Alert archive / South Dakota / Davison County

Weather alerts in Davison County, South Dakota, 2020

111 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Davison County and its neighbors

Each county as a circle sized by its count in 2020. Tap one for its archive.

Alerts
111
Warnings
36
Watches
17
Advisories
34
Busiest month
June34 alerts
Busiest day
June 9, 202016 alerts

Over time

By month

Warning verification

How often warnings here had a storm report inside them, and how much warning the reports had.

0 of 2 tornado warnings covering Davison County in 2020 had a tornado report inside them.

Davison County, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings20100%0
Severe thunderstorm warnings211338%1486%19 min
Flash flood warnings220%0

Each office's whole area, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Sioux Falls, SD: tornado warnings18289%450%17 min
NWS Sioux Falls, SD: severe thunderstorm warnings20215125%29888%21 min
NWS Sioux Falls, SD: flash flood warnings13931%1771%67 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.

IssuedProductOfficeLasted
Jan 4, 2:10 PM CSTWind AdvisoryFSD25 hr
Jan 16, 3:46 AM CSTWinter Weather AdvisoryFSD8 hr
Jan 16, 11:34 AM CSTWinter Storm WarningFSD36 hr
Jan 17, 3:57 AM CSTBlizzard WarningFSD38 hr
Jan 17, 6:32 AM CSTMesoscale DiscussionSPC5 hr
Jan 18, 3:43 AM CSTWind Chill AdvisoryFSD32 hr
Jan 18, 11:38 AM CSTWinter Weather AdvisoryFSD6 hr
Jan 29, 5:56 PM CSTDense Fog AdvisoryFSD42 hr
Feb 11, 3:32 PM CSTWinter Weather AdvisoryFSD26 hr
Feb 11, 8:35 PM CSTWind Chill AdvisoryFSD36 hr
Feb 27, 9:12 AM CSTRiver Flood WarningFSD147 days
Mar 1, 7:12 PM CSTRiver Flood WarningFSD9 days
Mar 4, 2:33 PM CSTWind AdvisoryFSD27 hr
Mar 18, 3:00 PM CDTWinter Weather AdvisoryFSD37 hr
Mar 27, 3:44 AM CDTFlood WatchFSD42 hr
Mar 27, 3:41 PM CDTWind AdvisoryFSD36 hr
Apr 1, 4:42 AM CDTWinter Weather AdvisoryFSD53 hr
Apr 8, 3:20 AM CDTWind AdvisoryFSD16 hr
Apr 11, 3:08 AM CDTWinter Weather AdvisoryFSD43 hr
Apr 20, 3:44 AM CDTWind AdvisoryFSD15 hr
Apr 28, 5:31 PM CDTMesoscale DiscussionSPC119 min
May 7, 3:49 AM CDTFreeze WarningFSD29 hr
May 9, 3:38 AM CDTFreeze WarningFSD29 hr
May 9, 3:54 AM CDTWind AdvisoryFSD17 hr
May 10, 4:20 AM CDTFreeze WarningFSD28 hr
May 23, 11:58 PM CDTSevere Thunderstorm WatchSPC6 hr
Jun 4, 7:42 PM CDTSevere Thunderstorm WatchSPC6 hr
Jun 4, 9:36 PM CDTMesoscale DiscussionSPC84 min
Jun 6, 8:29 PM CDTMesoscale DiscussionSPC91 min
Jun 6, 9:11 PM CDTSevere Thunderstorm WatchSPC6 hr
Jun 7, 2:04 PM CDTMesoscale DiscussionSPC116 min
Jun 8, 10:31 AM CDTRiver Flood WarningFSD5 days
Jun 8, 3:16 PM CDTMesoscale DiscussionSPC2 hr
Jun 8, 5:56 PM CDTSevere Thunderstorm WatchSPC9 hr
Jun 8, 6:08 PM CDTFlash Flood WatchFSD13 hr
Jun 8, 9:13 PM CDTMesoscale DiscussionSPC2 hr
Jun 8, 9:30 PM CDTSevere Thunderstorm WarningFSD30 min
Jun 8, 9:52 PM CDTTornado WarningFSD23 min
Jun 8, 10:08 PM CDTTornado WarningFSD52 min
Jun 8, 10:37 PM CDTSevere Thunderstorm WarningFSD38 min
Jun 8, 11:11 PM CDTSevere Thunderstorm WarningFSD34 min
Jun 9, 12:38 AM CDTSevere Thunderstorm WarningFSD37 min
Jun 9, 12:46 AM CDTMesoscale DiscussionSPC89 min
Jun 9, 3:50 AM CDTWind AdvisoryFSD27 hr
Jun 9, 5:36 AM CDTSevere Thunderstorm WarningFSD24 min
Jun 9, 5:47 AM CDTSevere Thunderstorm WarningFSD28 min
