Alert archive / Illinois / Stephenson County

Weather alerts in Stephenson County, Illinois, 2018

150 weather alerts in 2018, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Stephenson County and its neighbors

Each county as a circle sized by its count in 2018. Tap one for its archive.

Alerts: 150
Warnings: 26
Watches: 22
Advisories: 43
Busiest month: June20 alerts
Busiest day: February 20, 20184 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 1 tornado warnings covering Stephenson County in 2018 had a tornado report inside them.

Stephenson County, 2018

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	1	0	100%	0
Severe thunderstorm warnings	6	6	0%	7	57%	20 min
Flash flood warnings	3	1	67%	2	50%	49 min

Each office's whole area, 2018

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Quad Cities, IA: tornado warnings	47	14	70%	32	59%	8 min
NWS Quad Cities, IA: severe thunderstorm warnings	136	92	32%	249	75%	22 min
NWS Quad Cities, IA: flash flood warnings	29	19	34%	39	79%	73 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, 2:50 PM CST	Wind Chill Advisory	DVN	43 hr
Jan 2, 9:18 PM CST	Special Weather Statement	DVN	117 min
Jan 2, 11:20 PM CST	Special Weather Statement	DVN	115 min
Jan 3, 1:25 AM CST	Special Weather Statement	DVN	2 hr
Jan 4, 3:09 PM CST	Wind Chill Advisory	DVN	19 hr
Jan 6, 2:50 AM CST	Wind Chill Advisory	DVN	6 hr
Jan 10, 2:57 PM CST	Dense Fog Advisory	DVN	8 hr
Jan 11, 3:07 AM CST	Winter Weather Advisory	DVN	17 hr
Jan 11, 12:00 PM CST	Special Weather Statement	DVN	2 hr
Jan 14, 2:45 PM CST	Winter Weather Advisory	DVN	21 hr
Jan 14, 4:36 PM CST	Special Weather Statement	DVN	84 min
Jan 14, 6:03 PM CST	Special Weather Statement	DVN	57 min
Jan 15, 12:09 PM CST	Winter Weather Advisory	DVN	3 hr
Jan 21, 4:01 PM CST	Dense Fog Advisory	DVN	14 hr
Jan 22, 11:07 AM CST	Areal Flood Advisory	DVN	24 hr
Jan 22, 3:18 PM CST	Special Weather Statement	DVN	27 min
Feb 4, 1:53 PM CST	Winter Weather Advisory	DVN	32 hr
Feb 7, 1:54 PM CST	Winter Storm Watch	DVN	13 hr
Feb 8, 2:59 AM CST	Winter Storm Warning	DVN	30 hr
Feb 8, 9:07 PM CST	Mesoscale Discussion	SPC	6 hr
Feb 9, 3:08 AM CST	Mesoscale Discussion	SPC	6 hr
Feb 10, 3:14 PM CST	Winter Weather Advisory	DVN	18 hr
Feb 14, 5:42 PM CST	Dense Fog Advisory	DVN	20 hr
Feb 18, 2:28 AM CST	Dense Fog Advisory	DVN	8 hr
Feb 19, 1:39 PM CST	Dense Fog Advisory	DVN	13 hr
Feb 20, 9:37 AM CST	Flood Watch	DVN	6 hr
Feb 20, 10:22 AM CST	Areal Flood Warning	DVN	24 hr
Feb 20, 10:23 AM CST	River Flood Watch	DVN	8 days
Feb 20, 3:19 PM CST	River Flood Warning	DVN	11 days
Feb 21, 10:14 AM CST	Areal Flood Warning	DVN	24 hr
Feb 22, 11:04 AM CST	Areal Flood Warning	DVN	24 hr
Mar 4, 3:32 PM CST	Winter Weather Advisory	DVN	32 hr
Mar 5, 6:50 AM CST	Winter Weather Advisory	DVN	17 hr
Mar 5, 7:10 AM CST	Special Weather Statement	DVN	95 min
Mar 16, 3:10 AM CDT	Winter Weather Advisory	DVN	32 hr
Mar 16, 9:33 PM CDT	Special Weather Statement	DVN	57 min
Mar 16, 10:36 PM CDT	Special Weather Statement	DVN	54 min
Mar 16, 11:31 PM CDT	Special Weather Statement	DVN	59 min
Mar 22, 3:45 AM CDT	Winter Storm Watch	DVN	24 hr
Mar 23, 3:30 AM CDT	Winter Weather Advisory	DVN	40 hr
Mar 23, 9:27 PM CDT	Winter Weather Advisory	DVN	17 hr
