner, Union, Yankton | 7 hr |
| Jul 22, 2:08 AM CDT | Flash Flood Warning | FSD | Union | 4 hr |
| Jul 27, 9:55 PM CDT | Flash Flood Warning | FSD | Lincoln, Minnehaha | 2 hr |
| Jul 29, 1:22 PM CDT | Flash Flood Warning | FSD | Bon Homme, Charles Mix, Clay, Douglas, Hutchinson, Union and 1 more | 5 hr |
| Jul 29, 9:08 PM CDT | Flash Flood Warning | ABR | Buffalo, Hand, Hyde | 6 hr |
| Jul 29, 9:27 PM CDT | Flash Flood Warning | FSD | Beadle, Jerauld, Sanborn | 5 hr |
| Jul 29, 11:12 PM CDT | Flash Flood Warning | FSD | Davison, Hanson, Miner, Sanborn | 4 hr |
| Jul 30, 1:14 AM CDT | Flash Flood Warning | FSD | Lincoln, McCook, Minnehaha, Turner | 106 min |
| Jul 30, 2:04 AM CDT | Flash Flood Warning | FSD | Lincoln | 3 hr |
| Jul 30, 3:00 AM CDT | Flash Flood Warning | FSD | Clay, Union | 3 hr |
| Jul 30, 3:52 AM CDT | Flash Flood Warning | FSD | Union | 3 hr |
| Aug 2, 6:35 AM CDT | Flash Flood Warning | FSD | Lincoln, Minnehaha, Turner | 3 hr |
| Aug 2, 6:47 AM CDT | Flash Flood Warning | FSD | Bon Homme, Charles Mix, Douglas, Hutchinson | 3 hr |
| Aug 3, 2:14 PM CDT | Flash Flood Warning | UNR | Lawrence | 2 hr |
| Aug 3, 8:43 PM CDT | Flash Flood Warning | FSD | Aurora, Jerauld, Sanborn | 3 hr |
| Aug 3, 10:00 PM CDT | Flash Flood Warning | FSD | Lincoln, McCook, Minnehaha, Turner | 2 hr |
| Aug 8, 4:33 PM CDT | Flash Flood Warning | FSD | Bon Homme, Charles Mix, Hutchinson | 3 hr |
| Aug 8, 5:08 PM CDT | Flash Flood Warning | FSD | Clay, Hutchinson, Turner, Yankton | 4 hr |
| Aug 10, 4:25 AM CDT | Flash Flood Warning | FSD | Lincoln, Minnehaha | 2 hr |
| Aug 30, 10:33 PM CDT | Flash Flood Warning | FSD | Aurora, Davison, Sanborn | 3 hr |
| Sep 1, 11:25 PM CDT | Flash Flood Warning | ABR | Hamlin | 6 hr |
| Sep 2, 1:52 AM CDT | Flash Flood Warning | FSD | Brookings | 3 hr |
| Sep 2, 2:35 AM CDT | Flash Flood Warning | FSD | Brookings | 3 hr |
| Sep 2, 2:42 AM CDT | Flash Flood Warning | ABR | Deuel | 6 hr |
| Sep 15, 5:20 PM CDT | Flash Flood Warning | ABR | Codington, Deuel, Hamlin | 6 hr |
| Sep 22, 7:31 PM CDT | Flash Flood Warning | FSD | Brookings | 6 hr |
| Sep 22, 8:04 PM CDT | Flash Flood Warning | FSD | Lake, Moody | 6 hr |
| Sep 22, 10:43 PM CDT | Flash Flood Warning | FSD | Clay, Union, Yankton | 6 hr |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Lincoln County13
- Minnehaha County12
- Sanborn County9
- Union County9
- Aurora County8
- Davison County8
- Turner County8
- Charles Mix County7
- Clay County7
- Douglas County6
- Hutchinson County6
- Yankton County6
- Brookings County6
- Jerauld County5
- Bon Homme County5
- Hand County5
- Hyde County5
- Pennington County4
- Brule County4
- Hanson County4
- Lake County4
- Moody County4
- Buffalo County4
- Deuel County4
- Hamlin County4
- Faulk County3
- McCook County3
- Miner County3
- Ziebach County3
- Clark County3
- Codington County3
- Edmunds County2
- McPherson County2
- Spink County2
- Potter County2
- Gregory County2
- Lawrence County2
- Dewey County2
- Lyman County2
- Sully County2
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20092011
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.