Weather alerts in Shelby County, Iowa, 2008

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

Shelby County and its neighbors

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

Alerts: 170
Warnings: 38
Watches: 35
Advisories: 44
Busiest month: June62 alerts
Busiest day: June 12, 20089 alerts

Over time

By month

Warning verification

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

3 of 7 tornado warnings covering Shelby County in 2008 had a tornado report inside them; 2 of 2 tornado reports fell inside a warning, on average 6 minutes after it went out.

Shelby County, 2008

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	7	3	57%	2	100%	6 min
Severe thunderstorm warnings	25	12	52%	8	75%	18 min
Flash flood warnings	1	0	100%	0

Each office's whole area, 2008

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Omaha, NE: tornado warnings	64	24	63%	55	76%	17 min
NWS Omaha, NE: severe thunderstorm warnings	457	150	67%	322	82%	20 min
NWS Omaha, NE: flash flood warnings	65	17	74%	27	89%	86 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 15, 3:49 PM CST	Snow Advisory	OAX	11 hr
Jan 16, 3:04 AM CST	Snow and Blowing Snow Advisory	OAX	18 hr
Jan 16, 9:18 PM CST	Snow Advisory	OAX	12 hr
Jan 18, 4:02 AM CST	Wind Chill Advisory	OAX	23 hr
Jan 22, 3:46 PM CST	Blowing Snow Advisory	OAX	25 hr
Jan 28, 3:32 PM CST	Winter Weather Advisory	OAX	24 hr
Jan 28, 3:43 PM CST	Wind Advisory	OAX	23 hr
Jan 29, 7:39 AM CST	Mesoscale Discussion	SPC	5 hr
Feb 3, 9:51 PM CST	Winter Weather Advisory	OAX	14 hr
Feb 4, 3:31 PM CST	Snow Advisory	OAX	32 hr
Feb 5, 9:32 PM CST	Snow and Blowing Snow Advisory	OAX	5 hr
Feb 9, 3:30 PM CST	Wind Chill Advisory	OAX	21 hr
Feb 16, 4:03 PM CST	Winter Weather Advisory	OAX	18 hr
Feb 16, 4:06 PM CST	Wind Advisory	OAX	26 hr
Feb 19, 3:37 PM CST	Wind Chill Advisory	OAX	19 hr
Feb 20, 3:55 AM CST	Wind Chill Warning	OAX	6 hr
Feb 24, 9:30 AM CST	Air Stagnation Advisory	OAX	4 hr
Feb 24, 3:37 PM CST	Winter Weather Advisory	OAX	24 hr
Feb 25, 9:30 AM CST	Mesoscale Discussion	SPC	6 hr
Mar 2, 4:15 AM CST	Winter Weather Advisory	OAX	20 hr
Mar 17, 10:17 PM CDT	Dense Fog Advisory	OAX	12 hr
Apr 9, 7:22 AM CDT	Dense Fog Advisory	OAX	98 min
Apr 9, 9:02 AM CDT	Dense Fog Advisory	OAX	54 min
Apr 10, 2:28 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Apr 14, 3:27 PM CDT	Wind Advisory	OAX	30 hr
Apr 24, 5:37 PM CDT	Severe Thunderstorm Warning	OAX	23 min
Apr 24, 5:59 PM CDT	Severe Thunderstorm Warning	OAX	46 min
Apr 24, 6:44 PM CDT	Severe Thunderstorm Warning	OAX	31 min
May 6, 2:50 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
May 6, 6:23 PM CDT	Mesoscale Discussion	SPC	2 hr
