Alert archive / Illinois / Grundy County

Weather alerts in Grundy County, Illinois, 2013

147 weather alerts in 2013, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Grundy County and its neighbors

Each county as a circle sized by its count in 2013. Tap one for its archive.

Alerts: 147
Warnings: 35
Watches: 20
Advisories: 42
Busiest month: June38 alerts
Busiest day: April 18, 20139 alerts

Over time

By month

Warning verification

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

1 of 4 tornado warnings covering Grundy County in 2013 had a tornado report inside them; 2 of 3 tornado reports fell inside a warning, on average 7 minutes after it went out.

Grundy County, 2013

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	4	1	75%	3	67%	7 min
Severe thunderstorm warnings	16	10	38%	18	39%	38 min
Flash flood warnings	5	2	60%	0

Each office's whole area, 2013

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Chicago, IL: tornado warnings	17	6	65%	25	56%	13 min
NWS Chicago, IL: severe thunderstorm warnings	135	86	36%	425	79%	29 min
NWS Chicago, IL: flash flood warnings	32	12	63%	37	86%	123 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 12, 4:31 PM CST	Winter Weather Advisory	LOT	11 hr
Jan 12, 6:17 PM CST	Mesoscale Discussion	SPC	6 hr
Jan 19, 10:58 AM CST	Wind Advisory	LOT	16 hr
Jan 21, 3:57 AM CST	Wind Chill Advisory	LOT	30 hr
Jan 26, 4:21 AM CST	Winter Storm Watch	LOT	24 hr
Jan 26, 3:14 PM CST	Freezing Rain Advisory	LOT	30 hr
Jan 27, 11:48 AM CST	Mesoscale Discussion	SPC	4 hr
Jan 28, 3:28 PM CST	Flood Watch	LOT	37 hr
Jan 28, 3:54 PM CST	Dense Fog Advisory	LOT	11 hr
Jan 28, 9:59 PM CST	Mesoscale Discussion	SPC	2 hr
Jan 29, 1:25 PM CST	Special Weather Statement	LOT	35 min
Jan 29, 6:33 PM CST	Areal Flood Advisory	LOT	113 days
Jan 29, 7:37 PM CST	Areal Flood Advisory	LOT	6 hr
Jan 29, 10:33 PM CST	Areal Flood Advisory	LOT	10 hr
Feb 10, 7:30 PM CST	Wind Advisory	LOT	23 hr
Feb 20, 3:00 PM CST	Winter Weather Advisory	LOT	46 hr
Feb 21, 7:46 PM CST	Mesoscale Discussion	SPC	4 hr
Feb 24, 9:48 PM CST	Winter Storm Watch	LOT	29 hr
Feb 26, 2:30 AM CST	Winter Weather Advisory	LOT	25 hr
Mar 3, 3:11 PM CST	Winter Storm Watch	LOT	20 hr
Mar 4, 4:06 AM CST	Winter Storm Warning	LOT	47 hr
Mar 10, 12:34 PM CDT	River Flood Advisory	LOT	23 hr
Mar 10, 4:15 PM CDT	Areal Flood Advisory	LOT	22 hr
Mar 11, 7:51 AM CDT	River Flood Advisory	LOT	15 hr
Mar 11, 11:30 AM CDT	River Flood Warning	LOT	11 hr
Mar 18, 5:17 AM CDT	Winter Weather Advisory	LOT	6 hr
Apr 6, 10:44 PM CDT	Special Weather Statement	LOT	61 min
Apr 14, 4:10 AM CDT	Wind Advisory	LOT	15 hr
Apr 16, 4:31 PM CDT	Flood Watch	LOT	59 hr
Apr 17, 8:49 AM CDT	Mesoscale Discussion	SPC	56 min
Apr 17, 9:14 AM CDT	Severe Thunderstorm Watch	SPC	10 hr
Apr 17, 12:25 PM CDT	River Flood Advisory	LOT	10 hr
Apr 17, 1:33 PM CDT	Mesoscale Discussion	SPC	57 min
Apr 17, 2:11 PM CDT	Special Weather Statement	LOT	64 min
Apr 17, 3:04 PM CDT	Mesoscale Discussion	SPC	56 min
Apr 17, 3:14 PM CDT	Special Weather Statement	LOT	31 min
Apr 17, 6:12 PM CDT	Areal Flood Warning	LOT	18 hr
Apr 17, 7:44 PM CDT	Flash Flood Warning	LOT	8 hr
Apr 17, 9:03 PM CDT	River Flood Warning	LOT	56 hr
Apr 17, 10:31 PM CDT	River Flood Warning	LOT	7 days