Mar 31, 6:13 AM CDT	Wind Advisory	DVN	10 hr
Apr 2, 3:10 PM CDT	Winter Weather Advisory	DVN	28 hr
Apr 5, 11:47 AM CDT	Special Weather Statement	DVN	58 min
Apr 5, 12:53 PM CDT	Special Weather Statement	DVN	112 min
Apr 5, 3:04 PM CDT	Special Weather Statement	DVN	86 min
Apr 13, 5:51 PM CDT	Wind Advisory	DVN	25 hr
Apr 14, 3:51 AM CDT	Winter Weather Advisory	DVN	39 hr
Apr 17, 4:07 AM CDT	Winter Weather Advisory	DVN	45 hr
Apr 27, 2:50 PM CDT	Red Flag Warning	DVN	5 hr
May 2, 1:33 PM CDT	Mesoscale Discussion	SPC	117 min
May 2, 3:56 PM CDT	Severe Thunderstorm Watch	SPC	9 hr
May 2, 5:04 PM CDT	Severe Thunderstorm Warning	DVN	56 min
May 2, 5:19 PM CDT	Severe Thunderstorm Warning	DVN	27 min
May 9, 1:49 PM CDT	Mesoscale Discussion	SPC	116 min
May 9, 3:45 PM CDT	Special Weather Statement	DVN	30 min
May 14, 2:40 AM CDT	Mesoscale Discussion	SPC	2 hr
May 14, 4:22 AM CDT	Special Weather Statement	DVN	38 min
May 22, 3:34 AM CDT	Dense Fog Advisory	DVN	5 hr
May 29, 4:04 PM CDT	Special Weather Statement	DVN	56 min
May 30, 8:22 AM CDT	Special Weather Statement	DVN	83 min
Jun 8, 7:29 PM CDT	Special Weather Statement	DVN	61 min
Jun 9, 3:01 PM CDT	Flash Flood Watch	DVN	16 hr
Jun 9, 6:30 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 9, 7:43 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 9, 10:17 PM CDT	Mesoscale Discussion	SPC	118 min
Jun 9, 11:44 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 15, 3:25 AM CDT	Heat Advisory	DVN	4 days
Jun 18, 5:33 PM CDT	Special Weather Statement	DVN	57 min
Jun 18, 6:18 PM CDT	Special Weather Statement	DVN	42 min
Jun 18, 6:52 PM CDT	Special Weather Statement	DVN	38 min
Jun 18, 7:41 PM CDT	Flash Flood Warning	DVN	6 hr
Jun 19, 6:39 AM CDT	Special Weather Statement	DVN	66 min
Jun 20, 11:52 AM CDT	Special Weather Statement	DVN	3 hr
Jun 20, 8:57 PM CDT	River Flood Watch	DVN	24 hr
Jun 21, 3:47 AM CDT	Flash Flood Watch	DVN	23 hr
Jun 26, 3:18 AM CDT	Flash Flood Watch	DVN	18 hr
Jun 26, 12:25 PM CDT	Special Weather Statement	DVN	65 min
Jun 26, 1:31 PM CDT	Mesoscale Discussion	SPC	89 min
Jun 27, 3:11 PM CDT	Heat Advisory	DVN	24 hr
Jun 28, 3:31 PM CDT	Excessive Heat Warning	DVN	54 hr
Jun 30, 10:06 PM CDT	Flash Flood Watch	DVN	5 hr
Jul 1, 11:37 AM CDT	Mesoscale Discussion	SPC	83 min
Jul 1, 12:23 PM CDT	Mesoscale Discussion	SPC	97 min
Jul 3, 3:48 PM CDT	Heat Advisory	DVN	28 hr
Jul 13, 3:54 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 13, 6:15 PM CDT	Severe Thunderstorm Warning	DVN	60 min
Jul 13, 6:23 PM CDT	Mesoscale Discussion	SPC	2 hr
Jul 13, 6:55 PM CDT	Severe Thunderstorm Warning	DVN	65 min
Jul 19, 7:57 PM CDT	Severe Thunderstorm Warning	DVN	24 min
Aug 2, 12:02 AM CDT	Special Weather Statement	DVN	58 min
Aug 5, 5:44 PM CDT	Mesoscale Discussion	SPC	2 hr
Aug 5, 6:45 PM CDT	Severe Thunderstorm Warning	DVN	45 min
Aug 6, 12:01 AM CDT	Special Weather Statement	DVN	29 min
Aug 7, 7:18 PM CDT	Special Weather Statement	DVN	42 min
Aug 9, 2:55 PM CDT	Mesoscale Discussion	SPC	65 min
Aug 9, 6:35 PM CDT	Special Weather Statement	DVN	40 min
Aug 15, 4:28 PM CDT	Special Weather Statement	DVN	2 hr
Aug 16, 3:00 AM CDT	Dense Fog Advisory	DVN	6 hr
Aug 16, 7:55 PM CDT	Special Weather Statement	DVN	80 min
Aug 16, 8:27 PM CDT	Tornado Warning Tornado observed	DVN	18 min
