Alert archive / South Dakota / Flash Flood Warnings
Flash Flood Warnings in South Dakota, 2008
40 flash flood warnings in 2008. 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 2008. Tap one for its archive.
- Flash Flood Warnings
- 40
- Busiest month
- June19 flash flood warnings
- Busiest day
- June 5, 200810 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.
19 of 40 flash flood warnings covering South Dakota in 2008 had a flash flood report inside them; 36 of 43 flash flood reports fell inside a warning, on average 81 minutes after it went out.
South Dakota, 2008
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Flash flood warnings | 40 | 19 | 53% | 43 | 84% | 81 min |
Each office's whole area, 2008
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Aberdeen, SD: flash flood warnings | 9 | 4 | 56% | 6 | 67% | 41 min |
| NWS Sioux Falls, SD: flash flood warnings | 28 | 20 | 29% | 44 | 89% | 88 min |
| NWS Rapid City, SD: flash flood warnings | 13 | 1 | 92% | 2 | 50% | 93 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 |
|---|---|---|---|---|
| May 29, 6:21 PM CDT | Flash Flood Warning | FSD | Bon Homme, Yankton | 114 min |
| Jun 2, 10:10 PM CDT | Flash Flood Warning | ABR | Hughes, Stanley | 7 hr |
| Jun 3, 2:51 AM CDT | Flash Flood Warning | FSD | Lincoln, Minnehaha | 116 min |
| Jun 4, 3:41 PM CDT | Flash Flood Warning | FSD | Bon Homme, Yankton | 2 hr |
| Jun 4, 4:25 PM CDT | Flash Flood Warning | FSD | Yankton | 2 hr |
| Jun 4, 5:27 PM CDT | Flash Flood Warning | UNR | Meade, Pennington | 2 hr |
| Jun 5, 3:25 AM CDT | Flash Flood Warning | UNR | Pennington | 6 hr |
| Jun 5, 11:44 AM CDT | Flash Flood Warning | FSD | Bon Homme, Davison, Hanson, Hutchinson, McCook, Turner and 1 more | 5 hr |
| Jun 5, 12:18 PM CDT | Flash Flood Warning | FSD | Clay, Lincoln, McCook, Minnehaha, Turner, Union and 1 more | 6 hr |
| Jun 5, 3:05 PM CDT | Flash Flood Warning | UNR | Tripp | 3 hr |
| Jun 5, 3:16 PM CDT | Flash Flood Warning | FSD | Minnehaha, Moody | 3 hr |
| Jun 5, 3:40 PM CDT | Flash Flood Warning | FSD | Bon Homme, Charles Mix, Douglas, Gregory, Hutchinson | 4 hr |
| Jun 5, 4:15 PM CDT | Flash Flood Warning | FSD | Brule, Jerauld | 3 hr |
| Jun 5, 5:41 PM CDT | Flash Flood Warning | FSD | Aurora, Davison, Jerauld, Sanborn | 119 min |
| Jun 5, 5:54 PM CDT | Flash Flood Warning | FSD | Hanson, Hutchinson, McCook, Miner, Sanborn | 105 min |
| Jun 5, 6:49 PM CDT | Flash Flood Warning | FSD | Bon Homme, Yankton | 50 min |
| Jun 6, 8:49 PM CDT | Flash Flood Warning | UNR | Haakon, Ziebach | 4 hr |
| Jun 11, 9:35 AM CDT | Flash Flood Warning | ABR | Grant, Roberts | 6 hr |
| Jun 19, 3:40 PM CDT | Flash Flood Warning | FSD | Aurora, Brule, Jerauld | 69 min |
| Jun 26, 6:50 AM CDT | Flash Flood Warning | FSD | Union | 2 hr |
| Jul 6, 5:50 PM CDT | Flash Flood Warning | FSD | Aurora, Davison, Hanson | 3 hr |
| Jul 6, 10:27 PM CDT | Flash Flood Warning | UNR | Lawrence, Pennington | 3 hr |
| Jul 6, 11:24 PM CDT | Flash Flood Warning | UNR | Lawrence, Pennington | 5 hr |
| Jul 10, 1:05 AM CDT | Flash Flood Warning | FSD | Gregory | 115 min |
| Jul 18, 6:00 AM CDT | Flash Flood Warning | UNR | Fall River | 3 hr |
| Jul 19, 12:08 AM CDT | Flash Flood Warning | ABR | Dewey | 6 hr |
| Jul 21, 12:16 AM CDT | Flash Flood Warning | FSD | Clay, Union | 3 hr |
| Jul 22, 4:58 PM CDT | Flash Flood Warning | UNR | Fall River | 6 hr |
| Jul 22, 5:38 PM CDT | Flash Flood Warning | UNR | Fall River | 6 hr |
| Jul 23, 6:55 PM CDT | Flash Flood Warning | ABR | Dewey | 2 hr |
| Jul 24, 3:32 AM CDT | Flash Flood Warning | FSD | Hutchinson | 2 hr |
| Aug 6, 12:55 AM CDT | Flash Flood Warning | UNR | Butte, Lawrence | 3 hr |
| Aug 10, 2:41 PM CDT | Flash Flood Warning | UNR | Custer | 4 hr |
| Aug 11, 4:25 PM CDT | Flash Flood Warning | ABR | Buffalo, Hand, Hughes, Hyde, Lyman | 2 hr |
| Aug 11, 4:47 PM CDT | Flash Flood Warning | ABR | Edmunds, Faulk | 114 min |
| Aug 11, 5:08 PM CDT | Flash Flood Warning | ABR | Brown | 108 min |
| Aug 11, 5:58 PM CDT | Flash Flood Warning | ABR | Faulk, Spink | 71 min |
| Aug 11, 7:29 PM CDT | Flash Flood Warning | FSD | Beadle, Kingsbury | 2 hr |
| Aug 13, 5:12 PM CDT | Flash Flood Warning | FSD | Gregory | 2 hr |
| Aug 13, 5:57 PM CDT | Flash Flood Warning | UNR | Tripp | 4 hr |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Yankton County6
- Bon Homme County5
- Pennington County4
- Hutchinson County4
- Minnehaha County3
- Davison County3
- Hanson County3
- McCook County3
- Union County3
- Gregory County3
- Jerauld County3
- Aurora County3
- Lawrence County3
- Fall River County3
- Hughes County2
- Lincoln County2
- Turner County2
- Clay County2
- Tripp County2
- Brule County2
- Sanborn County2
- Dewey County2
- Faulk County2
- Stanley County1
- Meade County1
- Moody County1
- Charles Mix County1
- Douglas County1
- Miner County1
- Haakon County1
- Ziebach County1
- Grant County1
- Roberts County1
- Butte County1
- Custer County1
- Buffalo County1
- Hand County1
- Hyde County1
- Lyman County1
- Edmunds County1
4 more counties
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20072009
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.