Alert archive / Illinois / Iroquois County
Weather alerts in Iroquois County, Illinois, 2020
127 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Iroquois County and its neighbors
Each county as a circle sized by its count in 2020. Tap one for its archive.
- Alerts
- 127
- Warnings
- 29
- Watches
- 18
- Advisories
- 49
- Busiest month
- May27 alerts
- Busiest day
- June 27, 202013 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 2 tornado warnings covering Iroquois County in 2020 had a tornado report inside them; 0 of 1 tornado reports fell inside a warning.
Iroquois County, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 2 | 0 | 100% | 1 | 0% | |
| Severe thunderstorm warnings | 11 | 3 | 73% | 10 | 50% | 25 min |
| Flash flood warnings | 4 | 3 | 25% | 1 | 100% | 171 min |
Each office's whole area, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Chicago, IL: tornado warnings | 25 | 5 | 80% | 35 | 37% | 13 min |
| NWS Chicago, IL: severe thunderstorm warnings | 112 | 77 | 31% | 443 | 83% | 33 min |
| NWS Chicago, IL: flash flood warnings | 19 | 11 | 42% | 64 | 83% | 114 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 9, 3:20 AM CST | Wind Advisory | LOT | 15 hr |
| Jan 9, 3:39 AM CST | Flood Watch | LOT | 55 hr |
| Jan 9, 11:06 AM CST | River Flood Warning | LOT | 7 days |
| Jan 9, 11:06 AM CST | River Flood Warning | LOT | 70 hr |
| Jan 9, 11:07 AM CST | River Flood Warning | LOT | 4 days |
| Jan 12, 7:37 PM CST | Winter Weather Advisory | LOT | 7 hr |
| Jan 14, 8:49 PM CST | Dense Fog Advisory | LOT | 14 hr |
| Jan 16, 2:44 PM CST | Winter Weather Advisory | LOT | 51 hr |
| Jan 24, 8:34 AM CST | Dense Fog Advisory | LOT | 11 hr |
| Feb 5, 2:23 AM CST | Winter Weather Advisory | LOT | 33 hr |
| Feb 8, 1:38 PM CST | Winter Weather Advisory | LOT | 26 hr |
| Feb 11, 2:38 PM CST | Winter Weather Advisory | LOT | 52 hr |
| Feb 13, 2:07 PM CST | Wind Chill Advisory | LOT | 20 hr |
| Feb 17, 8:24 PM CST | Dense Fog Advisory | LOT | 6 hr |
| Feb 18, 9:38 AM CST | River Flood Advisory | LOT | 23 hr |
| Feb 25, 3:34 AM CST | Winter Weather Advisory | LOT | 38 hr |
| Mar 5, 2:10 PM CST | Wind Advisory | LOT | 22 hr |
| Mar 9, 2:49 AM CDT | Wind Advisory | LOT | 16 hr |
| Mar 14, 11:01 AM CDT | Mesoscale Discussion | SPC | 119 min |
| Mar 19, 8:51 AM CDT | River Flood Advisory | LOT | 43 hr |
| Mar 25, 4:39 AM CDT | Dense Fog Advisory | LOT | 6 hr |
| Mar 27, 8:24 AM CDT | River Flood Watch | LOT | 6 days |
| Mar 27, 8:24 AM CDT | River Flood Watch | LOT | 4 days |
| Mar 28, 9:15 AM CDT | River Flood Advisory | LOT | 16 hr |
| Mar 28, 10:18 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Mar 28, 2:43 PM CDT | Wind Advisory | LOT | 29 hr |
| Mar 28, 2:45 PM CDT | Tornado Watch | SPC | 6 hr |
| Mar 28, 8:41 PM CDT | Tornado Watch | SPC | 3 hr |
| Apr 8, 3:08 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Apr 9, 3:18 AM CDT | Wind Advisory | LOT | 16 hr |
| Apr 12, 3:57 AM CDT | Wind Advisory | LOT | 36 hr |
| Apr 16, 3:28 AM CDT | Winter Weather Advisory | LOT | 32 hr |
| Apr 29, 1:51 PM CDT | River Flood Advisory | LOT | 61 hr |
| Apr 29, 8:48 PM CDT | Areal Flood Advisory | LOT | 7 hr |
| May 7, 3:33 AM CDT | Freeze Watch | LOT | 24 hr |
| May 8, 3:56 AM CDT | Freeze Warning | LOT | 27 hr |
