Alert archive / North Dakota / Williams County

Weather alerts in Williams County, North Dakota, 2020

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

Williams County and its neighbors

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

Alerts: 129
Warnings: 28
Watches: 17
Advisories: 47
Busiest month: July35 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.

0 of 1 tornado warnings covering Williams County in 2020 had a tornado report inside them.

Williams County, 2020

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	1	0	100%	0
Severe thunderstorm warnings	10	6	40%	10	80%	29 min
Flash flood warnings	0			0

Each office's whole area, 2020

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Bismarck, ND: tornado warnings	18	4	78%	13	31%	6 min
NWS Bismarck, ND: severe thunderstorm warnings	291	171	41%	339	83%	25 min
NWS Bismarck, ND: flash flood warnings	1	0	100%	0

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 3, 2:50 PM CST	High Wind Watch	BIS	24 hr
Jan 4, 2:45 PM CST	Wind Advisory	BIS	21 hr
Jan 9, 1:29 PM CST	Wind Chill Advisory	BIS	23 hr
Jan 13, 2:51 PM CST	Wind Chill Advisory	BIS	3 days
Jan 14, 6:00 PM CST	Wind Chill Warning	BIS	18 hr
Jan 14, 6:00 PM CST	Wind Chill Advisory	BIS	45 hr
Jan 17, 4:05 AM CST	Wind Chill Advisory	BIS	56 hr
Jan 17, 6:59 PM CST	Wind Chill Warning	BIS	17 hr
Jan 17, 6:59 PM CST	Wind Chill Advisory	BIS	17 hr
Jan 18, 12:04 PM CST	Wind Chill Warning	BIS	3 hr
Jan 19, 2:50 PM CST	Wind Chill Advisory	BIS	19 hr
Jan 23, 6:14 PM CST	Dense Fog Advisory	BIS	21 hr
Jan 24, 6:21 PM CST	Dense Fog Advisory	BIS	11 hr
Jan 28, 9:07 PM CST	Dense Fog Advisory	BIS	15 hr
Jan 29, 7:01 PM CST	Dense Fog Advisory	BIS	17 hr
Feb 1, 1:28 PM CST	Wind Advisory	BIS	21 hr
Feb 12, 3:12 AM CST	Wind Chill Advisory	BIS	33 hr
Feb 18, 2:51 PM CST	Wind Chill Advisory	BIS	19 hr
Feb 29, 2:37 PM CST	Wind Advisory	BIS	27 hr
Mar 1, 7:43 AM CST	High Wind Warning	BIS	4 hr
Mar 1, 7:43 AM CST	Wind Advisory	BIS	10 hr
Mar 2, 9:56 AM CST	River Flood Warning	BIS	17 days
Mar 4, 1:48 PM CST	Wind Advisory	BIS	5 hr
Mar 10, 6:08 AM CDT	Dense Fog Advisory	BIS	6 hr
Mar 31, 2:28 PM CDT	Winter Weather Advisory	BIS	29 hr
Apr 1, 3:48 AM CDT	Winter Storm Warning	BIS	11 hr
Apr 6, 8:38 AM CDT	Dense Fog Advisory	BIS	3 hr
Apr 8, 3:00 AM CDT	Wind Advisory	BIS	17 hr
Apr 19, 5:07 AM CDT	Red Flag Warning	BIS	15 hr
Apr 25, 2:35 PM CDT	Fire Weather Watch	BIS	14 hr
Apr 26, 4:15 AM CDT	Red Flag Warning	BIS	16 hr
Apr 27, 2:34 PM CDT	Wind Advisory	BIS	30 hr
Apr 28, 10:13 AM CDT	High Wind Warning	BIS	11 hr
May 8, 2:14 PM CDT	Wind Advisory	BIS	29 hr
May 18, 9:11 AM CDT	Wind Advisory	BIS	12 hr
May 20, 9:50 AM CDT	Wind Advisory	BIS	11 hr
May 31, 10:01 AM CDT	Wind Advisory	BIS	10 hr
