Alert archive / South Dakota / Brown County

Weather alerts in Brown County, South Dakota, 2020

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

Brown County and its neighbors

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

Alerts: 157
Warnings: 46
Watches: 15
Advisories: 51
Busiest month: June41 alerts
Busiest day: July 5, 20208 alerts

Over time

By month

Warning verification

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

1 of 1 tornado warnings covering Brown County in 2020 had a tornado report inside them; 1 of 3 tornado reports fell inside a warning, on average 1 minutes after it went out.

Brown County, 2020

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	1	1	0%	3	33%	1 min
Severe thunderstorm warnings	30	22	27%	39	85%	18 min
Flash flood warnings	1	1	0%	0

Each office's whole area, 2020

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Aberdeen, SD: tornado warnings	11	3	73%	16	19%	6 min
NWS Aberdeen, SD: severe thunderstorm warnings	262	160	39%	356	78%	19 min
NWS Aberdeen, SD: flash flood warnings	4	1	75%	1	100%	205 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	Lasted
Jan 4, 1:29 PM CST	Wind Advisory	ABR	23 hr
Jan 10, 2:25 PM CST	Wind Chill Advisory	ABR	22 hr
Jan 14, 2:26 PM CST	Winter Weather Advisory	ABR	12 hr
Jan 15, 3:54 AM CST	Wind Chill Advisory	ABR	32 hr
Jan 15, 2:34 PM CST	Winter Storm Watch	ABR	37 hr
Jan 16, 1:35 PM CST	Winter Storm Warning	ABR	34 hr
Jan 16, 1:35 PM CST	Winter Weather Advisory	ABR	31 hr
Jan 17, 3:48 AM CST	Blizzard Warning	ABR	38 hr
Jan 18, 3:38 AM CST	Wind Chill Advisory	ABR	32 hr
Jan 18, 10:05 AM CST	Winter Weather Advisory	ABR	6 hr
Jan 24, 3:55 AM CST	Dense Fog Advisory	ABR	31 hr
Jan 26, 1:16 PM CST	Winter Weather Advisory	ABR	11 hr
Jan 28, 8:10 PM CST	Dense Fog Advisory	ABR	16 hr
Jan 29, 3:02 PM CST	Dense Fog Advisory	ABR	21 hr
Jan 30, 12:06 PM CST	Dense Fog Advisory	ABR	21 hr
Feb 8, 3:24 AM CST	Winter Weather Advisory	ABR	26 hr
Feb 11, 2:38 PM CST	Wind Chill Warning	ABR	43 hr
Feb 11, 2:38 PM CST	Wind Chill Advisory	ABR	43 hr
Feb 11, 2:38 PM CST	Winter Weather Advisory	ABR	27 hr
Feb 13, 9:38 AM CST	Wind Chill Advisory	ABR	2 hr
Feb 13, 2:51 PM CST	Wind Chill Advisory	ABR	16 hr
Feb 17, 1:14 AM CST	Dense Fog Advisory	ABR	8 hr
Feb 19, 2:19 PM CST	Wind Chill Advisory	ABR	19 hr
Feb 28, 9:20 PM CST	Dense Fog Advisory	ABR	12 hr
Mar 4, 2:44 PM CST	Wind Advisory	ABR	27 hr
Mar 6, 2:24 AM CST	Dense Fog Advisory	ABR	5 hr
Mar 19, 3:22 AM CDT	Wind Advisory	ABR	21 hr
Mar 23, 2:22 PM CDT	River Flood Warning	ABR	48 hr
Mar 27, 8:56 AM CDT	Dense Fog Advisory	ABR	3 hr
Mar 28, 1:35 PM CDT	River Flood Warning	ABR	18 hr
Apr 1, 4:00 AM CDT	Winter Weather Advisory	ABR	51 hr
Apr 1, 2:44 PM CDT	Winter Storm Warning	ABR	24 hr
Apr 6, 7:45 PM CDT	Severe Thunderstorm Warning	ABR	45 min
Apr 6, 7:53 PM CDT	Mesoscale Discussion	SPC	3 hr
Apr 6, 8:41 PM CDT	Special Weather Statement	ABR	34 min
Apr 6, 9:14 PM CDT	Severe Thunderstorm Warning	ABR	46 min
Apr 8, 3:14 AM CDT	Wind Advisory	ABR	17 hr
Apr 9, 8:44 AM CDT	Snow Squall Warning	ABR	61 min
Apr 20, 3:34 AM CDT	Wind Advisory	ABR	15 hr
May 8, 9:36 PM CDT	Wind Advisory	ABR	23 hr
Jun 2, 7:42 AM CDT	Mesoscale Discussion	SPC	93 min
Jun 2, 8:38 AM CDT	Special Weather Statement	ABR	22 min
Jun 4, 6:27 PM CDT	Special Weather Statement	ABR	48 min
Jun 4, 6:35 PM CDT	Severe Thunderstorm Warning	ABR	40 min
Jun 4, 7:14 PM CDT	Severe Thunderstorm Warning	ABR	46 min