| May 14, 9:58 AM CDT | Special Weather Statement | LOT | 47 min |
| May 14, 3:11 PM CDT | River Flood Advisory | LOT | 3 days |
| May 14, 8:32 PM CDT | Areal Flood Advisory | LOT | 4 hr |
| May 14, 10:58 PM CDT | Areal Flood Advisory | LOT | 5 hr |
| May 15, 1:06 AM CDT | Mesoscale Discussion | SPC | 114 min |
| May 16, 2:47 PM CDT | Flash Flood Watch | LOT | 32 hr |
| May 16, 7:51 PM CDT | River Flood Advisory | LOT | 17 hr |
| May 17, 12:42 PM CDT | River Flood Warning | LOT | 5 days |
| May 17, 1:15 PM CDT | River Flood Watch | LOT | 6 days |
| May 17, 1:15 PM CDT | River Flood Watch | LOT | 5 days |
| May 17, 1:44 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| May 17, 2:14 PM CDT | Areal Flood Advisory | LOT | 3 hr |
| May 17, 4:32 PM CDT | Flash Flood Warning | LOT | 6 hr |
| May 17, 5:43 PM CDT | Areal Flood Advisory | LOT | 3 hr |
| May 17, 10:10 PM CDT | Areal Flood Warning | LOT | 30 hr |
| May 18, 11:59 AM CDT | Mesoscale Discussion | SPC | 91 min |
| May 18, 3:12 PM CDT | River Flood Advisory | LOT | 52 hr |
| May 18, 3:19 PM CDT | River Flood Warning | LOT | 21 hr |
| May 19, 11:30 AM CDT | River Flood Advisory | LOT | 41 hr |
| May 23, 12:33 PM CDT | Tornado Watch | SPC | 8 hr |
| May 23, 2:51 PM CDT | Mesoscale Discussion | SPC | 84 min |
| May 23, 3:27 PM CDT | Severe Thunderstorm Warning | LOT | 48 min |
| May 23, 3:50 PM CDT | Tornado Warning | LOT | 17 min |
| May 23, 4:09 PM CDT | Severe Thunderstorm Warning | LOT | 36 min |
| May 23, 4:13 PM CDT | Severe Thunderstorm Warning | LOT | 62 min |
| Jun 9, 2:33 AM CDT | Wind Advisory | LOT | 21 hr |
| Jun 9, 6:20 PM CDT | Mesoscale Discussion | SPC | 115 min |
| Jun 10, 9:00 AM CDT | Special Weather Statement | LOT | 30 min |
| Jun 22, 12:48 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 22, 1:36 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 22, 3:38 PM CDT | Mesoscale Discussion | SPC | 97 min |
| Jun 22, 6:00 PM CDT | Areal Flood Advisory | LOT | 3 hr |
| Jun 22, 6:24 PM CDT | Flash Flood Warning | LOT | 3 hr |
| Jun 26, 9:40 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Jun 26, 10:37 PM CDT | Areal Flood Advisory | LOT | 3 hr |
| Jun 27, 12:52 AM CDT | Special Weather Statement | LOT | 38 min |
| Jun 27, 3:02 AM CDT | Special Weather Statement | LOT | 28 min |
| Jun 27, 3:41 AM CDT | Special Weather Statement | LOT | 34 min |
| Jun 27, 3:44 AM CDT | Severe Thunderstorm Warning | LOT | 28 min |
| Jun 27, 4:50 AM CDT | Special Weather Statement | LOT | 55 min |
| Jun 27, 5:37 AM CDT | Areal Flood Advisory | LOT | 3 hr |
| Jun 27, 3:32 PM CDT | Flash Flood Warning | LOT | 4 hr |
| Jun 27, 4:12 PM CDT | Special Weather Statement | LOT | 33 min |
| Jun 27, 4:29 PM CDT | Flash Flood Warning | LOT | 3 hr |
| Jun 27, 4:34 PM CDT | Severe Thunderstorm Warning | LOT | 41 min |
| Jun 27, 6:10 PM CDT | Areal Flood Advisory | LOT | 2 hr |
| Jun 27, 7:30 PM CDT | Areal Flood Warning | LOT | 12 hr |
| Jun 27, 8:22 PM CDT | River Flood Warning | LOT | 4 days |
| Jun 27, 9:07 PM CDT | Areal Flood Advisory | LOT | 3 hr |
| Jun 28, 7:56 PM CDT | River Flood Advisory | LOT | 25 hr |
| Jul 11, 12:54 PM CDT | Severe Thunderstorm Warning | LOT | 66 min |
| Jul 11, 1:44 PM CDT | Severe Thunderstorm Warning | LOT | 61 min |