Apr 17, 10:31 PM CDT	River Flood Warning	LOT	53 hr
Apr 18, 2:15 AM CDT	Areal Flood Warning	LOT	10 hr
Apr 18, 4:05 AM CDT	Flash Flood Warning Emergency	LOT	8 hr
Apr 18, 5:58 AM CDT	Flash Flood Warning	LOT	8 hr
Apr 18, 6:14 AM CDT	Special Weather Statement	LOT	61 min
Apr 18, 12:00 PM CDT	Flash Flood Warning	LOT	8 hr
Apr 18, 7:36 PM CDT	Areal Flood Warning	LOT	36 hr
May 12, 4:07 AM CDT	Frost Advisory	LOT	27 hr
May 20, 7:17 PM CDT	Mesoscale Discussion	SPC	58 min
May 20, 7:48 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
May 20, 8:55 PM CDT	Severe Thunderstorm Warning	LOT	35 min
May 20, 9:12 PM CDT	Severe Thunderstorm Warning	LOT	78 min
May 20, 10:54 PM CDT	Severe Thunderstorm Warning	LOT	66 min
May 27, 1:54 PM CDT	Flash Flood Watch	LOT	40 hr
May 28, 7:58 PM CDT	Severe Thunderstorm Warning	LOT	47 min
May 28, 8:23 PM CDT	Tornado Warning	LOT	37 min
May 28, 11:35 PM CDT	River Flood Advisory	LOT	16 hr
May 30, 4:09 AM CDT	Flash Flood Watch	LOT	66 hr
May 30, 2:55 PM CDT	Severe Thunderstorm Warning	LOT	65 min
May 30, 3:34 PM CDT	Severe Thunderstorm Warning	LOT	56 min
May 30, 4:16 PM CDT	Severe Thunderstorm Warning	LOT	59 min
May 30, 5:48 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
May 31, 10:37 AM CDT	River Flood Advisory	LOT	12 hr
May 31, 10:37 AM CDT	River Flood Advisory	LOT	12 hr
May 31, 12:40 PM CDT	River Flood Watch	LOT	11 hr
May 31, 11:51 PM CDT	River Flood Advisory	LOT	13 hr
Jun 1, 9:04 PM CDT	River Flood Advisory	LOT	37 hr
Jun 2, 3:58 AM CDT	River Flood Advisory	LOT	7 hr
Jun 12, 10:26 AM CDT	Mesoscale Discussion	SPC	64 min
Jun 12, 1:49 PM CDT	Tornado Watch PDS	SPC	9 hr
Jun 12, 3:38 PM CDT	Mesoscale Discussion	SPC	97 min
Jun 12, 4:06 PM CDT	Mesoscale Discussion	SPC	54 min
Jun 12, 5:38 PM CDT	Severe Thunderstorm Warning	LOT	67 min
Jun 12, 5:56 PM CDT	Mesoscale Discussion	SPC	94 min
Jun 12, 6:08 PM CDT	Flash Flood Warning	LOT	3 hr
Jun 12, 6:40 PM CDT	Mesoscale Discussion	SPC	95 min
Jun 12, 11:50 PM CDT	Mesoscale Discussion	SPC	85 min
Jun 21, 8:07 AM CDT	Mesoscale Discussion	SPC	53 min
Jun 21, 8:38 AM CDT	Severe Thunderstorm Watch	SPC	4 hr
Jun 21, 10:12 AM CDT	Mesoscale Discussion	SPC	2 hr
Jun 21, 12:32 PM CDT	Special Weather Statement	LOT	58 min
Jun 21, 1:12 PM CDT	Areal Flood Advisory	LOT	4 hr
Jun 23, 2:26 PM CDT	Mesoscale Discussion	SPC	94 min
Jun 23, 4:36 PM CDT	Special Weather Statement	LOT	54 min
Jun 23, 4:46 PM CDT	Severe Thunderstorm Warning	LOT	29 min
Jun 23, 6:09 PM CDT	Special Weather Statement	LOT	36 min
Jun 24, 3:37 AM CDT	Flash Flood Watch	LOT	60 hr
Jun 24, 2:11 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 24, 3:14 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 24, 4:47 PM CDT	Severe Thunderstorm Warning	LOT	58 min
Jun 24, 4:51 PM CDT	Severe Thunderstorm Warning	LOT	54 min
Jun 24, 5:36 PM CDT	Severe Thunderstorm Warning	LOT	84 min
Jun 24, 6:00 PM CDT	Mesoscale Discussion	SPC	75 min
Jun 25, 12:43 PM CDT	Mesoscale Discussion	SPC	3 hr
Jun 25, 3:06 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 25, 5:49 PM CDT	Mesoscale Discussion	SPC	56 min
Jun 25, 9:49 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 26, 3:32 AM CDT	Mesoscale Discussion	SPC	88 min
Jun 26, 8:34 AM CDT	Severe Thunderstorm Warning	LOT	26 min