May 6, 9:13 PM CDT	Mesoscale Discussion	SPC	62 min
May 10, 4:07 AM CDT	Wind Advisory	OAX	27 hr
May 24, 9:01 PM CDT	Mesoscale Discussion	SPC	59 min
May 25, 8:44 PM CDT	Severe Thunderstorm Warning	OAX	31 min
May 29, 5:32 AM CDT	Mesoscale Discussion	SPC	118 min
May 29, 5:35 AM CDT	Flash Flood Watch	OAX	22 hr
May 29, 5:55 PM CDT	Mesoscale Discussion	SPC	35 min
May 29, 6:43 PM CDT	Tornado Watch	SPC	7 hr
May 29, 8:03 PM CDT	Tornado Warning	OAX	27 min
May 29, 8:22 PM CDT	Severe Thunderstorm Warning	OAX	23 min
May 29, 8:44 PM CDT	Severe Thunderstorm Warning	OAX	31 min
May 29, 9:14 PM CDT	Severe Thunderstorm Warning	OAX	31 min
May 29, 10:51 PM CDT	Severe Thunderstorm Warning	OAX	39 min
May 29, 11:34 PM CDT	Mesoscale Discussion	SPC	56 min
May 30, 1:37 AM CDT	Mesoscale Discussion	SPC	53 min
Jun 3, 1:57 AM CDT	Severe Thunderstorm Watch	SPC	3 hr
Jun 3, 4:07 AM CDT	Severe Thunderstorm Warning	OAX	23 min
Jun 3, 4:12 AM CDT	Mesoscale Discussion	SPC	2 hr
Jun 3, 4:23 AM CDT	Severe Thunderstorm Warning	OAX	37 min
Jun 3, 4:33 AM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 4, 3:30 PM CDT	Flash Flood Watch	OAX	31 hr
Jun 4, 5:40 PM CDT	Tornado Watch	SPC	6 hr
Jun 4, 6:47 PM CDT	Mesoscale Discussion	SPC	58 min
Jun 4, 9:17 PM CDT	Severe Thunderstorm Warning	OAX	58 min
Jun 4, 9:33 PM CDT	Mesoscale Discussion	SPC	87 min
Jun 4, 10:12 PM CDT	Severe Thunderstorm Warning	OAX	27 min
Jun 4, 11:56 PM CDT	Tornado Watch	SPC	5 hr
Jun 5, 4:12 AM CDT	Wind Advisory	OAX	17 hr
Jun 5, 10:55 AM CDT	Tornado Watch PDS	SPC	8 hr
Jun 5, 5:10 PM CDT	Mesoscale Discussion	SPC	95 min
Jun 5, 5:50 PM CDT	Tornado Watch PDS	SPC	7 hr
Jun 5, 7:44 PM CDT	Mesoscale Discussion	SPC	91 min
Jun 7, 4:30 AM CDT	Flash Flood Watch	OAX	39 hr
Jun 7, 3:29 PM CDT	Mesoscale Discussion	SPC	3 hr
Jun 7, 4:25 PM CDT	Tornado Watch	SPC	7 hr
Jun 7, 6:34 PM CDT	Mesoscale Discussion	SPC	56 min
Jun 7, 11:11 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 8, 2:29 AM CDT	Mesoscale Discussion	SPC	31 min
Jun 8, 2:47 AM CDT	Severe Thunderstorm Warning	OAX	43 min
Jun 8, 12:28 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 9, 8:22 PM CDT	Severe Thunderstorm Warning	OAX	53 min
Jun 11, 4:44 AM CDT	Flash Flood Watch	OAX	26 hr
Jun 11, 5:55 AM CDT	Severe Thunderstorm Warning	OAX	39 min
Jun 11, 6:26 AM CDT	Wind Advisory	OAX	10 hr
Jun 11, 2:03 PM CDT	Mesoscale Discussion	SPC	117 min
Jun 11, 2:52 PM CDT	Tornado Watch	SPC	7 hr
Jun 11, 5:59 PM CDT	Mesoscale Discussion	SPC	91 min
Jun 11, 7:16 PM CDT	Severe Thunderstorm Warning	OAX	29 min
Jun 11, 7:30 PM CDT	Tornado Warning	OAX	30 min
Jun 11, 7:37 PM CDT	Severe Thunderstorm Warning	OAX	38 min
