Alert archive / Missouri / Saint Louis County
Weather alerts in Saint Louis County, Missouri, 2018
135 weather alerts in 2018, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Saint Louis County and its neighbors
Each county as a circle sized by its count in 2018. Tap one for its archive.
- Alerts
- 135
- Warnings
- 43
- Watches
- 12
- Advisories
- 35
- Busiest month
- June34 alerts
- Busiest day
- June 28, 20188 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 Saint Louis County in 2018 had a tornado report inside them.
Saint Louis County, 2018
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 2 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 22 | 14 | 36% | 26 | 85% | 24 min |
| Flash flood warnings | 1 | 0 | 100% | 1 | 0% |
Each office's whole area, 2018
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS St. Louis, MO: tornado warnings | 20 | 3 | 85% | 19 | 42% | 14 min |
| NWS St. Louis, MO: severe thunderstorm warnings | 218 | 101 | 54% | 375 | 80% | 23 min |
| NWS St. Louis, MO: flash flood warnings | 45 | 19 | 58% | 48 | 85% | 90 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, 3:57 PM CST | Wind Chill Advisory | LSX | 43 hr |
| Jan 6, 3:35 AM CST | Winter Weather Advisory | LSX | 44 hr |
| Jan 8, 3:36 PM CST | Dense Fog Advisory | LSX | 20 hr |
| Jan 9, 3:28 PM CST | Dense Fog Advisory | LSX | 18 hr |
| Jan 11, 3:14 AM CST | Winter Weather Advisory | LSX | 27 hr |
| Jan 14, 3:22 PM CST | Wind Chill Advisory | LSX | 45 hr |
| Jan 14, 3:22 PM CST | Winter Weather Advisory | LSX | 21 hr |
| Feb 5, 11:15 AM CST | Winter Weather Advisory | LSX | 13 hr |
| Feb 6, 3:34 AM CST | Winter Weather Advisory | LSX | 25 hr |
| Feb 10, 4:20 AM CST | Winter Weather Advisory | LSX | 29 hr |
| Feb 17, 9:16 AM CST | Winter Weather Advisory | LSX | 4 hr |
| Feb 20, 2:50 PM CST | Winter Weather Advisory | LSX | 44 hr |
| Feb 20, 2:59 PM CST | Flood Watch | LSX | 15 hr |
| Feb 20, 9:18 PM CST | Mesoscale Discussion | SPC | 6 hr |
| Feb 21, 3:33 AM CST | Winter Weather Advisory | LSX | 31 hr |
| Feb 22, 3:24 PM CST | Flood Watch | LSX | 52 hr |
| Feb 24, 4:56 AM CST | Areal Flood Advisory | LSX | 4 hr |
| Feb 25, 8:09 AM CST | River Flood Warning | LSX | 4 days |
| Feb 25, 8:09 AM CST | River Flood Warning | LSX | 4 days |
| Feb 25, 8:21 PM CST | River Flood Warning | LSX | 5 days |
| Mar 25, 3:16 PM CDT | Flood Watch | LSX | 54 hr |
| Mar 29, 4:18 PM CDT | River Flood Warning | LSX | 64 hr |
| Mar 29, 4:18 PM CDT | River Flood Warning | LSX | 4 days |
| Mar 31, 3:36 PM CDT | Winter Weather Advisory | LSX | 30 hr |
| Apr 2, 10:46 PM CDT | Mesoscale Discussion | SPC | 119 min |
| Apr 2, 11:13 PM CDT | Severe Thunderstorm Warning | LSX | 32 min |
| Apr 3, 12:02 AM CDT | Special Weather Statement | LSX | 43 min |
| Apr 13, 5:27 PM CDT | Tornado Watch | SPC | 8 hr |
| Apr 13, 8:42 PM CDT | Mesoscale Discussion | SPC | 63 min |
| Apr 13, 9:53 PM CDT | Severe Thunderstorm Warning | LSX | 67 min |
| Apr 15, 3:52 AM CDT | Freeze Warning | LSX | 29 hr |
| Apr 16, 3:25 AM CDT | Freeze Warning | LSX | 30 hr |
| Apr 18, 10:24 AM CDT | Wind Advisory | LSX | 9 hr |
| Apr 19, 2:46 AM CDT | Frost Advisory | LSX | 30 hr |
| May 2, 10:20 PM CDT | Mesoscale Discussion | SPC | 115 min |
| May 2, 11:09 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 3, 2:32 AM CDT | Mesoscale Discussion | SPC | 88 min |
| May 3, 3:43 AM CDT | Severe Thunderstorm Warning | LSX | 47 min |
| May 6, 7:10 PM CDT | Special Weather Statement | LSX | 50 min |
| May 14, 1:20 PM CDT | Severe Thunderstorm Watch | SPC | 11 hr |
| May 14, 5:19 PM CDT | Severe Thunderstorm Warning | LSX | 56 min |
| May 14, 5:52 PM CDT | Special Weather Statement | LSX | 38 min |
| May 14, 6:14 PM CDT | Special Weather Statement | LSX | 46 min |
| May 14, 6:29 PM CDT | Severe Thunderstorm Warning | LSX | 61 min |
| May 14, 6:36 PM CDT | Mesoscale Discussion | SPC | 84 min |
| May 19, 2:38 PM CDT | Severe Thunderstorm Warning | LSX | 18 min |
| May 27, 1:23 AM CDT | Areal Flood Advisory | LSX | 94 min |
| May 27, 1:58 AM CDT | Severe Thunderstorm Warning | LSX | 34 min |
| May 27, 3:28 PM CDT | Severe Thunderstorm Warning | LSX | 32 min |
| May 27, 3:47 PM CDT | Mesoscale Discussion | SPC | 118 min |
| May 27, 3:54 PM CDT | Areal Flood Advisory | LSX | 3 hr |
