Alert archive / North Dakota / Mercer County

Weather alerts in Mercer County, North Dakota, 2009

141 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Mercer County and its neighbors

Each county as a circle sized by its count in 2009. Tap one for its archive.

Alerts: 141
Warnings: 46
Watches: 22
Advisories: 52
Busiest month: March24 alerts
Busiest day: July 9, 20099 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 4 tornado warnings covering Mercer County in 2009 had a tornado report inside them.

Mercer County, 2009

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	4	0	100%	0
Severe thunderstorm warnings	19	8	58%	4	75%	14 min
Flash flood warnings	0			0

Each office's whole area, 2009

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Bismarck, ND: tornado warnings	56	11	80%	19	79%	13 min
NWS Bismarck, ND: severe thunderstorm warnings	180	61	66%	124	70%	23 min
NWS Bismarck, ND: flash flood warnings	15	2	87%	2	100%	46 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 2, 4:09 AM MST	Winter Weather Advisory	BIS	40 hr
Jan 3, 4:12 AM MST	Winter Weather Advisory	BIS	16 hr
Jan 3, 2:29 PM MST	Wind Chill Advisory	BIS	25 hr
Jan 7, 2:42 PM MST	Winter Storm Warning	BIS	48 hr
Jan 7, 2:42 PM MST	Winter Weather Advisory	BIS	50 hr
Jan 10, 2:05 PM MST	Blizzard Watch	BIS	13 hr
Jan 11, 3:25 AM MST	Blizzard Warning	BIS	32 hr
Jan 12, 4:34 AM MST	Mesoscale Discussion	SPC	4 hr
Jan 13, 3:51 AM MST	Wind Chill Advisory	BIS	34 hr
Jan 13, 3:51 AM MST	Winter Weather Advisory	BIS	19 hr
Jan 14, 10:23 AM MST	Wind Chill Warning	BIS	7 hr
Jan 16, 7:52 PM MST	Winter Weather Advisory	BIS	31 hr
Jan 22, 3:03 PM MST	Wind Chill Advisory	BIS	4 days
Jan 22, 3:03 PM MST	Winter Weather Advisory	BIS	14 hr
Jan 31, 3:43 AM MST	High Wind Warning	BIS	13 hr
Jan 31, 3:43 AM MST	Wind Advisory	BIS	17 hr
Jan 31, 10:10 AM MST	Wind Advisory	BIS	7 hr
Feb 1, 3:14 AM MST	Wind Advisory	BIS	15 hr
Feb 7, 2:58 PM MST	Winter Storm Watch	BIS	24 hr
Feb 8, 3:15 PM MST	Winter Storm Warning	BIS	59 hr
Feb 9, 9:57 AM MST	Dense Fog Advisory	BIS	10 hr
Feb 9, 4:52 PM MST	Mesoscale Discussion	SPC	4 hr
Feb 10, 2:56 AM MST	Winter Weather Advisory	BIS	23 hr
Feb 20, 3:00 AM MST	Winter Weather Advisory	BIS	17 hr
Feb 23, 2:58 PM MST	Freezing Rain Advisory	BIS	23 hr
Feb 25, 2:21 PM MST	Wind Chill Advisory	BIS	21 hr
Feb 26, 3:00 PM MST	Wind Chill Advisory	BIS	20 hr
Mar 8, 3:03 AM MDT	Winter Storm Watch	BIS	36 hr
Mar 9, 3:25 PM MDT	Winter Weather Advisory	BIS	27 hr
Mar 10, 3:18 PM MDT	Wind Chill Warning	BIS	20 hr
Mar 11, 10:55 AM MDT	Wind Chill Advisory	BIS	24 hr
Mar 14, 12:54 PM MDT	Areal Flood Advisory	BIS	24 hr
Mar 15, 1:03 PM MDT	Areal Flood Advisory	BIS	24 hr
Mar 16, 1:23 PM MDT	Areal Flood Advisory	BIS	51 hr
Mar 18, 4:17 PM MDT	Areal Flood Advisory	BIS	3 days
Mar 20, 2:09 PM MDT	Flood Watch	BIS	4 days
Mar 21, 4:15 AM MDT	Blizzard Watch	BIS	48 hr
Mar 21, 10:15 AM MDT	River Flood Warning	BIS	6 days
Mar 21, 10:15 AM MDT	River Flood Warning	BIS	3 days
Mar 21, 9:13 PM MDT	Areal Flood Warning	BIS	12 hr
