Weather alerts in Clarke County, Iowa, 2008

222 weather alerts in 2008, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Clarke County and its neighbors

Each county as a circle sized by its count in 2008. Tap one for its archive.

Alerts: 222
Warnings: 66
Watches: 53
Advisories: 49
Busiest month: June73 alerts
Busiest day: June 5, 200815 alerts

Over time

By month

Warning verification

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

5 of 13 tornado warnings covering Clarke County in 2008 had a tornado report inside them; 5 of 6 tornado reports fell inside a warning, on average 20 minutes after it went out.

Clarke County, 2008

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	13	5	62%	6	83%	20 min
Severe thunderstorm warnings	37	14	62%	6	33%	11 min
Flash flood warnings	7	6	14%	5	80%	129 min

Each office's whole area, 2008

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Des Moines, IA: tornado warnings	130	46	65%	124	81%	18 min
NWS Des Moines, IA: severe thunderstorm warnings	509	206	60%	734	77%	24 min
NWS Des Moines, IA: flash flood warnings	140	78	44%	232	82%	134 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 5, 7:09 AM CST	Dense Fog Advisory	DMX	6 hr
Jan 5, 3:35 PM CST	Dense Fog Advisory	DMX	22 hr
Jan 7, 7:26 AM CST	Mesoscale Discussion	SPC	2 hr
Jan 7, 3:38 PM CST	Dense Fog Advisory	DMX	14 hr
Jan 10, 2:32 PM CST	Snow Advisory	DMX	4 hr
Jan 11, 7:35 AM CST	Dense Fog Advisory	DMX	4 hr
Jan 15, 3:48 PM CST	Winter Storm Watch	DMX	19 hr
Jan 16, 10:50 AM CST	Snow Advisory	DMX	26 hr
Jan 18, 4:20 AM CST	Blowing Snow Advisory	DMX	9 hr
Jan 21, 7:10 PM CST	Winter Weather Advisory	DMX	5 hr
Jan 23, 4:09 AM CST	Wind Chill Advisory	DMX	27 hr
Jan 28, 3:58 PM CST	Wind Advisory	DMX	20 hr
Jan 29, 4:25 AM CST	Snow and Blowing Snow Advisory	DMX	14 hr
Jan 29, 7:39 AM CST	Winter Weather Advisory	DMX	11 hr
Feb 3, 3:52 AM CST	Freezing Fog Advisory	DMX	8 hr
Feb 4, 4:04 AM CST	Winter Storm Watch	DMX	24 hr
Feb 4, 10:37 AM CST	Dense Fog Advisory	DMX	10 hr
Feb 5, 3:58 AM CST	Winter Storm Warning	DMX	32 hr
Feb 6, 12:30 AM CST	Mesoscale Discussion	SPC	6 hr
Feb 6, 6:07 AM CST	Mesoscale Discussion	SPC	6 hr
Feb 7, 3:30 AM CST	Dense Fog Advisory	DMX	6 hr
Feb 9, 3:55 AM CST	Wind Chill Advisory	DMX	38 hr
Feb 15, 2:55 PM CST	Winter Storm Watch	DMX	25 hr
Feb 16, 3:57 AM CST	Blizzard Watch	DMX	24 hr
Feb 16, 3:49 PM CST	Winter Storm Warning	DMX	17 hr
Feb 16, 11:34 PM CST	Mesoscale Discussion	SPC	5 hr
Feb 17, 3:10 AM CST	Wind Advisory	DMX	17 hr
Feb 17, 3:46 AM CST	Blizzard Warning	DMX	10 hr
Feb 17, 3:46 AM CST	Snow and Blowing Snow Advisory	DMX	12 hr
Feb 17, 7:01 AM CST	Mesoscale Discussion	SPC	5 hr
Feb 17, 12:13 PM CST	Mesoscale Discussion	SPC	4 hr