| Jul 11, 2:55 PM CDT | Severe Thunderstorm Warning | LOT | 50 min |
| Jul 11, 7:17 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Jul 11, 9:45 PM CDT | Special Weather Statement | LOT | 15 min |
| Jul 11, 10:08 PM CDT | Severe Thunderstorm Warning | LOT | 67 min |
| Jul 15, 3:14 PM CDT | Tornado Watch | SPC | 6 hr |
| Jul 15, 5:11 PM CDT | Tornado Warning | LOT | 45 min |
| Jul 15, 5:24 PM CDT | Areal Flood Advisory | LOT | 3 hr |
| Jul 15, 5:35 PM CDT | Mesoscale Discussion | SPC | 85 min |
| Jul 17, 3:36 AM CDT | Heat Advisory | LOT | 40 hr |
| Jul 19, 10:12 AM CDT | Mesoscale Discussion | SPC | 93 min |
| Jul 19, 10:32 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 19, 11:42 AM CDT | Special Weather Statement | LOT | 33 min |
| Jul 19, 12:19 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Jul 21, 11:19 AM CDT | Mesoscale Discussion | SPC | 86 min |
| Aug 10, 10:42 AM CDT | Mesoscale Discussion | SPC | 93 min |
| Aug 10, 11:26 AM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 10, 3:25 PM CDT | Severe Thunderstorm Warning | LOT | 65 min |
| Aug 10, 3:36 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Aug 15, 4:40 PM CDT | Mesoscale Discussion | SPC | 95 min |
| Aug 28, 12:32 PM CDT | Mesoscale Discussion | SPC | 88 min |
| Aug 29, 12:30 AM CDT | Special Weather Statement | LOT | 30 min |
| Aug 29, 12:35 AM CDT | Severe Thunderstorm Warning | LOT | 33 min |
| Oct 4, 3:46 AM CDT | Frost Advisory | LOT | 28 hr |
| Oct 14, 3:33 AM CDT | Wind Advisory | LOT | 15 hr |
| Oct 14, 3:44 AM CDT | Red Flag Warning | LOT | 15 hr |
| Oct 14, 7:41 PM CDT | Freeze Watch | LOT | 7 hr |
| Oct 15, 2:35 AM CDT | Freeze Warning | LOT | 30 hr |
| Oct 16, 3:52 AM CDT | Fire Weather Watch | LOT | 11 hr |
| Oct 16, 2:40 PM CDT | Wind Advisory | LOT | 28 hr |
| Oct 16, 2:52 PM CDT | Red Flag Warning | LOT | 29 hr |
| Oct 22, 3:30 AM CDT | Dense Fog Advisory | LOT | 9 hr |
| Oct 31, 10:44 AM CDT | Wind Advisory | LOT | 30 hr |
| Nov 10, 2:58 AM CST | Wind Advisory | LOT | 24 hr |
| Nov 10, 2:05 PM CST | Tornado Watch | SPC | 6 hr |
| Nov 10, 5:03 PM CST | Mesoscale Discussion | SPC | 57 min |
| Nov 10, 6:34 PM CST | Special Weather Statement | LOT | 41 min |
| Nov 14, 3:04 AM CST | Wind Advisory | LOT | 41 hr |
| Nov 18, 2:15 PM CST | Wind Advisory | LOT | 26 hr |
| Dec 23, 2:32 AM CST | Wind Advisory | LOT | 25 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 | 11 |
| Tornado Warning | 2 |
| Severe Thunderstorm Watch | 4 |
| Tornado Watch | 5 |
| Mesoscale Discussion | 20 |
| Special Weather Statement | 11 |
| Flooding | |
| Areal Flood Warning | 2 |
| Flash Flood Warning | 4 |
| River Flood Warning | 6 |
| Flash Flood Watch | 1 |
| Flood Watch | 1 |
| River Flood Watch | 4 |
| Areal Flood Advisory | 11 |
| River Flood Advisory | 9 |
| Winter | |
| Winter Weather Advisory | 7 |
| Heat | |
| Heat Advisory | 1 |
| Cold | |
| Freeze Warning | 2 |
| Freeze Watch | 2 |
| Frost Advisory | 1 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| Wind Advisory | 14 |
| Fire | |
| Red Flag Warning | 2 |
| Fire Weather Watch | 1 |
| Fog and smoke | |
| Dense Fog Advisory | 5 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20192021
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.