Jun 28, 12:36 PM CDT	Mesoscale Discussion	SPC	54 min
Jun 28, 3:29 PM CDT	Special Weather Statement	LOT	46 min
Jun 28, 4:01 PM CDT	Special Weather Statement	LOT	29 min
Jun 29, 1:46 PM CDT	Areal Flood Advisory	LOT	4 hr
Jul 10, 7:56 AM CDT	Special Weather Statement	LOT	34 min
Jul 17, 3:29 PM CDT	Heat Advisory	LOT	52 hr
Aug 2, 2:24 PM CDT	Mesoscale Discussion	SPC	66 min
Aug 7, 7:52 AM CDT	Mesoscale Discussion	SPC	113 min
Aug 7, 1:46 PM CDT	Mesoscale Discussion	SPC	119 min
Aug 22, 11:45 AM CDT	Areal Flood Advisory	LOT	6 hr
Aug 23, 1:19 AM CDT	Dense Fog Advisory	LOT	8 hr
Aug 30, 2:07 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Aug 30, 5:14 PM CDT	Mesoscale Discussion	SPC	61 min
Aug 30, 6:38 PM CDT	Special Weather Statement	LOT	22 min
Aug 30, 7:10 PM CDT	Mesoscale Discussion	SPC	65 min
Aug 30, 8:32 PM CDT	Mesoscale Discussion	SPC	58 min
Sep 1, 4:27 AM CDT	Dense Fog Advisory	LOT	6 hr
Sep 1, 6:11 PM CDT	Mesoscale Discussion	SPC	2 hr
Sep 1, 6:20 PM CDT	Special Weather Statement	LOT	55 min
Sep 1, 6:44 PM CDT	Tornado Warning Tornado observed	LOT	46 min
Sep 7, 4:01 PM CDT	Mesoscale Discussion	SPC	119 min
Sep 18, 3:17 PM CDT	Severe Thunderstorm Warning	LOT	43 min
Sep 18, 3:51 PM CDT	Special Weather Statement	LOT	54 min
Oct 2, 4:45 AM CDT	Dense Fog Advisory	LOT	5 hr
Oct 3, 7:26 AM CDT	Dense Fog Advisory	LOT	3 hr
Oct 3, 5:08 PM CDT	Mesoscale Discussion	SPC	97 min
Oct 5, 12:29 PM CDT	Mesoscale Discussion	SPC	2 hr
Oct 13, 3:07 PM CDT	Frost Advisory	LOT	17 hr
Oct 21, 3:47 AM CDT	Freeze Watch	LOT	12 hr
Oct 21, 3:21 PM CDT	Freeze Warning	LOT	17 hr
Oct 30, 5:45 AM CDT	Dense Fog Advisory	LOT	5 hr
Nov 16, 2:59 PM CST	Wind Advisory	LOT	29 hr
Nov 17, 3:09 AM CST	High Wind Warning	LOT	17 hr
Nov 17, 7:47 AM CST	Mesoscale Discussion	SPC	88 min
Nov 17, 8:40 AM CST	Tornado Watch PDS	SPC	7 hr
Nov 17, 10:49 AM CST	Mesoscale Discussion	SPC	86 min
Nov 17, 11:07 AM CST	Severe Thunderstorm Warning	LOT	23 min
Nov 17, 11:33 AM CST	Tornado Warning Tornado observed	LOT	42 min
Nov 17, 11:57 AM CST	Mesoscale Discussion	SPC	93 min
Nov 17, 12:14 PM CST	Tornado Warning	LOT	46 min
Nov 17, 1:02 PM CST	Severe Thunderstorm Warning	LOT	43 min
Dec 3, 6:50 AM CST	Dense Fog Advisory	LOT	6 hr
Dec 10, 3:46 AM CST	Winter Weather Advisory	LOT	30 hr
Dec 11, 3:46 AM CST	Wind Chill Advisory	LOT	25 hr
Dec 12, 7:50 PM CST	Winter Weather Advisory	LOT	46 hr
Dec 21, 2:20 AM CST	Winter Weather Advisory	LOT	32 hr
Dec 29, 4:00 AM CST	Wind Chill Advisory	LOT	29 hr
Dec 29, 9:38 AM CST	Freezing Rain Advisory	LOT	8 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	16
Tornado Warning	4
Severe Thunderstorm Watch	8
Tornado Watch	2
Mesoscale Discussion	36
Special Weather Statement	14
Flooding
Areal Flood Warning	3
Flash Flood Warning	5
River Flood Warning	4
Flash Flood Watch	3
Flood Watch	2
River Flood Watch	1
Areal Flood Advisory	7
River Flood Advisory	9
Winter
Winter Storm Warning	1
Winter Storm Watch	3
Freezing Rain Advisory	2
Winter Weather Advisory	7
Heat
Heat Advisory	1
Cold
Freeze Warning	1
Freeze Watch	1
Frost Advisory	2
Wind Chill Advisory	3
Wind and dust
High Wind Warning	1
Wind Advisory	4
Fog and smoke
Dense Fog Advisory	7

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2012 2014

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.