Feb 19, 3:43 PM CST	Wind Chill Advisory	DMX	20 hr
Feb 24, 11:46 PM CST	Winter Weather Advisory	DMX	24 hr
Mar 2, 4:21 AM CST	Winter Weather Advisory	DMX	24 hr
Mar 2, 5:59 PM CST	Flash Flood Watch	DMX	12 hr
Mar 2, 6:55 PM CST	Mesoscale Discussion	SPC	6 hr
Mar 17, 10:15 PM CDT	Dense Fog Advisory	DMX	13 hr
Mar 31, 3:31 AM CDT	Mesoscale Discussion	SPC	59 min
Mar 31, 5:59 AM CDT	Mesoscale Discussion	SPC	91 min
Apr 9, 3:38 AM CDT	Dense Fog Advisory	DMX	6 hr
Apr 10, 4:17 AM CDT	Wind Advisory	DMX	17 hr
Apr 10, 2:28 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Apr 10, 4:24 PM CDT	Tornado Warning	DMX	51 min
Apr 10, 4:49 PM CDT	Tornado Warning	DMX	26 min
Apr 10, 4:55 PM CDT	Tornado Watch	SPC	5 hr
Apr 10, 6:44 PM CDT	Mesoscale Discussion	SPC	61 min
Apr 10, 9:52 PM CDT	Severe Thunderstorm Warning	DMX	38 min
Apr 15, 3:42 AM CDT	Wind Advisory	DMX	17 hr
Apr 16, 3:54 AM CDT	Wind Advisory	DMX	11 hr
Apr 17, 3:35 AM CDT	Flood Watch	DMX	39 hr
Apr 22, 5:04 AM CDT	Severe Thunderstorm Warning	DMX	41 min
Apr 22, 5:25 AM CDT	Severe Thunderstorm Warning	DMX	35 min
Apr 24, 3:56 PM CDT	Flash Flood Watch	DMX	20 hr
Apr 25, 12:07 AM CDT	Severe Thunderstorm Watch	SPC	7 hr
Apr 25, 2:24 AM CDT	Mesoscale Discussion	SPC	66 min
Apr 25, 3:19 AM CDT	Severe Thunderstorm Warning	DMX	41 min
Apr 25, 3:47 AM CDT	Severe Thunderstorm Warning	DMX	43 min
Apr 25, 4:22 AM CDT	Mesoscale Discussion	SPC	23 min
Apr 28, 3:48 AM CDT	Freeze Warning	DMX	29 hr
May 1, 5:36 PM CDT	Tornado Watch	SPC	7 hr
May 1, 10:04 PM CDT	Mesoscale Discussion	SPC	116 min
May 1, 11:29 PM CDT	Mesoscale Discussion	SPC	91 min
May 10, 4:22 AM CDT	Wind Advisory	DMX	32 hr
May 10, 3:47 PM CDT	Flash Flood Watch	DMX	12 hr
May 19, 6:21 PM CDT	Mesoscale Discussion	SPC	54 min
May 24, 9:27 AM CDT	Wind Advisory	DMX	3 hr
May 24, 3:49 PM CDT	Flash Flood Watch	DMX	39 hr
May 25, 3:30 PM CDT	Tornado Watch PDS	SPC	5 hr
May 25, 5:47 PM CDT	Severe Thunderstorm Warning	DMX	43 min
May 25, 6:12 PM CDT	Tornado Warning	DMX	48 min
May 25, 7:54 PM CDT	Tornado Watch	SPC	6 hr
May 25, 9:09 PM CDT	Severe Thunderstorm Warning	DMX	51 min
May 25, 9:23 PM CDT	Mesoscale Discussion	SPC	67 min
May 29, 3:19 AM CDT	Flash Flood Watch	DMX	28 hr
May 29, 7:37 PM CDT	Mesoscale Discussion	SPC	53 min
May 29, 8:13 PM CDT	Tornado Watch	SPC	8 hr
May 29, 11:34 PM CDT	Mesoscale Discussion	SPC	56 min
May 30, 1:19 AM CDT	Tornado Watch	SPC	8 hr
May 30, 1:41 AM CDT	Severe Thunderstorm Warning	DMX	49 min
May 30, 1:50 AM CDT	Severe Thunderstorm Warning	DMX	40 min
May 30, 2:17 AM CDT	Mesoscale Discussion	SPC	88 min
May 30, 4:05 AM CDT	Tornado Warning	DMX	40 min
May 30, 4:25 AM CDT	Severe Thunderstorm Warning	DMX	50 min
May 30, 4:40 AM CDT	Tornado Warning	DMX	19 min
