Alert archive / Illinois / LaSalle County

Weather alerts in LaSalle County, Illinois, 2019

241 weather alerts in 2019, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

LaSalle County and its neighbors

Each county as a circle sized by its count in 2019. Tap one for its archive.

Alerts: 241
Warnings: 67
Watches: 28
Advisories: 97
Busiest month: May42 alerts
Busiest day: September 28, 201912 alerts

Over time

By month

Warning verification

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

2 of 3 tornado warnings covering LaSalle County in 2019 had a tornado report inside them; 1 of 1 tornado reports fell inside a warning, on average 17 minutes after it went out.

LaSalle County, 2019

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	3	2	33%	1	100%	17 min
Severe thunderstorm warnings	12	3	75%	10	20%	25 min
Flash flood warnings	4	1	75%	1	0%

Each office's whole area, 2019

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Chicago, IL: tornado warnings	18	3	83%	9	44%	17 min
NWS Chicago, IL: severe thunderstorm warnings	127	72	43%	281	75%	24 min
NWS Chicago, IL: flash flood warnings	23	9	61%	40	57%	110 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, 6:04 AM CST	Winter Weather Advisory	LOT	5 hr
Jan 7, 2:10 PM CST	Wind Advisory	LOT	33 hr
Jan 11, 3:15 AM CST	Winter Weather Advisory	LOT	48 hr
Jan 14, 1:45 PM CST	Winter Weather Advisory	LOT	16 hr
Jan 17, 12:13 PM CST	Winter Storm Watch	LOT	15 hr
Jan 18, 3:23 AM CST	Winter Storm Warning	LOT	35 hr
Jan 21, 1:57 PM CST	Winter Weather Advisory	LOT	46 hr
Jan 22, 2:36 PM CST	Mesoscale Discussion	SPC	4 hr
Jan 23, 2:20 PM CST	Wind Chill Watch	LOT	13 hr
Jan 23, 3:00 PM CST	Wind Chill Advisory	LOT	45 hr
Jan 26, 10:01 PM CST	Wind Chill Advisory	LOT	11 hr
Jan 27, 3:01 AM CST	Winter Weather Advisory	LOT	45 hr
Jan 28, 2:42 AM CST	Mesoscale Discussion	SPC	4 hr
Jan 28, 3:01 AM CST	Wind Chill Watch	LOT	11 hr
Jan 28, 1:36 PM CST	Wind Chill Warning	LOT	70 hr
Jan 28, 1:36 PM CST	Wind Chill Advisory	LOT	28 hr
Jan 31, 3:17 AM CST	Winter Weather Advisory	LOT	24 hr
Feb 2, 7:12 PM CST	Dense Fog Advisory	LOT	6 hr
Feb 3, 10:05 AM CST	River Flood Warning	LOT	17 days
Feb 3, 10:11 AM CST	River Flood Advisory	LOT	50 hr
Feb 3, 9:23 PM CST	River Flood Advisory	LOT	24 hr
Feb 4, 12:04 PM CST	River Flood Warning	LOT	48 hr
Feb 4, 2:05 PM CST	Winter Weather Advisory	LOT	34 hr
Feb 5, 3:31 AM CST	Ice Storm Warning	LOT	23 hr
Feb 5, 9:29 AM CST	Areal Flood Warning	LOT	3 hr
Feb 5, 11:53 AM CST	River Flood Warning	LOT	21 days
Feb 5, 5:56 PM CST	Mesoscale Discussion	SPC	6 hr
Feb 6, 2:55 AM CST	Winter Weather Advisory	LOT	30 hr
Feb 6, 2:55 AM CST	Winter Weather Advisory	LOT	6 hr
Feb 7, 9:21 AM CST	Dense Fog Advisory	LOT	5 hr
Feb 7, 10:09 AM CST	River Flood Warning	LOT	56 hr
Feb 7, 10:20 AM CST	River Flood Advisory	LOT	21 hr
Feb 7, 12:14 PM CST	Winter Weather Advisory	LOT	14 hr
Feb 8, 2:25 AM CST	Wind Chill Advisory	LOT	8 hr
