Alert archive / South Dakota / Dewey County

Weather alerts in Dewey County, South Dakota, 2021

146 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Dewey County and its neighbors

Each county as a circle sized by its count in 2021. Tap one for its archive.

Alerts: 146
Warnings: 68
Watches: 24
Advisories: 30
Busiest month: August26 alerts
Busiest day: June 9, 202112 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 1 tornado warnings covering Dewey County in 2021 had a tornado report inside them.

Dewey County, 2021

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	1	0	100%	0
Severe thunderstorm warnings	33	19	42%	19	95%	20 min
Flash flood warnings	2	1	50%	0

Each office's whole area, 2021

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Aberdeen, SD: tornado warnings	21	5	76%	17	35%	19 min
NWS Aberdeen, SD: severe thunderstorm warnings	170	101	41%	220	76%	20 min
NWS Aberdeen, SD: flash flood warnings	4	1	75%	1	100%	104 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, Mountain Time. Each opens its own page with the text, the map, the radar and the sounding.

Issued	Product	Office	Lasted
Jan 6, 7:46 PM MST	Dense Fog Advisory	ABR	13 hr
Jan 8, 8:43 PM MST	Dense Fog Advisory	ABR	14 hr
Jan 12, 10:23 AM MST	High Wind Watch	ABR	27 hr
Jan 13, 12:40 PM MST	Red Flag Warning	ABR	27 hr
Jan 13, 1:37 PM MST	High Wind Warning	ABR	45 hr
Jan 29, 1:39 PM MST	Winter Weather Advisory	ABR	30 hr
Jan 29, 8:33 PM MST	Dense Fog Advisory	ABR	13 hr
Jan 31, 7:55 PM MST	Dense Fog Advisory	ABR	68 hr
Feb 5, 1:59 AM MST	Wind Chill Advisory	ABR	57 hr
Feb 8, 1:40 AM MST	Wind Chill Advisory	ABR	32 hr
Feb 9, 1:41 PM MST	Wind Chill Advisory	ABR	20 hr
Feb 10, 12:29 PM MST	Wind Chill Advisory	ABR	3 days
Feb 11, 12:57 PM MST	Wind Chill Warning	ABR	20 hr
Feb 11, 12:57 PM MST	Wind Chill Advisory	ABR	32 hr
Feb 12, 1:27 PM MST	Wind Chill Warning	ABR	69 hr
Feb 15, 10:30 AM MST	Wind Chill Warning	ABR	22 hr
Feb 21, 12:25 PM MST	Wind Advisory	ABR	29 hr
Feb 23, 2:22 AM MST	Wind Advisory	ABR	14 hr
Mar 6, 1:07 AM MST	Dense Fog Advisory	ABR	8 hr
Mar 14, 5:20 PM MDT	Mesoscale Discussion	SPC	6 hr
Mar 26, 1:41 PM MDT	Fire Weather Watch	ABR	48 hr
Mar 28, 2:53 AM MDT	Red Flag Warning	ABR	16 hr
Mar 28, 1:31 PM MDT	High Wind Warning	ABR	28 hr
Mar 28, 1:31 PM MDT	Wind Advisory	ABR	32 hr
Mar 28, 1:36 PM MDT	Red Flag Warning	ABR	31 hr
Mar 29, 2:00 AM MDT	Fire Weather Watch	ABR	23 hr
Mar 29, 8:04 PM MDT	High Wind Warning	ABR	10 hr
Mar 29, 8:04 PM MDT	Wind Advisory	ABR	21 hr
Mar 30, 1:14 AM MDT	Red Flag Warning	ABR	18 hr
Mar 30, 5:11 PM MDT	Wind Advisory	ABR	3 hr
Mar 31, 2:02 AM MDT	Fire Weather Watch	ABR	12 hr
Mar 31, 1:48 PM MDT	Red Flag Warning	ABR	31 hr
Apr 2, 1:54 AM MDT	Red Flag Warning	ABR	17 hr
Apr 3, 2:15 AM MDT	Red Flag Warning	ABR	17 hr
Apr 4, 2:54 AM MDT	Red Flag Warning	ABR	15 hr
Apr 5, 2:32 AM MDT	Red Flag Warning	ABR	16 hr
Apr 8, 2:17 PM MDT	Wind Advisory	ABR	27 hr
Apr 9, 2:48 AM MDT	Red Flag Warning	ABR	17 hr
Apr 10, 1:43 PM MDT	Wind Advisory	ABR	52 hr
Apr 29, 1:17 AM MDT	Fire Weather Watch	ABR	13 hr
Apr 29, 2:31 PM MDT	Red Flag Warning	ABR	29 hr