Jun 2, 3:40 PM CDT	Flash Flood Watch	DMX	19 hr
Jun 2, 8:02 PM CDT	Mesoscale Discussion	SPC	118 min
Jun 2, 9:15 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jun 3, 4:33 AM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 3, 5:46 AM CDT	Severe Thunderstorm Warning	DMX	44 min
Jun 3, 6:31 AM CDT	Severe Thunderstorm Warning	DMX	44 min
Jun 3, 6:49 AM CDT	Mesoscale Discussion	SPC	86 min
Jun 4, 4:16 AM CDT	Flash Flood Watch	DMX	27 hr
Jun 4, 4:09 PM CDT	Mesoscale Discussion	SPC	66 min
Jun 4, 5:40 PM CDT	Tornado Watch	SPC	6 hr
Jun 4, 6:47 PM CDT	Mesoscale Discussion	SPC	58 min
Jun 4, 7:30 PM CDT	Tornado Warning	DMX	30 min
Jun 4, 8:00 PM CDT	Severe Thunderstorm Warning	DMX	31 min
Jun 4, 9:33 PM CDT	Mesoscale Discussion	SPC	87 min
Jun 4, 9:38 PM CDT	Tornado Warning	DMX	52 min
Jun 4, 10:28 PM CDT	Tornado Warning	DMX	47 min
Jun 4, 10:44 PM CDT	Flash Flood Warning	DMX	6 hr
Jun 4, 11:34 PM CDT	Severe Thunderstorm Warning	DMX	41 min
Jun 4, 11:56 PM CDT	Tornado Watch	SPC	5 hr
Jun 5, 2:02 AM CDT	Severe Thunderstorm Warning	DMX	43 min
Jun 5, 2:12 AM CDT	Severe Thunderstorm Warning	DMX	43 min
Jun 5, 2:26 AM CDT	Severe Thunderstorm Warning	DMX	49 min
Jun 5, 2:33 AM CDT	Tornado Warning	DMX	21 min
Jun 5, 4:11 AM CDT	Mesoscale Discussion	SPC	94 min
Jun 5, 4:17 AM CDT	Flash Flood Watch	DMX	24 hr
Jun 5, 5:50 PM CDT	Tornado Watch PDS	SPC	7 hr
Jun 5, 7:44 PM CDT	Mesoscale Discussion	SPC	91 min
Jun 5, 9:37 PM CDT	Severe Thunderstorm Warning	DMX	38 min
Jun 5, 10:01 PM CDT	Severe Thunderstorm Warning	DMX	44 min
Jun 5, 11:00 PM CDT	Flash Flood Warning	DMX	5 hr
Jun 5, 11:42 PM CDT	Tornado Warning	DMX	33 min
Jun 6, 3:50 AM CDT	Wind Advisory	DMX	12 hr
Jun 7, 4:32 AM CDT	Flash Flood Watch	DMX	46 hr
Jun 8, 3:05 AM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 8, 6:39 AM CDT	Mesoscale Discussion	SPC	66 min
Jun 8, 12:28 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 8, 1:21 PM CDT	Tornado Watch	SPC	7 hr
Jun 8, 3:47 PM CDT	Mesoscale Discussion	SPC	118 min
Jun 8, 4:25 PM CDT	Tornado Warning	DMX	20 min
Jun 8, 4:41 PM CDT	Flash Flood Warning	DMX	3 hr
Jun 8, 4:44 PM CDT	Severe Thunderstorm Warning	DMX	24 min
Jun 8, 4:55 PM CDT	Tornado Warning	DMX	35 min
Jun 11, 8:05 PM CDT	Mesoscale Discussion	SPC	115 min
Jun 11, 8:39 PM CDT	Tornado Watch	SPC	5 hr
Jun 11, 9:58 PM CDT	Mesoscale Discussion	SPC	92 min
Jun 11, 11:41 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 12, 3:52 PM CDT	Mesoscale Discussion	SPC	113 min
Jun 14, 1:11 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jun 15, 6:54 AM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 19, 1:14 PM CDT	Mesoscale Discussion	SPC	61 min
Jun 19, 1:27 PM CDT	Severe Thunderstorm Watch	SPC	10 hr