Jun 6, 8:29 PM CDT	Mesoscale Discussion	SPC	91 min
Jun 6, 9:11 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 7, 2:04 PM CDT	Mesoscale Discussion	SPC	116 min
Jun 7, 3:31 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jun 7, 6:00 PM CDT	Mesoscale Discussion	SPC	90 min
Jun 7, 6:46 PM CDT	Severe Thunderstorm Warning	ABR	44 min
Jun 7, 7:55 PM CDT	Severe Thunderstorm Warning	ABR	35 min
Jun 7, 8:21 PM CDT	Severe Thunderstorm Warning	ABR	39 min
Jun 7, 8:34 PM CDT	Tornado Warning	ABR	13 min
Jun 7, 8:52 PM CDT	Severe Thunderstorm Warning	ABR	53 min
Jun 7, 9:18 PM CDT	Mesoscale Discussion	SPC	57 min
Jun 7, 9:34 PM CDT	Severe Thunderstorm Warning	ABR	41 min
Jun 7, 9:58 PM CDT	Severe Thunderstorm Warning	ABR	47 min
Jun 14, 3:21 AM CDT	Wind Advisory	ABR	16 hr
Jun 16, 3:16 AM CDT	Wind Advisory	ABR	18 hr
Jun 17, 5:26 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 17, 6:29 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 17, 6:42 PM CDT	Special Weather Statement	ABR	48 min
Jun 17, 7:16 PM CDT	Severe Thunderstorm Warning	ABR	17 min
Jun 17, 7:45 PM CDT	Special Weather Statement	ABR	45 min
Jun 17, 8:20 PM CDT	Severe Thunderstorm Warning	ABR	40 min
Jun 17, 8:40 PM CDT	Special Weather Statement	ABR	35 min
Jun 17, 9:23 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 17, 11:16 PM CDT	Mesoscale Discussion	SPC	89 min
Jun 20, 1:18 PM CDT	Mesoscale Discussion	SPC	117 min
Jun 20, 3:20 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 20, 3:27 PM CDT	Special Weather Statement	ABR	48 min
Jun 20, 4:28 PM CDT	Special Weather Statement	ABR	47 min
Jun 20, 5:51 PM CDT	Severe Thunderstorm Warning	ABR	24 min
Jun 20, 6:26 PM CDT	Severe Thunderstorm Warning	ABR	27 min
Jun 20, 6:41 PM CDT	Severe Thunderstorm Warning	ABR	49 min
Jun 25, 1:16 PM CDT	Mesoscale Discussion	SPC	119 min
Jun 28, 6:57 AM CDT	Special Weather Statement	ABR	48 min
Jun 28, 3:41 PM CDT	Heat Advisory	ABR	28 hr
Jun 30, 5:25 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 30, 6:04 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 30, 8:38 PM CDT	Mesoscale Discussion	SPC	67 min
Jul 4, 3:53 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 4, 6:05 PM CDT	Severe Thunderstorm Warning	ABR	40 min
Jul 4, 7:04 PM CDT	Severe Thunderstorm Warning	ABR	41 min
Jul 4, 7:38 PM CDT	Mesoscale Discussion	SPC	67 min
Jul 4, 7:48 PM CDT	Severe Thunderstorm Warning	ABR	57 min
Jul 4, 8:44 PM CDT	Severe Thunderstorm Warning	ABR	46 min
Jul 5, 12:34 PM CDT	Flash Flood Watch	ABR	15 hr
Jul 5, 3:32 PM CDT	Mesoscale Discussion	SPC	118 min
Jul 5, 4:41 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 5, 6:29 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 5, 8:33 PM CDT	Mesoscale Discussion	SPC	117 min
Jul 5, 9:14 PM CDT	Special Weather Statement	ABR	46 min
Jul 5, 9:19 PM CDT	Severe Thunderstorm Warning	ABR	41 min
Jul 8, 4:10 AM CDT	Mesoscale Discussion	SPC	2 hr
Jul 16, 2:23 PM CDT	Heat Advisory	ABR	30 hr
Jul 17, 5:39 PM CDT	Severe Thunderstorm Watch PDS	SPC	8 hr
Jul 17, 7:57 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 17, 10:25 PM CDT	Severe Thunderstorm Warning	ABR	50 min
Jul 17, 10:25 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 17, 11:12 PM CDT	Special Weather Statement	ABR	33 min
Jul 17, 11:36 PM CDT	Mesoscale Discussion	SPC	114 min
Jul 20, 12:16 PM CDT	Mesoscale Discussion	SPC	119 min
Jul 20, 5:24 PM CDT	Special Weather Statement	ABR	36 min