Feb 8, 9:15 AM CST	River Flood Advisory	LOT	45 hr
Feb 10, 2:43 PM CST	Winter Weather Advisory	LOT	60 hr
Feb 11, 7:21 PM CST	Mesoscale Discussion	SPC	6 hr
Feb 11, 9:59 PM CST	Ice Storm Warning	LOT	11 hr
Feb 12, 3:44 AM CST	Wind Advisory	LOT	23 hr
Feb 12, 7:57 AM CST	Dense Fog Advisory	LOT	2 hr
Feb 12, 7:36 PM CST	River Flood Advisory	LOT	41 hr
Feb 15, 10:31 AM CST	River Flood Advisory	LOT	48 hr
Feb 16, 2:58 PM CST	Winter Weather Advisory	LOT	42 hr
Feb 19, 3:35 AM CST	Winter Weather Advisory	LOT	35 hr
Feb 22, 3:06 PM CST	High Wind Watch	LOT	23 hr
Feb 23, 2:07 PM CST	High Wind Warning	LOT	31 hr
Feb 23, 8:17 PM CST	River Flood Advisory	LOT	36 hr
Feb 23, 8:47 PM CST	River Flood Watch	LOT	9 hr
Feb 23, 8:55 PM CST	River Flood Advisory	LOT	4 days
Feb 24, 5:44 AM CST	River Flood Warning	LOT	5 days
Mar 3, 3:11 AM CST	Wind Chill Advisory	LOT	32 hr
Mar 5, 9:33 PM CST	River Flood Warning	LOT	4 days
Mar 9, 10:53 AM CST	River Flood Advisory	LOT	4 days
Mar 9, 2:29 PM CST	Wind Advisory	LOT	16 hr
Mar 9, 5:09 PM CST	Areal Flood Advisory	LOT	5 hr
Mar 9, 6:59 PM CST	Areal Flood Warning	LOT	3 hr
Mar 10, 11:42 AM CDT	River Flood Warning	LOT	35 hr
Mar 10, 11:44 AM CDT	River Flood Advisory	LOT	35 hr
Mar 11, 10:33 PM CDT	River Flood Advisory	LOT	6 days
Mar 13, 11:27 AM CDT	River Flood Warning	LOT	10 days
Mar 13, 11:29 AM CDT	River Flood Advisory	LOT	4 days
Mar 13, 2:42 PM CDT	Wind Advisory	LOT	31 hr
Mar 13, 8:10 PM CDT	River Flood Advisory	LOT	55 hr
Mar 14, 10:54 AM CDT	Mesoscale Discussion	SPC	96 min
Mar 14, 12:24 PM CDT	Tornado Watch	SPC	2 hr
Mar 14, 12:38 PM CDT	Special Weather Statement	LOT	52 min
Mar 29, 8:46 PM CDT	River Flood Watch	LOT	14 hr
Mar 30, 10:50 AM CDT	River Flood Warning	LOT	34 hr
Mar 30, 8:50 PM CDT	River Flood Advisory	LOT	25 hr
Mar 31, 9:14 PM CDT	River Flood Advisory	LOT	4 days
Apr 6, 5:03 AM CDT	Dense Fog Advisory	LOT	4 hr
Apr 7, 3:14 PM CDT	Mesoscale Discussion	SPC	3 hr
Apr 10, 2:52 PM CDT	Wind Advisory	LOT	27 hr
Apr 12, 3:23 AM CDT	Wind Advisory	LOT	17 hr
Apr 14, 8:27 AM CDT	Mesoscale Discussion	SPC	3 hr
Apr 14, 11:23 AM CDT	Winter Weather Advisory	LOT	4 hr
Apr 16, 11:04 AM CDT	River Flood Advisory	LOT	6 days
Apr 29, 9:08 AM CDT	River Flood Warning	LOT	5 days
Apr 29, 11:05 AM CDT	River Flood Warning	LOT	51 days
Apr 29, 11:09 AM CDT	River Flood Advisory	LOT	10 hr
Apr 29, 9:03 PM CDT	River Flood Warning	LOT	8 days
Apr 30, 1:04 PM CDT	Areal Flood Advisory	LOT	116 min
Apr 30, 2:22 PM CDT	Areal Flood Advisory	LOT	3 hr
Apr 30, 2:44 PM CDT	Flash Flood Watch	LOT	17 hr
Apr 30, 8:51 PM CDT	River Flood Warning	LOT	5 days
May 1, 2:14 PM CDT	Flash Flood Watch	LOT	27 hr
May 7, 11:24 AM CDT	River Flood Warning	LOT	4 days
May 8, 7:24 PM CDT	Special Weather Statement	LOT	36 min
May 8, 7:53 PM CDT	Special Weather Statement	LOT	37 min
May 8, 8:17 PM CDT	Tornado Warning	LOT	13 min
May 9, 4:47 AM CDT	River Flood Warning	LOT	59 hr