Jun 19, 1:45 PM CDT	Severe Thunderstorm Warning	DMX	45 min
Jun 19, 2:21 PM CDT	Severe Thunderstorm Warning	DMX	39 min
Jun 19, 2:27 PM CDT	Tornado Warning	DMX	33 min
Jun 20, 1:54 PM CDT	Mesoscale Discussion	SPC	96 min
Jun 20, 5:57 PM CDT	Mesoscale Discussion	SPC	63 min
Jun 20, 6:53 PM CDT	Severe Thunderstorm Warning	DMX	52 min
Jun 24, 6:03 AM CDT	Mesoscale Discussion	SPC	117 min
Jun 25, 7:06 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 25, 10:18 PM CDT	Mesoscale Discussion	SPC	87 min
Jun 25, 10:24 PM CDT	Severe Thunderstorm Warning	DMX	51 min
Jun 25, 11:10 PM CDT	Severe Thunderstorm Warning	DMX	50 min
Jun 25, 11:13 PM CDT	Severe Thunderstorm Warning	DMX	47 min
Jun 25, 11:53 PM CDT	Severe Thunderstorm Warning	DMX	33 min
Jun 26, 4:01 AM CDT	Flash Flood Watch	DMX	42 hr
Jun 26, 6:38 AM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 26, 9:53 AM CDT	Mesoscale Discussion	SPC	97 min
Jun 26, 10:55 AM CDT	Areal Flood Advisory	DMX	3 hr
Jun 26, 12:05 PM CDT	Mesoscale Discussion	SPC	55 min
Jun 27, 5:33 PM CDT	Mesoscale Discussion	SPC	87 min
Jun 27, 5:46 PM CDT	Severe Thunderstorm Watch	SPC	4 hr
Jun 27, 6:50 PM CDT	Severe Thunderstorm Warning	DMX	40 min
Jun 27, 7:15 PM CDT	Severe Thunderstorm Warning	DMX	45 min
Jul 2, 5:56 PM CDT	Severe Thunderstorm Warning	DMX	49 min
Jul 2, 6:41 PM CDT	Flash Flood Warning	DMX	3 hr
Jul 6, 5:48 AM CDT	Mesoscale Discussion	SPC	117 min
Jul 7, 1:05 PM CDT	Mesoscale Discussion	SPC	115 min
Jul 7, 11:15 PM CDT	Severe Thunderstorm Warning	DMX	45 min
Jul 8, 12:57 AM CDT	Flash Flood Warning	DMX	6 hr
Jul 11, 10:31 PM CDT	Mesoscale Discussion	SPC	89 min
Jul 11, 10:40 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Jul 12, 1:52 AM CDT	Mesoscale Discussion	SPC	53 min
Jul 18, 3:43 AM CDT	Flash Flood Watch	DMX	22 hr
Jul 19, 7:59 PM CDT	Tornado Watch	SPC	4 hr
Jul 20, 10:17 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 20, 11:25 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 21, 3:10 AM CDT	Mesoscale Discussion	SPC	95 min
Jul 21, 1:48 PM CDT	Mesoscale Discussion	SPC	87 min
Jul 21, 5:10 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 24, 4:00 PM CDT	Flash Flood Watch	DMX	15 hr
Jul 25, 6:12 AM CDT	Areal Flood Warning	DMX	22 hr
Jul 26, 4:22 AM CDT	Flash Flood Watch	DMX	10 hr
Jul 27, 2:29 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 27, 4:31 PM CDT	Severe Thunderstorm Warning	DMX	44 min
Jul 27, 4:57 PM CDT	Severe Thunderstorm Warning	DMX	48 min
Jul 27, 5:13 PM CDT	Severe Thunderstorm Warning	DMX	47 min
Jul 27, 6:22 PM CDT	Mesoscale Discussion	SPC	83 min
Jul 27, 11:30 PM CDT	Severe Thunderstorm Watch	SPC	9 hr
Jul 28, 12:24 AM CDT	Severe Thunderstorm Warning	DMX	38 min
Jul 28, 1:18 AM CDT	Flash Flood Warning	DMX	6 hr
