Alert archive / North Dakota / Williams County

Weather alerts in Williams County, North Dakota, 2015

112 weather alerts in 2015, 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 2015. Tap one for its archive.

Alerts: 112
Warnings: 28
Watches: 17
Advisories: 46
Busiest month: July24 alerts
Busiest day: July 4, 20156 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 2015 had a tornado report inside them; 0 of 2 tornado reports fell inside a warning.

Williams County, 2015

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	1	0	100%	2	0%
Severe thunderstorm warnings	9	8	11%	7	71%	24 min
Flash flood warnings	2	1	50%	1	100%	25 min

Each office's whole area, 2015

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Bismarck, ND: tornado warnings	15	1	93%	7	14%	4 min
NWS Bismarck, ND: severe thunderstorm warnings	183	122	33%	264	77%	26 min
NWS Bismarck, ND: flash flood warnings	4	2	50%	2	100%	26 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 1, 3:55 AM CST	Winter Storm Watch	BIS	11 hr
Jan 1, 3:10 PM CST	Winter Weather Advisory	BIS	39 hr
Jan 3, 6:30 AM CST	Wind Chill Advisory	BIS	54 hr
Jan 5, 3:42 PM CST	Wind Chill Advisory	BIS	32 hr
Jan 6, 3:24 AM CST	Wind Chill Warning	BIS	33 hr
Jan 7, 3:55 PM CST	Winter Weather Advisory	BIS	26 hr
Jan 8, 2:41 PM CST	Wind Chill Advisory	BIS	21 hr
Jan 9, 2:56 PM CST	Wind Chill Advisory	BIS	19 hr
Jan 11, 3:09 PM CST	Wind Chill Advisory	BIS	19 hr
Feb 3, 9:37 PM CST	Wind Chill Advisory	BIS	12 hr
Feb 5, 3:26 PM CST	Freezing Rain Advisory	BIS	12 hr
Feb 7, 3:12 PM CST	Freezing Rain Advisory	BIS	23 hr
Feb 8, 2:53 PM CST	Dense Fog Advisory	BIS	31 hr
Feb 9, 3:38 AM CST	Freezing Rain Advisory	BIS	29 hr
Feb 9, 10:48 PM CST	Mesoscale Discussion	SPC	3 hr
Feb 13, 3:53 PM CST	Wind Chill Advisory	BIS	24 hr
Feb 14, 3:49 AM CST	Winter Weather Advisory	BIS	30 hr
Feb 16, 3:24 PM CST	Wind Chill Advisory	BIS	45 hr
Feb 20, 5:50 PM CST	Wind Chill Advisory	BIS	60 hr
Feb 25, 3:34 AM CST	Wind Chill Advisory	BIS	32 hr
Feb 26, 2:59 PM CST	Wind Chill Advisory	BIS	19 hr
Mar 2, 2:25 PM CST	Wind Advisory	BIS	28 hr
Mar 3, 2:56 PM CST	Wind Chill Advisory	BIS	21 hr
Mar 4, 2:43 PM CST	Wind Chill Advisory	BIS	18 hr
Mar 24, 2:39 AM CDT	Winter Weather Advisory	BIS	24 hr
Mar 28, 3:59 AM CDT	Wind Advisory	BIS	33 hr
Mar 31, 3:56 AM CDT	Fire Weather Watch	BIS	11 hr
Mar 31, 3:25 PM CDT	Red Flag Warning	BIS	30 hr
Mar 31, 3:46 PM CDT	Wind Advisory	BIS	28 hr
Apr 2, 6:35 AM CDT	Wind Advisory	BIS	12 hr
Apr 11, 4:13 AM CDT	Red Flag Warning	BIS	15 hr
Apr 11, 3:47 PM CDT	Fire Weather Watch	BIS	12 hr
Apr 13, 3:59 AM CDT	Fire Weather Watch	BIS	17 hr
Apr 13, 8:58 PM CDT	Red Flag Warning	BIS	25 hr
Apr 19, 2:33 PM CDT	Red Flag Warning	BIS	31 hr
Apr 30, 3:28 PM CDT	Fire Weather Watch	BIS	12 hr
May 1, 3:21 AM CDT	Red Flag Warning	BIS	16 hr
May 1, 2:51 PM CDT	Fire Weather Watch	BIS	12 hr
May 2, 3:10 AM CDT	Red Flag Warning	BIS	17 hr
May 3, 6:56 PM CDT	Frost Advisory	BIS	14 hr
May 7, 2:58 PM CDT	Frost Advisory	BIS	17 hr
May 8, 3:40 PM CDT	Frost Advisory	BIS	17 hr
May 17, 2:54 PM CDT	Freeze Warning	BIS	19 hr
May 18, 4:00 AM CDT	Freeze Warning	BIS	29 hr
May 19, 3:01 PM CDT	Frost Advisory	BIS	18 hr
Jun 1, 3:41 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 3, 11:05 AM CDT	River Flood Warning	BIS	10 days
Jun 6, 12:15 AM CDT	Flash Flood Warning	BIS	6 hr
Jun 6, 6:50 PM CDT	Special Weather Statement	BIS	25 min
Jun 9, 12:21 PM CDT	River Flood Warning	BIS	12 days
Jun 19, 1:53 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 19, 3:01 PM CDT	Severe Thunderstorm Watch	SPC	9 hr
Jun 19, 4:15 PM CDT	Special Weather Statement	BIS	60 min
Jun 19, 5:11 PM CDT	Severe Thunderstorm Warning	BIS	64 min