Mar 22, 4:05 AM MDT	Wind Advisory	BIS	16 hr
Mar 22, 9:22 AM MDT	Areal Flood Warning	BIS	5 days
Mar 22, 4:04 PM MDT	Blizzard Warning	BIS	50 hr
Mar 22, 9:03 PM MDT	Dense Fog Advisory	BIS	156 days
Mar 22, 9:03 PM MDT	Dense Fog Advisory	BIS	12 hr
Mar 23, 5:56 PM MDT	Mesoscale Discussion	SPC	3 hr
Mar 24, 6:03 PM MDT	Winter Weather Advisory	BIS	9 hr
Mar 25, 3:04 PM MDT	Winter Weather Advisory	BIS	12 hr
Mar 26, 11:43 AM MDT	Winter Weather Advisory	BIS	7 hr
Mar 27, 2:20 PM MDT	Areal Flood Warning	BIS	4 days
Mar 29, 4:29 AM MDT	Winter Weather Advisory	BIS	59 hr
Apr 10, 5:06 AM MDT	River Flood Warning	BIS	5 days
Apr 10, 9:29 AM MDT	River Flood Warning	BIS	7 days
Apr 12, 12:21 PM MDT	Areal Flood Warning	BIS	8 days
Apr 15, 10:38 AM MDT	Wind Advisory	BIS	9 hr
Apr 21, 3:25 AM MDT	Areal Flood Warning	BIS	11 hr
Apr 21, 2:02 PM MDT	Areal Flood Warning	BIS	48 hr
May 12, 2:19 PM MDT	Mesoscale Discussion	SPC	56 min
May 12, 2:36 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
May 12, 4:03 PM MDT	Severe Thunderstorm Warning	BIS	57 min
May 12, 5:06 PM MDT	Severe Thunderstorm Warning	BIS	39 min
May 13, 2:27 AM MDT	Wind Advisory	BIS	18 hr
May 14, 2:15 PM MDT	Freeze Watch	BIS	25 hr
May 15, 2:46 PM MDT	Freeze Warning	BIS	17 hr
May 17, 3:57 AM MDT	Freeze Watch	BIS	35 hr
Jun 2, 2:32 PM MDT	Frost Advisory	BIS	16 hr
Jun 10, 3:16 PM MDT	Frost Advisory	BIS	16 hr
Jun 16, 12:23 PM MDT	Mesoscale Discussion	SPC	97 min
Jun 16, 3:43 PM MDT	Areal Flood Advisory	BIS	6 hr
Jun 21, 12:57 PM MDT	Mesoscale Discussion	SPC	93 min
Jun 21, 4:43 PM MDT	Mesoscale Discussion	SPC	92 min
Jun 22, 12:29 PM MDT	Mesoscale Discussion	SPC	2 hr
Jun 22, 2:06 PM MDT	Severe Thunderstorm Watch	SPC	5 hr
Jun 22, 2:29 PM MDT	Severe Thunderstorm Warning	BIS	61 min
Jun 22, 2:43 PM MDT	Severe Thunderstorm Warning	BIS	62 min
Jun 22, 3:18 PM MDT	Severe Thunderstorm Warning	BIS	42 min
Jun 22, 5:28 PM MDT	Mesoscale Discussion	SPC	92 min
Jun 26, 1:13 PM MDT	Mesoscale Discussion	SPC	62 min
Jun 26, 1:53 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 26, 4:47 PM MDT	Severe Thunderstorm Warning	BIS	58 min
Jun 26, 5:22 PM MDT	Severe Thunderstorm Warning	BIS	53 min
Jun 26, 5:23 PM MDT	Tornado Warning	BIS	37 min
Jun 26, 5:43 PM MDT	Tornado Watch	SPC	4 hr
Jun 26, 6:17 PM MDT	Severe Thunderstorm Warning	BIS	58 min
Jun 26, 7:08 PM MDT	Severe Thunderstorm Warning	BIS	52 min
Jun 27, 12:39 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 27, 2:16 PM MDT	Mesoscale Discussion	SPC	59 min
Jul 7, 5:43 AM MDT	Areal Flood Advisory	BIS	6 hr
Jul 8, 2:20 PM MDT	Tornado Watch	SPC	8 hr
Jul 8, 5:46 PM MDT	Mesoscale Discussion	SPC	89 min
Jul 8, 7:58 PM MDT	Severe Thunderstorm Warning	BIS	62 min
Jul 8, 8:42 PM MDT	Mesoscale Discussion	SPC	93 min
Jul 8, 8:43 PM MDT	Tornado Warning	BIS	32 min
Jul 8, 8:54 PM MDT	Severe Thunderstorm Warning	BIS	66 min
Jul 8, 9:13 PM MDT	Tornado Warning	BIS	32 min
Jul 8, 9:23 PM MDT	Areal Flood Advisory	BIS	6 hr
Jul 8, 9:29 PM MDT	Severe Thunderstorm Watch PDS	SPC	6 hr