May 1, 1:50 AM MDT	Red Flag Warning	ABR	17 hr
May 5, 1:52 PM MDT	Fire Weather Watch	ABR	13 hr
May 23, 1:50 PM MDT	Tornado Watch	SPC	7 hr
May 23, 5:25 PM MDT	Mesoscale Discussion	SPC	95 min
May 23, 6:59 PM MDT	Severe Thunderstorm Warning	ABR	46 min
May 23, 7:22 PM MDT	Mesoscale Discussion	SPC	53 min
May 24, 1:59 PM MDT	Wind Advisory	ABR	28 hr
Jun 8, 4:18 PM MDT	Special Weather Statement	ABR	27 min
Jun 8, 4:46 PM MDT	Severe Thunderstorm Warning	ABR	44 min
Jun 8, 5:11 PM MDT	Flash Flood Watch	ABR	4 hr
Jun 8, 5:23 PM MDT	Severe Thunderstorm Warning	ABR	52 min
Jun 8, 6:17 PM MDT	Severe Thunderstorm Warning	ABR	43 min
Jun 8, 6:44 PM MDT	Flash Flood Warning	ABR	3 hr
Jun 8, 7:11 PM MDT	Severe Thunderstorm Warning	ABR	49 min
Jun 8, 7:21 PM MDT	Tornado Warning Tornado observed	ABR	24 min
Jun 8, 7:25 PM MDT	Severe Thunderstorm Warning	ABR	50 min
Jun 8, 8:28 PM MDT	Severe Thunderstorm Warning	ABR	47 min
Jun 8, 9:12 PM MDT	Severe Thunderstorm Warning	ABR	36 min
Jun 8, 9:33 PM MDT	Flash Flood Warning Considerable damage threat	ABR	8 hr
Jun 8, 10:41 PM MDT	Mesoscale Discussion	SPC	94 min
Jun 8, 10:54 PM MDT	Severe Thunderstorm Warning	ABR	66 min
Jun 8, 11:58 PM MDT	Severe Thunderstorm Warning	ABR	37 min
Jun 9, 12:03 AM MDT	Special Weather Statement	ABR	57 min
Jun 10, 2:53 AM MDT	Heat Advisory	ABR	16 hr
Jun 10, 7:28 PM MDT	Mesoscale Discussion	SPC	92 min
Jun 10, 8:08 PM MDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 10, 10:07 PM MDT	Mesoscale Discussion	SPC	83 min
Jun 10, 10:50 PM MDT	Mesoscale Discussion	SPC	85 min
Jun 11, 12:02 AM MDT	Severe Thunderstorm Warning	ABR	43 min
Jun 11, 12:15 AM MDT	Severe Thunderstorm Warning	ABR	45 min
Jun 13, 1:04 PM MDT	Special Weather Statement	ABR	26 min
Jul 1, 1:17 PM MDT	Fire Weather Watch	ABR	16 hr
Jul 2, 5:06 AM MDT	Red Flag Warning	ABR	15 hr
Jul 3, 1:57 AM MDT	Red Flag Warning	ABR	15 hr
Jul 3, 2:34 PM MDT	Mesoscale Discussion	SPC	116 min
Jul 3, 4:42 PM MDT	Special Weather Statement	ABR	33 min
Jul 3, 5:35 PM MDT	Severe Thunderstorm Warning	ABR	40 min
Jul 3, 6:14 PM MDT	Severe Thunderstorm Warning	ABR	31 min
Jul 3, 6:34 PM MDT	Severe Thunderstorm Warning	ABR	18 min
Jul 8, 7:54 PM MDT	Mesoscale Discussion	SPC	2 hr
Jul 8, 8:33 PM MDT	Severe Thunderstorm Watch	SPC	5 hr
Jul 8, 8:35 PM MDT	Severe Thunderstorm Warning	ABR	26 min
Jul 8, 10:22 PM MDT	Severe Thunderstorm Warning	ABR	53 min
Jul 9, 1:41 AM MDT	Mesoscale Discussion	SPC	34 min
Jul 9, 1:46 AM MDT	Special Weather Statement	ABR	44 min
Jul 9, 3:17 AM MDT	Severe Thunderstorm Warning	ABR	27 min
Jul 22, 5:44 PM MDT	Severe Thunderstorm Warning	ABR	61 min
Jul 22, 6:45 PM MDT	Severe Thunderstorm Warning	ABR	60 min
Jul 23, 4:04 PM MDT	Mesoscale Discussion	SPC	3 hr
Jul 23, 6:02 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 26, 2:41 AM MDT	Heat Advisory	ABR	15 hr
Jul 26, 2:41 AM MDT	Heat Advisory	ABR	41 hr
Jul 27, 2:42 AM MDT	Heat Advisory	ABR	39 hr
Aug 9, 1:43 PM MDT	Fire Weather Watch	ABR	13 hr
Aug 10, 2:28 AM MDT	Red Flag Warning	ABR	17 hr
Aug 14, 5:47 PM MDT	Severe Thunderstorm Warning	ABR	43 min
Aug 14, 6:29 PM MDT	Severe Thunderstorm Warning	ABR	46 min