Jun 19, 5:48 PM CDT	Mesoscale Discussion	SPC	57 min
Jun 20, 4:30 AM CDT	Dense Fog Advisory	BIS	5 hr
Jun 21, 2:28 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 21, 2:51 PM CDT	Severe Thunderstorm Warning	BIS	54 min
Jun 21, 3:23 PM CDT	Tornado Watch	SPC	8 hr
Jun 21, 5:24 PM CDT	Mesoscale Discussion	SPC	66 min
Jun 23, 2:05 PM CDT	Mesoscale Discussion	SPC	55 min
Jun 25, 9:17 PM CDT	Flash Flood Warning	BIS	3 hr
Jun 30, 5:29 PM CDT	Tornado Watch	SPC	7 hr
Jun 30, 6:49 PM CDT	Special Weather Statement	BIS	26 min
Jul 1, 3:07 AM CDT	Dense Fog Advisory	BIS	7 hr
Jul 4, 1:43 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 4, 2:47 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 4, 3:09 PM CDT	Severe Thunderstorm Warning	BIS	66 min
Jul 4, 3:54 PM CDT	Severe Thunderstorm Warning	BIS	51 min
Jul 4, 4:15 PM CDT	Severe Thunderstorm Warning	BIS	45 min
Jul 4, 5:36 PM CDT	Special Weather Statement	GGW	54 min
Jul 14, 9:04 PM CDT	Special Weather Statement	BIS	41 min
Jul 14, 9:24 PM CDT	Special Weather Statement	BIS	51 min
Jul 14, 10:06 PM CDT	Special Weather Statement	BIS	39 min
Jul 15, 6:10 PM CDT	Severe Thunderstorm Warning	BIS	65 min
Jul 15, 7:06 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 22, 6:36 PM CDT	Special Weather Statement	BIS	24 min
Jul 26, 3:27 PM CDT	Tornado Warning Tornado observed	BIS	33 min
Jul 26, 3:58 PM CDT	Severe Thunderstorm Warning	BIS	62 min
Jul 27, 3:40 AM CDT	High Wind Watch	BIS	23 hr
Jul 27, 4:44 PM CDT	Mesoscale Discussion	SPC	3 hr
Jul 27, 6:51 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 27, 7:31 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 27, 8:38 PM CDT	Severe Thunderstorm Warning	BIS	67 min
Jul 27, 9:19 PM CDT	Mesoscale Discussion	SPC	116 min
Jul 27, 9:24 PM CDT	Severe Thunderstorm Warning	BIS	66 min
Jul 27, 11:46 PM CDT	Special Weather Statement	BIS	59 min
Jul 28, 2:33 AM CDT	High Wind Warning	BIS	22 hr
Aug 14, 4:10 AM CDT	Fire Weather Watch	BIS	12 hr
Aug 14, 3:50 PM CDT	Red Flag Warning	BIS	29 hr
Aug 21, 1:42 PM CDT	Wind Advisory	BIS	53 hr
Aug 28, 2:55 PM CDT	Fire Weather Watch	BIS	13 hr
Sep 10, 1:59 PM CDT	Frost Advisory	BIS	19 hr
Sep 17, 3:14 PM CDT	Frost Advisory	BIS	18 hr
Sep 28, 1:25 PM CDT	Frost Advisory	BIS	19 hr
Oct 10, 11:10 AM CDT	High Wind Watch	BIS	17 hr
Oct 11, 3:48 AM CDT	High Wind Warning	BIS	35 hr
Oct 15, 3:33 AM CDT	Freeze Warning	BIS	30 hr
Oct 26, 4:17 AM CDT	Dense Fog Advisory	BIS	8 hr
Oct 28, 3:44 AM CDT	Wind Advisory	BIS	15 hr
Oct 31, 3:46 AM CDT	Wind Advisory	BIS	15 hr
Nov 10, 12:45 AM CST	Dense Fog Advisory	BIS	11 hr
Nov 10, 2:47 PM CST	High Wind Watch	BIS	24 hr
Nov 11, 2:48 PM CST	Wind Advisory	BIS	27 hr
Nov 16, 7:32 AM CST	Dense Fog Advisory	BIS	4 hr
Nov 16, 2:49 PM CST	High Wind Watch	BIS	30 hr
Nov 17, 4:44 AM CST	High Wind Warning	BIS	55 hr
Nov 19, 3:33 AM CST	Wind Advisory	BIS	14 hr
Dec 12, 3:36 PM CST	Dense Fog Advisory	BIS	23 hr
Dec 20, 9:10 AM CST	Dense Fog Advisory	BIS	9 hr
Dec 20, 8:05 PM CST	Dense Fog Advisory	BIS	16 hr
Dec 25, 8:45 PM CST	Wind Chill Advisory	BIS	13 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	9
Tornado Warning	1
Severe Thunderstorm Watch	3
Tornado Watch	2
Mesoscale Discussion	12
Special Weather Statement	9
Flooding
Flash Flood Warning	2
River Flood Warning	2
Winter
Winter Storm Watch	1
Freezing Rain Advisory	3
Winter Weather Advisory	4
Cold
Freeze Warning	3
Wind Chill Warning	1
Frost Advisory	7
Wind Chill Advisory	14
Wind and dust
High Wind Warning	3
High Wind Watch	4
Wind Advisory	9
Fire
Red Flag Warning	7
Fire Weather Watch	7
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 2014 2016

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.