Alert archive / Missouri / Saint Charles County
Weather alerts in Saint Charles County, Missouri, 2017
114 weather alerts in 2017, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Saint Charles County and its neighbors
Each county as a circle sized by its count in 2017. Tap one for its archive.
- Alerts
- 114
- Warnings
- 43
- Watches
- 16
- Advisories
- 22
- Busiest month
- March17 alerts
- Busiest day
- April 29, 20176 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 4 tornado reports fell inside a warning.
Saint Charles County, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 4 | 0% | |||
| Severe thunderstorm warnings | 21 | 16 | 24% | 23 | 70% | 23 min |
| Flash flood warnings | 1 | 0 | 100% | 0 |
Each office's whole area, 2017
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS St. Louis, MO: tornado warnings | 22 | 9 | 59% | 26 | 54% | 11 min |
| NWS St. Louis, MO: severe thunderstorm warnings | 204 | 130 | 36% | 487 | 82% | 22 min |
| NWS St. Louis, MO: flash flood warnings | 20 | 9 | 55% | 33 | 97% | 302 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, 5:43 PM CST | Dense Fog Advisory | LSX | 13 hr |
| Jan 4, 3:24 AM CST | Winter Weather Advisory | LSX | 33 hr |
| Jan 10, 3:31 AM CST | Wind Advisory | LSX | 14 hr |
| Jan 11, 3:31 AM CST | Winter Storm Watch | LSX | 34 hr |
| Jan 12, 1:49 PM CST | Ice Storm Warning | LSX | 70 hr |
| Jan 13, 10:28 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Jan 14, 2:14 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Jan 15, 2:02 AM CST | Mesoscale Discussion | SPC | 5 hr |
| Jan 15, 10:41 PM CST | Dense Fog Advisory | LSX | 13 hr |
| Jan 19, 3:37 PM CST | Dense Fog Advisory | LSX | 20 hr |
| Feb 16, 3:37 AM CST | Red Flag Warning | LSX | 14 hr |
| Feb 19, 1:24 AM CST | Dense Fog Advisory | LSX | 10 hr |
| Feb 21, 10:42 PM CST | Dense Fog Advisory | LSX | 10 hr |
| Feb 23, 5:52 AM CST | Dense Fog Advisory | LSX | 3 hr |
| Feb 28, 2:19 PM CST | Tornado Watch | SPC | 7 hr |
| Feb 28, 9:04 PM CST | Tornado Watch | SPC | 7 hr |
| Mar 6, 3:33 PM CST | Fire Weather Watch | LSX | 12 hr |
| Mar 6, 8:22 PM CST | Mesoscale Discussion | SPC | 2 hr |
| Mar 6, 8:52 PM CST | Tornado Watch | SPC | 6 hr |
| Mar 6, 11:13 PM CST | Mesoscale Discussion | SPC | 2 hr |
| Mar 7, 12:08 AM CST | Severe Thunderstorm Warning | LSX | 52 min |
| Mar 7, 4:00 AM CST | Red Flag Warning | LSX | 15 hr |
| Mar 9, 3:35 PM CST | Freeze Warning | LSX | 68 hr |
| Mar 13, 2:04 PM CDT | Freeze Warning | LSX | 68 hr |
| Mar 24, 9:36 PM CDT | Mesoscale Discussion | SPC | 54 min |
| Mar 24, 11:25 PM CDT | Special Weather Statement | LSX | 50 min |
| Mar 24, 11:46 PM CDT | Special Weather Statement | LSX | 44 min |
| Mar 25, 12:39 AM CDT | Special Weather Statement | LSX | 81 min |
| Mar 29, 9:44 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Mar 30, 11:12 AM CDT | Special Weather Statement | LSX | 33 min |
| Mar 30, 11:25 AM CDT | Special Weather Statement | LSX | 35 min |
| Mar 30, 12:05 PM CDT | Severe Thunderstorm Warning | LSX | 40 min |
| Apr 5, 11:24 AM CDT | River Flood Warning | LSX | 11 days |
| Apr 5, 11:24 AM CDT | River Flood Warning | LSX | 7 days |
| Apr 5, 8:21 PM CDT | River Flood Warning | LSX | 5 days |
| Apr 10, 9:55 AM CDT | Special Weather Statement | LSX | 50 min |
| Apr 10, 9:58 AM CDT | Severe Thunderstorm Warning | LSX | 47 min |
| Apr 10, 10:29 AM CDT | Severe Thunderstorm Warning | LSX | 26 min |
| Apr 21, 8:59 AM CDT | River Flood Warning | LSX | 6 days |
| Apr 26, 9:51 PM CDT | River Flood Warning | LSX | 47 days |
| Apr 27, 4:29 AM CDT | Flash Flood Watch | LSX | 4 days |
| Apr 28, 1:10 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 28, 8:52 PM CDT | River Flood Warning | LSX | 69 hr |
| Apr 28, 9:23 PM CDT | River Flood Warning | LSX | 11 days |
| Apr 28, 10:18 PM CDT | River Flood Warning | LSX | 40 days |
| Apr 29, 2:47 PM CDT | Special Weather Statement | LSX | 58 min |
| Apr 29, 2:53 PM CDT | Severe Thunderstorm Warning | LSX | 52 min |
| Apr 29, 3:24 PM CDT | Severe Thunderstorm Warning | LSX | 51 min |
| Apr 30, 9:04 AM CDT | Areal Flood Warning | LSX | 12 hr |
| Apr 30, 9:01 PM CDT | Areal Flood Warning | LSX | 12 hr |