Jun 3, 10:42 AM CDT	River Flood Warning	BIS	15 days
Jun 6, 7:17 AM CDT	Special Weather Statement	BIS	43 min
Jun 6, 8:12 AM CDT	Special Weather Statement	BIS	33 min
Jun 6, 10:05 AM CDT	Wind Advisory	BIS	10 hr
Jun 6, 8:04 PM CDT	Wind Advisory	BIS	87 min
Jun 6, 9:11 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 7, 3:59 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 13, 3:48 AM CDT	Wind Advisory	BIS	18 hr
Jun 14, 2:20 PM CDT	Mesoscale Discussion	SPC	115 min
Jun 14, 3:20 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jun 14, 6:55 PM CDT	Severe Thunderstorm Warning	BIS	65 min
Jun 14, 8:17 PM CDT	Special Weather Statement	BIS	43 min
Jun 29, 2:43 PM CDT	Flash Flood Watch	BIS	31 hr
Jun 29, 3:44 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 29, 4:56 PM CDT	Tornado Watch	SPC	8 hr
Jun 29, 7:43 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 1, 8:10 PM CDT	Special Weather Statement	BIS	50 min
Jul 3, 12:18 PM CDT	Special Weather Statement	BIS	27 min
Jul 3, 1:16 PM CDT	Special Weather Statement	BIS	29 min
Jul 3, 6:30 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 3, 8:22 PM CDT	Mesoscale Discussion	SPC	113 min
Jul 3, 11:00 PM CDT	Severe Thunderstorm Warning	BIS	45 min
Jul 4, 9:46 PM CDT	Mesoscale Discussion	SPC	119 min
Jul 4, 10:42 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Jul 5, 12:05 AM CDT	Severe Thunderstorm Warning	BIS	55 min
Jul 5, 12:16 AM CDT	Special Weather Statement	BIS	14 min
Jul 5, 12:39 AM CDT	Severe Thunderstorm Warning	BIS	66 min
Jul 5, 1:25 AM CDT	Mesoscale Discussion	SPC	2 hr
Jul 5, 1:27 AM CDT	Severe Thunderstorm Warning	BIS	63 min
Jul 5, 5:31 PM CDT	Severe Thunderstorm Warning	BIS	38 min
Jul 7, 7:35 PM CDT	Mesoscale Discussion	SPC	55 min
Jul 7, 7:59 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 7, 8:07 PM CDT	Special Weather Statement	BIS	23 min
Jul 7, 8:43 PM CDT	Severe Thunderstorm Warning	BIS	62 min
Jul 7, 9:44 PM CDT	Severe Thunderstorm Warning	BIS	61 min
Jul 10, 1:26 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 10, 2:08 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 10, 3:43 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 10, 4:16 PM CDT	Special Weather Statement	BIS	44 min
Jul 10, 5:00 PM CDT	Special Weather Statement	BIS	45 min
Jul 10, 5:45 PM CDT	Special Weather Statement	BIS	30 min
Jul 10, 7:45 PM CDT	Special Weather Statement	BIS	45 min
Jul 12, 7:06 PM CDT	Mesoscale Discussion	SPC	114 min
Jul 12, 8:36 PM CDT	Severe Thunderstorm Warning	BIS	25 min
Jul 18, 1:16 PM CDT	Mesoscale Discussion	SPC	119 min
Jul 23, 3:27 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 23, 5:54 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 23, 8:34 PM CDT	Mesoscale Discussion	SPC	116 min