May 9, 11:13 AM CDT	River Flood Warning	LOT	50 hr
May 16, 11:43 AM CDT	Special Weather Statement	LOT	47 min
May 16, 11:45 AM CDT	Tornado Warning	LOT	45 min
May 16, 12:17 PM CDT	Special Weather Statement	LOT	43 min
May 16, 12:41 PM CDT	Severe Thunderstorm Warning	LOT	64 min
May 16, 2:36 PM CDT	River Flood Advisory	LOT	19 hr
May 16, 2:40 PM CDT	River Flood Advisory	LOT	4 days
May 16, 7:14 PM CDT	Mesoscale Discussion	SPC	2 hr
May 16, 7:57 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
May 16, 11:12 PM CDT	Mesoscale Discussion	SPC	2 hr
May 18, 7:37 PM CDT	River Flood Advisory	LOT	33 hr
May 21, 11:11 AM CDT	River Flood Advisory	LOT	24 hr
May 22, 5:43 AM CDT	River Flood Advisory	LOT	37 hr
May 22, 11:10 AM CDT	River Flood Warning	LOT	65 hr
May 22, 9:43 PM CDT	Mesoscale Discussion	SPC	92 min
May 24, 3:33 AM CDT	Flash Flood Watch	LOT	22 hr
May 24, 11:18 AM CDT	River Flood Warning	LOT	5 days
May 24, 11:31 AM CDT	River Flood Warning	LOT	24 hr
May 24, 6:23 PM CDT	Tornado Watch	SPC	4 hr
May 24, 8:57 PM CDT	Mesoscale Discussion	SPC	2 hr
May 26, 8:05 PM CDT	River Flood Advisory	LOT	13 hr
May 27, 9:22 AM CDT	River Flood Warning	LOT	5 days
May 27, 11:33 AM CDT	River Flood Warning	LOT	5 days
May 27, 12:50 PM CDT	Mesoscale Discussion	SPC	85 min
May 27, 1:18 PM CDT	Severe Thunderstorm Warning	LOT	42 min
May 27, 1:22 PM CDT	Tornado Watch	SPC	9 hr
May 27, 3:57 PM CDT	Mesoscale Discussion	SPC	93 min
May 27, 4:13 PM CDT	Tornado Warning	LOT	32 min
May 28, 4:01 AM CDT	Flash Flood Watch	LOT	24 hr
May 28, 8:48 PM CDT	Severe Thunderstorm Watch	SPC	4 hr
May 28, 9:28 PM CDT	Areal Flood Advisory	LOT	6 hr
May 29, 10:45 AM CDT	River Flood Advisory	LOT	10 hr
May 30, 7:54 PM CDT	River Flood Advisory	LOT	2 hr
May 30, 9:36 PM CDT	Areal Flood Advisory	LOT	3 hr
May 30, 10:13 PM CDT	River Flood Warning	LOT	46 hr
Jun 1, 5:21 PM CDT	Mesoscale Discussion	SPC	54 min
Jun 4, 8:41 PM CDT	River Flood Advisory	LOT	54 hr
Jun 4, 11:58 PM CDT	Special Weather Statement	LOT	47 min
Jun 5, 12:24 AM CDT	Severe Thunderstorm Warning	LOT	29 min
Jun 5, 4:18 AM CDT	Areal Flood Advisory	LOT	3 hr
Jun 5, 7:30 AM CDT	River Flood Advisory	LOT	36 hr
Jun 20, 11:53 AM CDT	River Flood Warning	LOT	18 days
Jun 20, 11:58 AM CDT	River Flood Advisory	LOT	51 hr
Jun 23, 4:20 AM CDT	Special Weather Statement	LOT	25 min
Jun 23, 4:44 AM CDT	Special Weather Statement	LOT	31 min
Jun 25, 1:10 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 27, 5:44 PM CDT	Special Weather Statement	LOT	61 min
Jun 27, 6:17 PM CDT	Mesoscale Discussion	SPC	118 min
Jun 27, 6:37 PM CDT	Special Weather Statement	LOT	53 min
Jun 29, 3:24 PM CDT	Special Weather Statement	LOT	36 min
Jun 29, 5:06 PM CDT	Special Weather Statement	LOT	24 min
Jun 30, 11:43 AM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 30, 1:38 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 30, 2:02 PM CDT	Severe Thunderstorm Warning	LOT	43 min