Jul 28, 1:23 AM CDT	Mesoscale Discussion	SPC	97 min
Jul 28, 2:15 AM CDT	Severe Thunderstorm Warning	DMX	45 min
Jul 28, 3:03 AM CDT	Severe Thunderstorm Warning	DMX	23 min
Jul 28, 5:31 AM CDT	Mesoscale Discussion	SPC	89 min
Jul 28, 7:13 AM CDT	Areal Flood Warning	DMX	12 hr
Jul 31, 6:39 AM CDT	Dense Fog Advisory	DMX	3 hr
Jul 31, 6:30 PM CDT	Mesoscale Discussion	SPC	90 min
Aug 3, 3:53 AM CDT	Heat Advisory	DMX	39 hr
Aug 13, 2:59 AM CDT	Dense Fog Advisory	DMX	6 hr
Aug 28, 3:22 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Sep 5, 3:19 AM CDT	Dense Fog Advisory	DMX	6 hr
Sep 6, 2:45 AM CDT	Dense Fog Advisory	DMX	8 hr
Sep 12, 3:48 AM CDT	Flash Flood Watch	DMX	32 hr
Sep 12, 6:56 PM CDT	Areal Flood Advisory	DMX	5 hr
Sep 12, 9:16 PM CDT	Flash Flood Warning	DMX	119 min
Sep 24, 3:28 PM CDT	Dense Fog Advisory	DMX	17 hr
Sep 29, 12:39 AM CDT	Mesoscale Discussion	SPC	96 min
Oct 15, 3:44 PM CDT	Frost Advisory	DMX	17 hr
Oct 18, 3:08 AM CDT	Dense Fog Advisory	DMX	7 hr
Oct 25, 2:59 PM CDT	High Wind Watch	DMX	12 hr
Oct 26, 3:27 AM CDT	High Wind Warning	DMX	16 hr
Oct 31, 10:15 PM CDT	Dense Fog Advisory	DMX	12 hr
Nov 1, 9:15 PM CDT	Dense Fog Advisory	DMX	14 hr
Nov 12, 1:54 AM CST	Dense Fog Advisory	DMX	8 hr
Nov 29, 3:15 PM CST	Winter Weather Advisory	DMX	27 hr
Dec 7, 4:04 AM CST	Winter Storm Watch	DMX	36 hr
Dec 8, 4:18 PM CST	Winter Weather Advisory	DMX	26 hr
Dec 14, 3:38 AM CST	Wind Chill Advisory	DMX	44 hr
Dec 15, 4:11 AM CST	Winter Storm Watch	DMX	11 hr
Dec 15, 3:39 PM CST	Winter Weather Advisory	DMX	29 hr
Dec 16, 3:51 PM CST	Winter Storm Watch	DMX	36 hr
Dec 17, 3:51 PM CST	Ice Storm Warning	DMX	38 hr
Dec 18, 6:46 PM CST	Mesoscale Discussion	SPC	6 hr
Dec 20, 3:48 AM CST	Wind Chill Advisory	DMX	48 hr
Dec 26, 9:47 PM CST	Flash Flood Watch	DMX	13 hr
Dec 27, 4:13 AM CST	Winter Weather Advisory	DMX	11 hr
Dec 27, 7:24 AM CST	Ice Storm Warning	DMX	6 hr
Dec 30, 3:35 AM CST	Wind Advisory	DMX	17 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	37
Tornado Warning	13
Severe Thunderstorm Watch	17
Tornado Watch	12
Mesoscale Discussion	54
Flooding
Areal Flood Warning	2
Flash Flood Warning	7
Flash Flood Watch	15
Flood Watch	1
Areal Flood Advisory	2
Winter
Blizzard Warning	1
Ice Storm Warning	2
Winter Storm Warning	2
Blizzard Watch	1
Winter Storm Watch	6
Blowing Snow Advisory	1
Snow Advisory	2
Snow and Blowing Snow Advisory	2
Winter Weather Advisory	8
Heat
Heat Advisory	1
Cold
Freeze Warning	1
Frost Advisory	1
Wind Chill Advisory	5
Wind and dust
High Wind Warning	1
High Wind Watch	1
Wind Advisory	9
Fog and smoke
Dense Fog Advisory	17
Freezing Fog Advisory	1

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2007 2009

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.