| May 1, 4:16 AM CDT | Flash Flood Warning | LSX | 6 hr |
| May 1, 8:59 AM CDT | Areal Flood Warning | LSX | 4 days |
| May 2, 4:07 AM CDT | Flash Flood Watch | LSX | 64 hr |
| May 3, 10:34 AM CDT | River Flood Warning | LSX | 64 hr |
| May 17, 3:20 AM CDT | Wind Advisory | LSX | 16 hr |
| May 19, 4:07 AM CDT | Mesoscale Discussion | SPC | 113 min |
| May 19, 4:16 AM CDT | Severe Thunderstorm Watch | SPC | 3 hr |
| May 19, 4:39 AM CDT | Severe Thunderstorm Warning | LSX | 66 min |
| May 19, 6:04 PM CDT | Mesoscale Discussion | SPC | 86 min |
| May 20, 8:43 PM CDT | River Flood Warning | LSX | 6 days |
| May 27, 1:36 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 27, 1:56 PM CDT | Severe Thunderstorm Warning | LSX | 23 min |
| May 27, 4:12 PM CDT | Severe Thunderstorm Warning | LSX | 34 min |
| May 29, 4:23 PM CDT | Special Weather Statement | LSX | 52 min |
| Jun 4, 5:09 PM CDT | Areal Flood Advisory | LSX | 3 hr |
| Jun 4, 5:49 PM CDT | Areal Flood Advisory | LSX | 3 hr |
| Jun 5, 5:24 AM CDT | Dense Fog Advisory | LSX | 4 hr |
| Jun 14, 12:31 PM CDT | Severe Thunderstorm Warning | LSX | 29 min |
| Jun 14, 12:40 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 14, 12:51 PM CDT | Severe Thunderstorm Warning | LSX | 39 min |
| Jun 14, 1:04 PM CDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 14, 3:09 PM CDT | Special Weather Statement | LSX | 66 min |
| Jun 14, 6:11 PM CDT | Mesoscale Discussion | SPC | 64 min |
| Jun 16, 4:36 PM CDT | Severe Thunderstorm Warning | LSX | 22 min |
| Jun 17, 9:50 PM CDT | Mesoscale Discussion | SPC | 55 min |
| Jun 17, 10:53 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 18, 12:34 AM CDT | Special Weather Statement | LSX | 56 min |
| Jun 29, 1:45 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 29, 3:22 PM CDT | Severe Thunderstorm Warning | LSX | 40 min |
| Jul 10, 4:04 AM CDT | Heat Advisory | LSX | 4 days |
| Jul 15, 2:30 PM CDT | Excessive Heat Watch | LSX | 3 days |
| Jul 16, 2:06 PM CDT | Mesoscale Discussion | SPC | 54 min |
| Jul 17, 3:00 PM CDT | Excessive Heat Warning | LSX | 6 days |
| Jul 22, 11:48 PM CDT | Mesoscale Discussion | SPC | 87 min |
| Jul 23, 12:38 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 23, 1:46 AM CDT | Severe Thunderstorm Warning | LSX | 44 min |
| Jul 23, 2:17 AM CDT | Severe Thunderstorm Warning | LSX | 43 min |
| Jul 23, 2:48 AM CDT | Severe Thunderstorm Warning | LSX | 42 min |
| Jul 23, 3:12 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 25, 3:42 AM CDT | Heat Advisory | LSX | 40 hr |
| Jul 27, 1:19 AM CDT | Severe Thunderstorm Warning | LSX | 41 min |
| Aug 16, 2:35 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 16, 4:28 PM CDT | Special Weather Statement | LSX | 47 min |
| Aug 21, 3:29 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Aug 29, 4:15 AM CDT | Dense Fog Advisory | LSX | 6 hr |
| Sep 4, 4:00 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Sep 4, 6:05 PM CDT | Mesoscale Discussion | SPC | 115 min |
| Sep 4, 6:25 PM CDT | Severe Thunderstorm Warning | LSX | 50 min |
| Sep 4, 7:08 PM CDT | Severe Thunderstorm Warning | LSX | 52 min |
| Sep 14, 3:19 AM CDT | Dense Fog Advisory | LSX | 6 hr |
| Sep 18, 11:19 PM CDT | Dense Fog Advisory | LSX | 11 hr |
| Oct 8, 5:23 AM CDT | Dense Fog Advisory | LSX | 4 hr |
| Oct 9, 5:22 AM CDT | Dense Fog Advisory | LSX | 6 hr |
| Oct 9, 7:58 PM CDT | Severe Thunderstorm Warning | LSX | 47 min |
| Oct 14, 9:04 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Oct 27, 3:34 AM CDT | Freeze Watch | LSX | 12 hr |
| Oct 27, 3:09 PM CDT | Freeze Warning | LSX | 42 hr |
| Nov 5, 12:35 PM CST | Tornado Watch | SPC | 6 hr |
| Nov 5, 1:59 PM CST | Severe Thunderstorm Warning | LSX | 46 min |
| Nov 5, 2:51 PM CST | Mesoscale Discussion | SPC | 114 min |
| Nov 17, 3:35 PM CST | Wind Advisory | LSX | 26 hr |
| Dec 11, 3:04 AM CST | Red Flag Warning | LSX | 15 hr |
| Dec 29, 3:39 AM CST | Winter Weather Advisory | LSX | 23 hr |
| Dec 29, 3:10 PM CST | Wind Chill Advisory | LSX | 4 days |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20162018
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.