Jul 8, 9:55 PM MDT	Severe Thunderstorm Warning	BIS	65 min
Jul 8, 10:27 PM MDT	Mesoscale Discussion	SPC	93 min
Jul 11, 7:01 PM MDT	Mesoscale Discussion	SPC	59 min
Jul 11, 10:12 PM MDT	Severe Thunderstorm Warning	BIS	63 min
Jul 11, 10:48 PM MDT	Severe Thunderstorm Warning	BIS	57 min
Jul 11, 11:00 PM MDT	Tornado Warning	BIS	30 min
Jul 11, 11:29 PM MDT	Severe Thunderstorm Warning	BIS	38 min
Jul 19, 6:28 PM MDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 19, 6:44 PM MDT	Severe Thunderstorm Warning	BIS	61 min
Jul 19, 7:17 PM MDT	Severe Thunderstorm Warning	BIS	58 min
Aug 2, 1:35 PM MDT	Mesoscale Discussion	SPC	115 min
Aug 13, 11:33 PM MDT	Mesoscale Discussion	SPC	87 min
Aug 14, 4:16 AM MDT	Severe Thunderstorm Warning	BIS	41 min
Aug 19, 11:16 AM MDT	Mesoscale Discussion	SPC	119 min
Aug 23, 7:02 PM MDT	Mesoscale Discussion	SPC	88 min
Aug 23, 7:55 PM MDT	Tornado Watch	SPC	5 hr
Aug 24, 12:48 AM MDT	Severe Thunderstorm Watch	SPC	4 hr
Sep 8, 12:44 AM MDT	Mesoscale Discussion	SPC	91 min
Sep 8, 1:38 AM MDT	Severe Thunderstorm Warning	BIS	67 min
Sep 10, 3:53 PM MDT	Mesoscale Discussion	SPC	97 min
Sep 26, 2:20 PM MDT	Wind Advisory	BIS	30 hr
Sep 28, 2:38 AM MDT	Frost Advisory	BIS	29 hr
Sep 30, 2:52 PM MDT	Wind Advisory	BIS	30 hr
Oct 5, 3:14 AM MDT	Freeze Watch	BIS	12 hr
Oct 5, 3:14 PM MDT	Freeze Warning	BIS	18 hr
Oct 7, 3:18 AM MDT	Freeze Watch	BIS	11 hr
Oct 7, 2:19 PM MDT	Freeze Warning	BIS	21 hr
Oct 8, 3:54 AM MDT	Freeze Warning	BIS	29 hr
Oct 14, 3:55 AM MDT	Winter Weather Advisory	BIS	31 hr
Oct 27, 3:07 PM MDT	Winter Storm Watch	BIS	44 hr
Oct 28, 2:46 PM MDT	Winter Weather Advisory	BIS	36 hr
Nov 30, 3:01 PM MST	Wind Advisory	BIS	26 hr
Dec 8, 1:15 PM MST	Wind Chill Advisory	BIS	44 hr
Dec 12, 3:57 AM MST	Wind Chill Advisory	BIS	31 hr
Dec 13, 2:49 PM MST	Wind Chill Advisory	BIS	20 hr
Dec 14, 3:04 PM MST	Wind Chill Advisory	BIS	20 hr
Dec 16, 9:30 PM MST	Freezing Rain Advisory	BIS	6 hr
Dec 18, 7:23 PM MST	Freezing Fog Advisory	BIS	15 hr
Dec 20, 2:43 AM MST	Freezing Fog Advisory	BIS	11 hr
Dec 22, 2:44 AM MST	Winter Storm Watch	BIS	24 hr
Dec 23, 2:15 AM MST	Blizzard Watch	BIS	37 hr
Dec 23, 2:15 AM MST	Winter Storm Warning	BIS	51 hr
Dec 23, 2:15 AM MST	Winter Weather Advisory	BIS	4 days
Dec 24, 2:17 AM MST	Blizzard Warning	BIS	68 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	19
Tornado Warning	4
Severe Thunderstorm Watch	7
Tornado Watch	3
Mesoscale Discussion	21
Flooding
Areal Flood Warning	6
River Flood Warning	4
Flood Watch	1
Areal Flood Advisory	7
Winter
Blizzard Warning	3
Winter Storm Warning	3
Blizzard Watch	3
Winter Storm Watch	4
Freezing Rain Advisory	2
Winter Weather Advisory	16
Cold
Freeze Warning	4
Wind Chill Warning	2
Freeze Watch	4
Frost Advisory	3
Wind Chill Advisory	10
Wind and dust
High Wind Warning	1
Wind Advisory	9
Fog and smoke
Dense Fog Advisory	3
Freezing Fog Advisory	2

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2008 2010

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.