Aug 20, 4:46 PM CDT	Mesoscale Discussion	SPC	119 min
Aug 26, 3:03 AM CDT	Dense Fog Advisory	DVN	5 hr
Aug 26, 3:03 AM CDT	Heat Advisory	DVN	64 hr
Aug 26, 7:51 PM CDT	Special Weather Statement	DVN	39 min
Aug 26, 8:27 PM CDT	Special Weather Statement	DVN	33 min
Aug 26, 11:14 PM CDT	Special Weather Statement	DVN	31 min
Aug 28, 9:08 AM CDT	Flash Flood Watch	DVN	20 hr
Aug 28, 5:06 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 28, 7:05 PM CDT	Mesoscale Discussion	SPC	55 min
Sep 1, 3:44 AM CDT	Flash Flood Watch	DVN	24 hr
Sep 1, 11:02 PM CDT	Special Weather Statement	DVN	43 min
Sep 2, 9:26 AM CDT	Flash Flood Watch	DVN	39 hr
Sep 2, 3:47 PM CDT	Mesoscale Discussion	SPC	118 min
Sep 2, 9:46 PM CDT	River Flood Warning	DVN	9 days
Sep 3, 1:20 PM CDT	Mesoscale Discussion	SPC	2 hr
Sep 4, 3:56 AM CDT	Flash Flood Watch	DVN	39 hr
Sep 20, 8:48 AM CDT	River Flood Warning	DVN	8 days
Sep 21, 1:11 AM CDT	Special Weather Statement	DVN	79 min
Sep 25, 1:07 PM CDT	Mesoscale Discussion	SPC	113 min
Sep 25, 1:36 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Sep 25, 3:39 PM CDT	Mesoscale Discussion	SPC	96 min
Sep 28, 3:41 AM CDT	Frost Advisory	DVN	28 hr
Oct 1, 3:23 PM CDT	River Flood Warning	DVN	25 days
Oct 3, 10:28 PM CDT	Special Weather Statement	DVN	47 min
Oct 4, 1:18 PM CDT	Flash Flood Watch	DVN	48 hr
Oct 6, 3:03 AM CDT	Flash Flood Warning	DVN	6 hr
Oct 6, 9:00 AM CDT	Areal Flood Warning	DVN	12 hr
Oct 7, 2:44 PM CDT	Flash Flood Watch	DVN	70 hr
Oct 9, 3:42 AM CDT	Flash Flood Watch	DVN	33 hr
Oct 9, 2:45 PM CDT	Mesoscale Discussion	SPC	2 hr
Oct 10, 9:05 AM CDT	Flash Flood Warning	DVN	3 hr
Oct 11, 3:40 AM CDT	Freeze Warning	DVN	28 hr
Oct 12, 2:42 PM CDT	Freeze Warning	DVN	18 hr
Oct 14, 3:21 PM CDT	Freeze Warning	DVN	18 hr
Oct 15, 3:14 AM CDT	Freeze Warning	DVN	30 hr
Oct 19, 7:36 PM CDT	Wind Advisory	DVN	20 hr
Oct 27, 2:31 PM CDT	Wind Advisory	DVN	26 hr
Oct 30, 2:55 PM CDT	Special Weather Statement	DVN	65 min
Nov 16, 2:15 PM CST	Winter Weather Advisory	DVN	18 hr
Nov 23, 3:29 AM CST	Winter Storm Watch	DVN	24 hr
Nov 24, 3:52 AM CST	Winter Storm Warning	DVN	44 hr
Nov 30, 3:37 AM CST	Dense Fog Advisory	DVN	6 hr
Dec 1, 7:28 AM CST	Wind Advisory	DVN	7 hr
Dec 10, 12:42 AM CST	Dense Fog Advisory	DVN	9 hr
Dec 11, 12:08 PM CST	Winter Weather Advisory	DVN	21 hr
Dec 13, 11:58 PM CST	Dense Fog Advisory	DVN	9 hr
Dec 14, 3:57 PM CST	Dense Fog Advisory	DVN	11 hr
Dec 28, 2:37 PM CST	Winter Weather Advisory	DVN	7 hr
Dec 30, 3:03 PM CST	Winter Weather Advisory	DVN	21 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	6
Tornado Warning	1
Severe Thunderstorm Watch	5
Mesoscale Discussion	21
Special Weather Statement	38
Flooding
Areal Flood Warning	4
Flash Flood Warning	3
River Flood Warning	4
Flash Flood Watch	11
Flood Watch	1
River Flood Watch	2
Areal Flood Advisory	1
Winter
Winter Storm Warning	2
Winter Storm Watch	3
Winter Weather Advisory	17
Heat
Excessive Heat Warning	1
Heat Advisory	4
Cold
Freeze Warning	4
Frost Advisory	1
Wind Chill Advisory	3
Wind and dust
Wind Advisory	5
Fire
Red Flag Warning	1
Fog and smoke
Dense Fog Advisory	12

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2017 2019

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.