Jun 30, 2:28 PM CDT	Severe Thunderstorm Warning	LOT	51 min
Jun 30, 9:18 PM CDT	River Flood Advisory	LOT	24 hr
Jul 2, 2:31 PM CDT	Mesoscale Discussion	SPC	89 min
Jul 2, 9:29 PM CDT	Severe Thunderstorm Warning	LOT	46 min
Jul 2, 11:15 PM CDT	Severe Thunderstorm Warning	LOT	30 min
Jul 3, 6:41 AM CDT	River Flood Warning	LOT	8 hr
Jul 3, 6:51 AM CDT	River Flood Advisory	LOT	59 hr
Jul 5, 2:56 PM CDT	Areal Flood Advisory	LOT	3 hr
Jul 6, 2:14 PM CDT	Mesoscale Discussion	SPC	3 hr
Jul 6, 2:49 PM CDT	Special Weather Statement	LOT	41 min
Jul 6, 2:59 PM CDT	Severe Thunderstorm Warning	LOT	61 min
Jul 6, 3:47 PM CDT	Special Weather Statement	LOT	28 min
Jul 16, 2:30 PM CDT	Excessive Heat Watch	LOT	24 hr
Jul 17, 2:14 PM CDT	Excessive Heat Warning	LOT	3 days
Jul 18, 8:12 AM CDT	Areal Flood Advisory	LOT	3 hr
Jul 18, 8:33 AM CDT	Special Weather Statement	LOT	27 min
Jul 18, 9:07 AM CDT	Special Weather Statement	LOT	23 min
Jul 18, 11:23 AM CDT	Areal Flood Advisory	LOT	86 min
Jul 21, 10:15 AM CDT	Areal Flood Advisory	LOT	3 hr
Jul 21, 10:39 AM CDT	Flash Flood Warning	LOT	3 hr
Jul 21, 11:58 AM CDT	Areal Flood Advisory	LOT	3 hr
Aug 12, 3:46 PM CDT	Mesoscale Discussion	SPC	89 min
Aug 14, 6:32 AM CDT	Dense Fog Advisory	LOT	88 min
Aug 16, 7:11 PM CDT	Special Weather Statement	LOT	49 min
Aug 17, 8:00 AM CDT	Mesoscale Discussion	SPC	2 hr
Aug 18, 5:44 AM CDT	Mesoscale Discussion	SPC	91 min
Aug 18, 6:06 AM CDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 18, 7:40 AM CDT	Mesoscale Discussion	SPC	2 hr
Aug 20, 5:43 AM CDT	Mesoscale Discussion	SPC	92 min
Aug 20, 6:18 AM CDT	Severe Thunderstorm Watch	SPC	11 hr
Aug 20, 9:04 AM CDT	Mesoscale Discussion	SPC	86 min
Aug 20, 10:16 AM CDT	Special Weather Statement	LOT	59 min
Sep 2, 4:47 AM CDT	Dense Fog Advisory	LOT	3 hr
Sep 3, 9:00 AM CDT	Areal Flood Advisory	LOT	2 hr
Sep 3, 3:54 PM CDT	Mesoscale Discussion	SPC	2 hr
Sep 12, 6:04 PM CDT	Mesoscale Discussion	SPC	116 min
Sep 12, 6:40 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Sep 12, 10:58 PM CDT	Mesoscale Discussion	SPC	2 hr
Sep 13, 10:15 AM CDT	River Flood Advisory	LOT	57 hr
Sep 15, 9:27 AM CDT	River Flood Advisory	LOT	25 hr
Sep 15, 9:12 PM CDT	Dense Fog Advisory	LOT	13 hr
Sep 21, 3:35 AM CDT	Flash Flood Watch	LOT	41 hr
Sep 21, 8:43 PM CDT	River Flood Warning	LOT	3 days
Sep 22, 11:00 AM CDT	River Flood Advisory	LOT	56 hr
Sep 22, 11:00 AM CDT	River Flood Advisory	LOT	68 hr
Sep 23, 8:02 PM CDT	River Flood Advisory	LOT	29 hr
Sep 27, 1:08 PM CDT	Areal Flood Advisory	LOT	3 hr
Sep 27, 1:37 PM CDT	Flash Flood Warning	LOT	4 hr
Sep 27, 1:43 PM CDT	Flash Flood Watch	LOT	16 hr
Sep 27, 3:01 PM CDT	Mesoscale Discussion	SPC	119 min
Sep 27, 3:15 PM CDT	Severe Thunderstorm Warning	LOT	30 min
Sep 27, 4:00 PM CDT	Tornado Watch	SPC	7 hr
Sep 27, 4:04 PM CDT	Areal Flood Advisory	LOT	3 hr
Sep 27, 5:31 PM CDT	Areal Flood Advisory	LOT	116 min
Sep 27, 6:21 PM CDT	Mesoscale Discussion	SPC	114 min