Jun 9, 5:56 AM CDTSevere Thunderstorm WarningFSD34 min
Jun 9, 6:10 AM CDTSevere Thunderstorm WarningFSD35 min
Jun 9, 6:23 AM CDTSevere Thunderstorm WarningFSD37 min
Jun 9, 11:56 AM CDTFlash Flood WarningFSD4 hr
Jun 9, 3:58 PM CDTAreal Flood WarningFSD21 hr
Jun 16, 3:31 AM CDTWind AdvisoryFSD17 hr
Jun 20, 3:20 PM CDTSevere Thunderstorm WatchSPC7 hr
Jun 20, 7:28 PM CDTMesoscale DiscussionSPC2 hr
Jun 25, 1:16 PM CDTMesoscale DiscussionSPC119 min
Jun 25, 3:30 PM CDTSevere Thunderstorm WatchSPC8 hr
Jun 25, 5:42 PM CDTSevere Thunderstorm WarningFSD48 min
Jun 28, 3:22 PM CDTHeat AdvisoryFSD26 hr
Jun 30, 1:42 PM CDTFlash Flood WatchFSD11 hr
Jun 30, 6:34 PM CDTSevere Thunderstorm WatchSPC6 hr
Jun 30, 9:26 PM CDTMesoscale DiscussionSPC2 hr
Jul 3, 12:34 AM CDTSevere Thunderstorm WarningFSD41 min
Jul 3, 12:47 AM CDTSevere Thunderstorm WarningFSD43 min
Jul 3, 1:08 AM CDTSevere Thunderstorm WarningFSD52 min
Jul 3, 1:16 AM CDTMesoscale DiscussionSPC2 hr
Jul 5, 8:33 PM CDTMesoscale DiscussionSPC117 min
Jul 6, 1:57 PM CDTMesoscale DiscussionSPC2 hr
Jul 6, 10:47 PM CDTSevere Thunderstorm WatchSPC4 hr
Jul 6, 11:45 PM CDTFlash Flood WatchFSD5 hr
Jul 7, 12:26 AM CDTFlash Flood WarningFSD5 hr
Jul 7, 1:06 AM CDTSevere Thunderstorm WarningFSD39 min
Jul 8, 3:39 PM CDTMesoscale DiscussionSPC3 hr
Jul 8, 5:10 PM CDTSevere Thunderstorm WatchSPC7 hr
Jul 16, 2:34 PM CDTHeat AdvisoryFSD29 hr
Jul 17, 2:36 PM CDTHeat AdvisoryFSD25 hr
Jul 20, 12:16 PM CDTMesoscale DiscussionSPC119 min
Jul 23, 3:03 AM CDTHeat AdvisoryFSD66 hr
Jul 24, 10:09 PM CDTSevere Thunderstorm WarningFSD51 min
Jul 24, 10:45 PM CDTSevere Thunderstorm WarningFSD45 min
Aug 8, 10:10 PM CDTSevere Thunderstorm WatchSPC6 hr
Aug 8, 11:51 PM CDTMesoscale DiscussionSPC84 min
Aug 9, 12:19 AM CDTSevere Thunderstorm WarningFSD41 min
Aug 9, 12:47 AM CDTSevere Thunderstorm WarningFSD43 min
Aug 9, 1:46 AM CDTMesoscale DiscussionSPC59 min
Aug 10, 2:47 AM CDTSevere Thunderstorm WarningFSD43 min
Aug 10, 3:19 AM CDTMesoscale DiscussionSPC116 min
Aug 10, 3:23 AM CDTSevere Thunderstorm WarningFSD34 min
Aug 24, 3:54 AM CDTHeat AdvisoryFSD17 hr
Aug 25, 3:25 AM CDTHeat AdvisoryFSD17 hr
Aug 27, 10:20 PM CDTSevere Thunderstorm WatchSPC5 hr
Aug 27, 11:30 PM CDTMesoscale DiscussionSPC2 hr
Aug 28, 1:05 AM CDTSevere Thunderstorm WarningFSD25 min
Aug 30, 3:22 PM CDTMesoscale DiscussionSPC113 min
Aug 30, 4:55 PM CDTSevere Thunderstorm WatchSPC5 hr
Aug 30, 8:00 PM CDTMesoscale DiscussionSPC2 hr
Sep 9, 3:36 AM CDTFrost AdvisoryFSD29 hr
Sep 29, 2:36 PM CDTWind AdvisoryFSD29 hr
Oct 1, 3:12 AM CDTFrost AdvisoryFSD29 hr
Oct 13, 2:40 PM CDTWind AdvisoryFSD31 hr
Oct 21, 2:52 PM CDTWinter Weather AdvisoryFSD28 hr
Oct 23, 3:10 PM CDTWinter Weather AdvisoryFSD58 hr
Oct 30, 3:06 PM CDTWind AdvisoryFSD29 hr
Nov 7, 2:33 PM CSTWind AdvisoryFSD27 hr
Nov 10, 9:42 AM CSTMesoscale DiscussionSPC6 hr
Dec 21, 3:16 AM CSTWind AdvisoryFSD13 hr
Dec 22, 11:50 AM CSTWinter Weather AdvisoryFSD15 hr
Dec 22, 2:38 PM CSTBlizzard WarningFSD36 hr
Dec 23, 7:42 AM CSTMesoscale DiscussionSPC5 hr
Dec 27, 7:00 PM CSTWinter Storm WatchFSD8 hr
Dec 28, 3:01 AM CSTWinter Weather AdvisoryFSD42 hr
Dec 29, 7:18 AM CSTWinter Storm WarningFSD11 hr

By product

Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.

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.