Jun 11, 7:39 PM CDT	Tornado Warning	OAX	17 min
Jun 11, 7:47 PM CDT	Tornado Warning	OAX	28 min
Jun 11, 8:02 PM CDT	Tornado Warning	OAX	28 min
Jun 11, 8:09 PM CDT	Flash Flood Warning	OAX	3 hr
Jun 11, 8:15 PM CDT	Tornado Warning	OAX	18 min
Jun 11, 8:57 PM CDT	Mesoscale Discussion	SPC	93 min
Jun 15, 6:41 AM CDT	Mesoscale Discussion	SPC	64 min
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, 1:42 PM CDT	Severe Thunderstorm Warning	OAX	48 min
Jun 19, 6:11 PM CDT	Mesoscale Discussion	SPC	64 min
Jun 20, 1:54 PM CDT	Mesoscale Discussion	SPC	96 min
Jun 20, 4:32 PM CDT	Severe Thunderstorm Warning	OAX	43 min
Jun 20, 5:24 PM CDT	Severe Thunderstorm Warning	OAX	23 min
Jun 21, 3:05 PM CDT	Mesoscale Discussion	SPC	85 min
Jun 24, 6:03 AM CDT	Mesoscale Discussion	SPC	117 min
Jun 25, 5:51 PM CDT	Mesoscale Discussion	SPC	84 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 26, 3:48 AM CDT	Mesoscale Discussion	SPC	87 min
Jun 26, 6:38 AM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 26, 7:51 AM CDT	Mesoscale Discussion	SPC	84 min
Jun 26, 9:53 AM CDT	Mesoscale Discussion	SPC	97 min
Jun 26, 12:05 PM CDT	Mesoscale Discussion	SPC	55 min
Jun 26, 9:46 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 28, 3:52 AM CDT	Wind Advisory	OAX	14 hr
Jul 2, 1:19 PM CDT	Mesoscale Discussion	SPC	116 min
Jul 6, 3:05 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 7, 1:05 PM CDT	Mesoscale Discussion	SPC	115 min
Jul 7, 1:51 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 7, 3:14 PM CDT	Mesoscale Discussion	SPC	91 min
Jul 7, 3:41 PM CDT	Severe Thunderstorm Warning	OAX	34 min
Jul 7, 4:49 PM CDT	Severe Thunderstorm Warning	OAX	26 min
Jul 7, 5:55 PM CDT	Mesoscale Discussion	SPC	95 min
Jul 9, 1:33 PM CDT	Mesoscale Discussion	SPC	57 min
Jul 11, 5:08 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 11, 8:29 PM CDT	Mesoscale Discussion	SPC	91 min
Jul 11, 10:31 PM CDT	Mesoscale Discussion	SPC	89 min
Jul 11, 10:40 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Jul 11, 10:52 PM CDT	Severe Thunderstorm Warning	OAX	38 min
Jul 12, 3:26 AM CDT	Mesoscale Discussion	SPC	64 min
Jul 15, 4:30 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 17, 5:50 PM CDT	Mesoscale Discussion	SPC	85 min
Jul 19, 2:28 PM CDT	Tornado Watch	SPC	8 hr
Jul 19, 8:55 PM CDT	Tornado Warning	OAX	35 min
Jul 19, 10:19 PM CDT	Severe Thunderstorm Warning	OAX	41 min
Jul 20, 10:04 AM CDT	Mesoscale Discussion	SPC	86 min
Jul 20, 8:58 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 23, 10:45 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 24, 1:46 AM CDT	Mesoscale Discussion	SPC	89 min