Jul 23, 10:53 PM CDT	Special Weather Statement	BIS	37 min
Jul 23, 11:38 PM CDT	Severe Thunderstorm Warning	BIS	50 min
Jul 29, 8:12 PM CDT	Special Weather Statement	BIS	33 min
Aug 4, 7:39 PM CDT	Tornado Warning Tornado observed	BIS	36 min
Aug 12, 6:16 PM CDT	Mesoscale Discussion	SPC	119 min
Aug 12, 8:19 PM CDT	Special Weather Statement	GGW	41 min
Aug 27, 8:02 PM CDT	Special Weather Statement	BIS	43 min
Aug 27, 8:55 PM CDT	Special Weather Statement	BIS	20 min
Aug 31, 3:56 AM CDT	Fire Weather Watch	BIS	11 hr
Aug 31, 2:29 PM CDT	Red Flag Warning	BIS	30 hr
Sep 1, 5:16 AM CDT	Wind Advisory	BIS	15 hr
Sep 1, 5:56 AM CDT	Fire Weather Watch	BIS	8 hr
Sep 1, 2:23 PM CDT	Red Flag Warning	BIS	32 hr
Sep 1, 2:44 PM CDT	Wind Advisory	BIS	33 hr
Sep 6, 3:00 AM CDT	Freeze Watch	BIS	24 hr
Sep 7, 2:51 AM CDT	Freeze Watch	BIS	36 hr
Sep 7, 2:51 AM CDT	Freeze Warning	BIS	30 hr
Sep 8, 2:32 PM CDT	Freeze Warning	BIS	18 hr
Sep 23, 3:55 AM CDT	Special Weather Statement	BIS	50 min
Sep 25, 3:15 PM CDT	Wind Advisory	BIS	30 hr
Sep 29, 2:20 PM CDT	Wind Advisory	BIS	30 hr
Oct 5, 2:35 PM CDT	Fire Weather Watch	BIS	13 hr
Oct 6, 3:21 AM CDT	Wind Advisory	BIS	12 hr
Oct 6, 3:51 AM CDT	Red Flag Warning	BIS	12 hr
Oct 10, 3:24 AM CDT	Red Flag Warning	BIS	17 hr
Oct 10, 1:15 PM CDT	Wind Advisory	BIS	7 hr
Oct 13, 2:23 PM CDT	Wind Advisory	BIS	29 hr
Oct 16, 2:58 AM CDT	Winter Weather Advisory	BIS	31 hr
Oct 29, 7:37 AM CDT	Special Weather Statement	BIS	38 min
Oct 29, 8:47 AM CDT	Special Weather Statement	BIS	58 min
Oct 30, 4:04 AM CDT	Dense Fog Advisory	BIS	7 hr
Oct 30, 2:13 PM CDT	Wind Advisory	BIS	31 hr
Oct 30, 9:15 PM CDT	Special Weather Statement	BIS	45 min
Nov 7, 2:34 PM CST	Wind Advisory	BIS	33 hr
Nov 7, 8:48 PM CST	Winter Weather Advisory	BIS	24 hr
Nov 7, 9:07 PM CST	Dense Fog Advisory	BIS	17 hr
Nov 13, 2:18 PM CST	Wind Advisory	BIS	31 hr
Nov 17, 2:38 AM CST	Special Weather Statement	BIS	52 min
Nov 18, 2:47 PM CST	Winter Weather Advisory	BIS	27 hr
Dec 11, 2:02 AM CST	Dense Fog Advisory	BIS	12 hr
Dec 20, 4:11 AM CST	Wind Advisory	BIS	16 hr
Dec 21, 3:43 PM CST	High Wind Watch	BIS	24 hr
Dec 22, 4:20 AM CST	High Wind Warning	BIS	32 hr
Dec 23, 6:26 AM CST	Wind Chill Advisory	BIS	6 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	10
Tornado Warning	1
Severe Thunderstorm Watch	7
Tornado Watch	1
Mesoscale Discussion	15
Special Weather Statement	22
Flooding
River Flood Warning	2
Flash Flood Watch	1
Winter
Winter Storm Warning	1
Winter Weather Advisory	4
Cold
Freeze Warning	2
Wind Chill Warning	3
Freeze Watch	2
Wind Chill Advisory	9
Wind and dust
High Wind Warning	3
High Wind Watch	2
Wind Advisory	25
Fire
Red Flag Warning	6
Fire Weather Watch	4
Fog and smoke
Dense Fog Advisory	9

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.