Jul 23, 3:03 AM CDT	Heat Advisory	ABR	65 hr
Jul 24, 10:04 PM CDT	Severe Thunderstorm Warning	ABR	41 min
Jul 24, 10:58 PM CDT	Areal Flood Warning	ABR	36 hr
Jul 24, 11:45 PM CDT	Flash Flood Warning	ABR	6 hr
Jul 25, 7:08 AM CDT	River Flood Warning	ABR	4 days
Jul 25, 1:24 PM CDT	River Flood Warning	ABR	4 days
Jul 25, 11:07 PM CDT	Special Weather Statement	ABR	38 min
Jul 25, 11:22 PM CDT	Severe Thunderstorm Warning	ABR	38 min
Jul 26, 12:28 AM CDT	Severe Thunderstorm Warning	ABR	47 min
Jul 26, 10:57 AM CDT	Areal Flood Warning	ABR	24 hr
Jul 26, 9:08 PM CDT	River Flood Warning	ABR	54 hr
Jul 31, 7:53 PM CDT	Severe Thunderstorm Warning	ABR	67 min
Jul 31, 8:21 PM CDT	Severe Thunderstorm Warning	ABR	39 min
Aug 6, 5:01 AM CDT	Dense Fog Advisory	ABR	5 hr
Aug 8, 8:13 AM CDT	Special Weather Statement	ABR	62 min
Aug 8, 8:58 AM CDT	Severe Thunderstorm Warning	ABR	32 min
Aug 8, 10:10 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 9, 5:09 PM CDT	Mesoscale Discussion	SPC	96 min
Aug 12, 12:36 AM CDT	Mesoscale Discussion	SPC	84 min
Aug 12, 2:37 AM CDT	Special Weather Statement	ABR	53 min
Aug 12, 3:29 AM CDT	Special Weather Statement	ABR	61 min
Aug 13, 3:11 AM CDT	Heat Advisory	ABR	16 hr
Aug 13, 10:04 PM CDT	Special Weather Statement	ABR	41 min
Aug 23, 5:10 PM CDT	Mesoscale Discussion	SPC	95 min
Aug 23, 5:13 PM CDT	Severe Thunderstorm Warning	ABR	47 min
Aug 23, 5:57 PM CDT	Severe Thunderstorm Warning	ABR	19 min
Aug 27, 10:20 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Aug 30, 3:22 PM CDT	Mesoscale Discussion	SPC	113 min
Aug 30, 4:55 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Aug 30, 5:35 PM CDT	Special Weather Statement	ABR	40 min
Aug 30, 5:47 PM CDT	Severe Thunderstorm Warning	ABR	31 min
Sep 2, 3:24 AM CDT	Wind Advisory	ABR	24 hr
Sep 8, 3:29 PM CDT	Frost Advisory	ABR	18 hr
Sep 9, 12:52 PM CDT	Frost Advisory	ABR	20 hr
Sep 29, 2:30 PM CDT	Wind Advisory	ABR	30 hr
Oct 1, 3:10 AM CDT	Frost Advisory	ABR	29 hr
Oct 3, 2:21 PM CDT	Frost Advisory	ABR	19 hr
Oct 13, 3:52 PM CDT	Wind Advisory	ABR	27 hr
Oct 19, 3:24 PM CDT	Winter Weather Advisory	ABR	28 hr
Oct 20, 4:13 PM CDT	Winter Storm Watch	ABR	23 hr
Oct 21, 3:08 PM CDT	Winter Storm Warning	ABR	30 hr
Oct 21, 9:56 PM CDT	Mesoscale Discussion	SPC	3 hr
Oct 30, 1:47 PM CDT	Wind Advisory	ABR	30 hr
Nov 7, 1:21 PM CST	Wind Advisory	ABR	29 hr
Nov 9, 8:14 AM CST	Winter Weather Advisory	ABR	2 hr
Dec 21, 5:23 AM CST	Wind Advisory	ABR	9 hr
Dec 21, 2:01 PM CST	High Wind Watch	ABR	25 hr
Dec 22, 2:23 PM CST	Winter Weather Advisory	ABR	24 hr
Dec 22, 2:31 PM CST	High Wind Warning	ABR	24 hr
Dec 23, 2:38 PM CST	Wind Chill Advisory	ABR	21 hr
Dec 26, 6:32 AM CST	Dense Fog Advisory	ABR	3 hr
Dec 28, 3:56 AM CST	Winter Weather Advisory	ABR	44 hr

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	30
Tornado Warning	1
Severe Thunderstorm Watch	11
Mesoscale Discussion	27
Special Weather Statement	18
Flooding
Areal Flood Warning	2
Flash Flood Warning	1
River Flood Warning	5
Flash Flood Watch	1
Winter
Blizzard Warning	1
Snow Squall Warning	1
Winter Storm Warning	3
Winter Storm Watch	2
Winter Weather Advisory	11
Heat
Heat Advisory	4
Cold
Wind Chill Warning	1
Frost Advisory	4
Wind Chill Advisory	8
Wind and dust
High Wind Warning	1
High Wind Watch	1
Wind Advisory	14
Fog and smoke
Dense Fog Advisory	10

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2019 2021

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.