Jul 26, 3:58 AM CDT	Dense Fog Advisory	OAX	5 hr
Jul 27, 2:29 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 28, 5:31 AM CDT	Mesoscale Discussion	SPC	89 min
Jul 28, 7:26 AM CDT	Mesoscale Discussion	SPC	94 min
Jul 30, 5:02 AM CDT	Dense Fog Advisory	OAX	4 hr
Aug 2, 3:41 AM CDT	Heat Advisory	OAX	63 hr
Aug 22, 4:54 PM CDT	Mesoscale Discussion	SPC	3 hr
Aug 27, 4:40 AM CDT	Mesoscale Discussion	SPC	95 min
Aug 27, 10:16 PM CDT	Mesoscale Discussion	SPC	119 min
Sep 6, 3:03 AM CDT	Dense Fog Advisory	OAX	6 hr
Sep 7, 3:33 AM CDT	Dense Fog Advisory	OAX	5 hr
Sep 23, 12:31 PM CDT	Mesoscale Discussion	SPC	119 min
Sep 23, 3:23 PM CDT	Severe Thunderstorm Warning	OAX	37 min
Sep 24, 6:44 AM CDT	Dense Fog Advisory	OAX	4 hr
Sep 24, 3:12 PM CDT	Dense Fog Advisory	OAX	12 hr
Oct 1, 3:31 PM CDT	Frost Advisory	OAX	16 hr
Oct 12, 3:43 AM CDT	Wind Advisory	OAX	12 hr
Oct 15, 3:28 PM CDT	Freeze Warning	OAX	18 hr
Oct 22, 3:47 PM CDT	Flood Watch	OAX	6 hr
Oct 26, 3:33 AM CDT	Wind Advisory	OAX	15 hr
Oct 26, 3:17 PM CDT	Freeze Warning	OAX	18 hr
Nov 5, 5:06 PM CST	Severe Thunderstorm Watch	SPC	4 hr
Nov 5, 7:08 PM CST	Mesoscale Discussion	SPC	97 min
Nov 6, 4:05 AM CST	Wind Advisory	OAX	36 hr
Nov 10, 7:01 PM CST	Freezing Rain Advisory	OAX	8 hr
Dec 7, 3:48 PM CST	Winter Storm Watch	OAX	21 hr
Dec 8, 12:40 PM CST	Winter Weather Advisory	OAX	21 hr
Dec 13, 4:25 PM CST	Wind Advisory	OAX	23 hr
Dec 14, 3:35 AM CST	Wind Chill Advisory	OAX	32 hr
Dec 15, 4:11 PM CST	Winter Weather Advisory	OAX	23 hr
Dec 17, 3:31 AM CST	Winter Storm Watch	OAX	24 hr
Dec 18, 3:52 AM CST	Winter Weather Advisory	OAX	17 hr
Dec 18, 11:58 AM CST	Winter Storm Warning	OAX	16 hr
Dec 18, 6:37 PM CST	Mesoscale Discussion	SPC	5 hr
Dec 18, 6:46 PM CST	Mesoscale Discussion	SPC	6 hr
Dec 19, 3:34 PM CST	Wind Chill Watch	OAX	24 hr
Dec 19, 3:34 PM CST	Winter Weather Advisory	OAX	28 hr
Dec 20, 3:35 PM CST	Wind Chill Warning	OAX	31 hr
Dec 30, 3:27 AM CST	Wind Advisory	OAX	15 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	25
Tornado Warning	7
Severe Thunderstorm Watch	19
Tornado Watch	8
Mesoscale Discussion	53
Flooding
Flash Flood Warning	1
Flash Flood Watch	4
Flood Watch	1
Winter
Winter Storm Warning	1
Winter Storm Watch	2
Blowing Snow Advisory	1
Freezing Rain Advisory	1
Snow Advisory	3
Snow and Blowing Snow Advisory	2
Winter Weather Advisory	9
Heat
Heat Advisory	1
Cold
Freeze Warning	2
Wind Chill Warning	2
Wind Chill Watch	1
Frost Advisory	1
Wind Chill Advisory	4
Wind and dust
Wind Advisory	12
Fog and smoke
Air Stagnation Advisory	1
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 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.