Aug 14, 7:15 PM MDT	Severe Thunderstorm Warning	ABR	60 min
Aug 14, 7:48 PM MDT	Severe Thunderstorm Warning	ABR	42 min
Aug 14, 8:28 PM MDT	Special Weather Statement	ABR	32 min
Aug 16, 1:21 PM MDT	Fire Weather Watch	ABR	12 hr
Aug 17, 1:39 AM MDT	Red Flag Warning	ABR	17 hr
Aug 19, 6:29 PM MDT	Special Weather Statement	ABR	61 min
Aug 23, 6:12 PM MDT	Severe Thunderstorm Warning	ABR	48 min
Aug 23, 6:38 PM MDT	Mesoscale Discussion	SPC	2 hr
Aug 23, 8:13 PM MDT	Severe Thunderstorm Warning	ABR	47 min
Aug 23, 8:37 PM MDT	Mesoscale Discussion	SPC	113 min
Aug 23, 9:01 PM MDT	Severe Thunderstorm Warning	ABR	59 min
Aug 23, 9:11 PM MDT	Severe Thunderstorm Watch	SPC	5 hr
Aug 23, 9:17 PM MDT	Severe Thunderstorm Warning	ABR	43 min
Aug 23, 9:56 PM MDT	Severe Thunderstorm Warning	ABR	64 min
Aug 26, 1:35 AM MDT	Mesoscale Discussion	SPC	2 hr
Aug 26, 4:37 AM MDT	Special Weather Statement	ABR	53 min
Aug 28, 12:14 AM MDT	Severe Thunderstorm Warning	ABR	31 min
Aug 28, 1:05 AM MDT	Severe Thunderstorm Warning	ABR	40 min
Aug 28, 1:32 AM MDT	Severe Thunderstorm Watch	SPC	5 hr
Aug 28, 3:51 AM MDT	Severe Thunderstorm Warning	ABR	39 min
Aug 28, 4:29 AM MDT	Special Weather Statement	ABR	16 min
Aug 30, 3:03 PM MDT	Severe Thunderstorm Watch	SPC	6 hr
Sep 1, 4:39 PM MDT	Mesoscale Discussion	SPC	2 hr
Sep 5, 2:36 AM MDT	Fire Weather Watch	ABR	11 hr
Sep 5, 1:51 PM MDT	Red Flag Warning	ABR	28 hr
Sep 18, 8:26 AM MDT	Red Flag Warning	ABR	11 hr
Sep 19, 9:09 PM MDT	Severe Thunderstorm Warning	ABR	51 min
Sep 23, 2:00 PM MDT	Fire Weather Watch	ABR	13 hr
Sep 24, 2:59 AM MDT	Red Flag Warning	ABR	15 hr
Oct 6, 2:40 AM MDT	Red Flag Warning	ABR	16 hr
Oct 12, 2:55 PM MDT	Wind Advisory	ABR	30 hr
Oct 15, 10:38 AM MDT	Frost Advisory	ABR	22 hr
Nov 10, 8:49 AM MST	High Wind Watch	ABR	5 hr
Nov 10, 1:45 PM MST	High Wind Warning	ABR	39 hr
Nov 12, 2:02 AM MST	Wind Advisory	ABR	9 hr
Nov 12, 1:33 PM MST	High Wind Watch	ABR	13 hr
Nov 13, 2:26 AM MST	High Wind Warning	ABR	20 hr
Nov 15, 2:40 AM MST	High Wind Watch	ABR	11 hr
Nov 15, 1:47 PM MST	High Wind Warning	ABR	51 hr
Nov 16, 2:09 AM MST	Red Flag Warning	ABR	16 hr
Dec 4, 2:11 AM MST	High Wind Watch	ABR	12 hr
Dec 4, 2:01 PM MST	High Wind Warning	ABR	27 hr
Dec 14, 2:37 AM MST	High Wind Watch	ABR	11 hr
Dec 14, 2:54 AM MST	Winter Weather Advisory	ABR	50 hr
Dec 14, 1:20 PM MST	High Wind Warning	ABR	36 hr
Dec 26, 1:12 AM MST	Winter Weather Advisory	ABR	37 hr
Dec 27, 2:05 PM MST	Wind Chill Advisory	ABR	18 hr
Dec 30, 1:36 PM MST	Wind Chill Advisory	ABR	27 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	33
Tornado Warning	1
Severe Thunderstorm Watch	6
Tornado Watch	1
Mesoscale Discussion	15
Special Weather Statement	9
Flooding
Flash Flood Warning	2
Flash Flood Watch	1
Winter
Winter Weather Advisory	3
Heat
Heat Advisory	4
Cold
Wind Chill Warning	3
Frost Advisory	1
Wind Chill Advisory	7
Wind and dust
High Wind Warning	8
High Wind Watch	6
Wind Advisory	10
Fire
Red Flag Warning	21
Fire Weather Watch	10
Fog and smoke
Dense Fog Advisory	5

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2020 2022

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.