Sep 27, 6:30 PM CDT	Severe Thunderstorm Warning	LOT	45 min
Sep 27, 7:05 PM CDT	Areal Flood Advisory	LOT	6 hr
Sep 27, 7:37 PM CDT	Flash Flood Warning	LOT	6 hr
Sep 27, 8:00 PM CDT	Severe Thunderstorm Warning	LOT	30 min
Sep 27, 9:02 PM CDT	Flash Flood Warning	LOT	6 hr
Sep 27, 9:04 PM CDT	River Flood Warning	LOT	3 days
Sep 27, 9:18 PM CDT	Mesoscale Discussion	SPC	117 min
Sep 27, 9:28 PM CDT	River Flood Warning	LOT	4 days
Sep 27, 9:28 PM CDT	River Flood Warning	LOT	12 days
Sep 28, 1:33 AM CDT	Areal Flood Warning	LOT	6 hr
Sep 28, 2:48 AM CDT	Areal Flood Warning	LOT	6 hr
Sep 28, 9:13 AM CDT	River Flood Warning	LOT	10 hr
Sep 28, 2:41 PM CDT	Flash Flood Watch	LOT	16 hr
Oct 2, 9:15 PM CDT	Flash Flood Watch	LOT	6 hr
Oct 3, 12:05 AM CDT	Areal Flood Advisory	LOT	4 hr
Oct 3, 9:43 AM CDT	River Flood Warning	LOT	69 hr
Oct 10, 3:03 PM CDT	Freeze Watch	LOT	13 hr
Oct 11, 3:36 AM CDT	Freeze Warning	LOT	29 hr
Oct 11, 11:15 AM CDT	River Flood Advisory	LOT	36 hr
Oct 13, 2:23 PM CDT	Frost Advisory	LOT	18 hr
Oct 21, 8:34 PM CDT	Wind Advisory	LOT	18 hr
Oct 26, 10:04 AM CDT	Flood Watch	LOT	16 hr
Oct 26, 11:10 AM CDT	River Flood Advisory	LOT	21 hr
Oct 26, 11:16 AM CDT	River Flood Advisory	LOT	23 hr
Oct 26, 11:18 AM CDT	River Flood Advisory	LOT	11 hr
Oct 26, 7:10 PM CDT	Areal Flood Advisory	LOT	96 min
Oct 26, 8:44 PM CDT	Areal Flood Warning	LOT	12 hr
Oct 26, 10:21 PM CDT	River Flood Warning	LOT	12 days
Oct 27, 8:35 AM CDT	River Flood Warning	LOT	26 hr
Oct 27, 10:34 AM CDT	River Flood Warning	LOT	48 hr
Oct 29, 2:55 PM CDT	Winter Weather Advisory	LOT	19 hr
Oct 30, 2:27 PM CDT	Winter Weather Advisory	LOT	28 hr
Oct 30, 9:05 PM CDT	River Flood Advisory	LOT	4 days
Oct 30, 10:08 PM CDT	River Flood Warning	LOT	55 hr
Oct 31, 1:24 PM CDT	River Flood Warning	LOT	7 hr
Nov 10, 12:55 PM CST	Winter Weather Advisory	LOT	32 hr
Nov 20, 4:42 AM CST	Dense Fog Advisory	LOT	6 hr
Nov 25, 2:44 PM CST	High Wind Watch	LOT	23 hr
Nov 26, 1:26 PM CST	High Wind Warning	LOT	29 hr
Nov 27, 1:03 AM CST	Severe Thunderstorm Warning	LOT	42 min
Dec 24, 1:36 AM CST	Freezing Fog 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	12
Tornado Warning	3
Severe Thunderstorm Watch	6
Tornado Watch	4
Mesoscale Discussion	31
Special Weather Statement	18
Flooding
Areal Flood Warning	5
Flash Flood Warning	4
River Flood Warning	35
Flash Flood Watch	8
Flood Watch	1
River Flood Watch	2
Areal Flood Advisory	18
River Flood Advisory	40
Winter
Ice Storm Warning	2
Winter Storm Warning	1
Winter Storm Watch	1
Winter Weather Advisory	17
Heat
Excessive Heat Warning	1
Excessive Heat Watch	1
Cold
Freeze Warning	1
Wind Chill Warning	1
Freeze Watch	1
Wind Chill Watch	2
Frost Advisory	1
Wind Chill Advisory	5
Wind and dust
High Wind Warning	2
High Wind Watch	2
Wind Advisory	7
Fog and smoke
Dense Fog Advisory	8
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 2018 2020

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.