| May 27, 6:11 PM CDT | Severe Thunderstorm Warning | LSX | 40 min |
| Jun 2, 9:12 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 2, 10:02 AM CDT | Special Weather Statement | LSX | 43 min |
| Jun 9, 10:51 AM CDT | Severe Thunderstorm Warning | LSX | 39 min |
| Jun 9, 11:09 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 9, 11:25 AM CDT | Severe Thunderstorm Warning | LSX | 42 min |
| Jun 9, 12:30 PM CDT | Special Weather Statement | LSX | 45 min |
| Jun 10, 7:01 PM CDT | Mesoscale Discussion | SPC | 59 min |
| Jun 11, 4:53 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 14, 3:50 AM CDT | Heat Advisory | LSX | 24 hr |
| Jun 14, 5:18 PM CDT | Mesoscale Discussion | SPC | 57 min |
| Jun 14, 5:37 PM CDT | Severe Thunderstorm Warning | LSX | 38 min |
| Jun 14, 6:08 PM CDT | Severe Thunderstorm Warning | LSX | 52 min |
| Jun 15, 3:53 AM CDT | Excessive Heat Warning | LSX | 5 days |
| Jun 19, 6:46 PM CDT | Special Weather Statement | LSX | 44 min |
| Jun 19, 7:12 PM CDT | Severe Thunderstorm Warning | LSX | 48 min |
| Jun 25, 3:23 PM CDT | Mesoscale Discussion | SPC | 97 min |
| Jun 25, 3:32 PM CDT | Excessive Heat Watch | LSX | 36 hr |
| Jun 25, 6:53 PM CDT | Special Weather Statement | LSX | 52 min |
| Jun 25, 7:04 PM CDT | Severe Thunderstorm Warning | LSX | 41 min |
| Jun 25, 7:12 PM CDT | Severe Thunderstorm Warning | LSX | 48 min |
| Jun 25, 7:48 PM CDT | Severe Thunderstorm Warning | LSX | 42 min |
| Jun 25, 8:08 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 26, 2:19 AM CDT | Mesoscale Discussion | SPC | 116 min |
| Jun 26, 7:39 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 26, 2:22 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 27, 3:46 AM CDT | Heat Advisory | LSX | 5 days |
| Jun 28, 2:00 AM CDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 28, 8:43 AM CDT | Mesoscale Discussion | SPC | 62 min |
| Jun 28, 1:04 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 28, 3:34 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jun 28, 3:52 PM CDT | Excessive Heat Warning | LSX | 3 days |
| Jun 28, 5:02 PM CDT | Severe Thunderstorm Warning | LSX | 73 min |
| Jun 28, 5:22 PM CDT | Severe Thunderstorm Warning | LSX | 83 min |
| Jun 28, 5:29 PM CDT | Tornado Warning | LSX | 16 min |
| Jul 1, 4:59 PM CDT | Special Weather Statement | LSX | 46 min |
| Jul 1, 6:38 PM CDT | Special Weather Statement | LSX | 52 min |
| Jul 1, 6:51 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Jul 3, 3:31 AM CDT | Heat Advisory | LSX | 64 hr |
| Jul 12, 3:35 AM CDT | Heat Advisory | LSX | 64 hr |
| Jul 14, 3:49 PM CDT | Severe Thunderstorm Warning | LSX | 41 min |
| Jul 14, 5:24 PM CDT | Special Weather Statement | LSX | 51 min |
| Jul 14, 5:44 PM CDT | Severe Thunderstorm Warning | LSX | 46 min |
| Jul 19, 6:49 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 2, 4:21 PM CDT | Special Weather Statement | LSX | 39 min |
| Aug 10, 3:48 PM CDT | Special Weather Statement | LSX | 42 min |
| Aug 10, 4:02 PM CDT | Severe Thunderstorm Warning | LSX | 43 min |
| Aug 10, 4:40 PM CDT | Areal Flood Advisory | LSX | 2 hr |
| Aug 10, 4:48 PM CDT | Flash Flood Warning | LSX | 2 hr |
| Aug 10, 4:56 PM CDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 10, 5:12 PM CDT | Special Weather Statement | LSX | 48 min |
| Aug 16, 10:40 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 20, 11:46 AM CDT | Mesoscale Discussion | SPC | 119 min |
| Aug 20, 12:46 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 20, 4:23 PM CDT | Special Weather Statement | LSX | 52 min |
| Aug 24, 3:33 PM CDT | Heat Advisory | LSX | 4 days |
| Aug 26, 3:43 AM CDT | Excessive Heat Warning | LSX | 63 hr |
| Aug 29, 4:23 AM CDT | Special Weather Statement | LSX | 52 min |
| Sep 6, 3:21 AM CDT | Flash Flood Watch | LSX | 60 hr |
| Sep 6, 11:27 AM CDT | River Flood Warning | LSX | 6 days |
| Sep 6, 11:52 AM CDT | River Flood Warning | LSX | 48 hr |
| Sep 7, 9:27 PM CDT | Areal Flood Advisory | LSX | 4 hr |
| Sep 8, 8:44 AM CDT | Areal Flood Warning | LSX | 6 hr |
| Oct 6, 12:39 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 7, 5:33 AM CDT | Dense Fog Advisory | LSX | 3 hr |
| Oct 7, 1:33 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 7, 3:53 PM CDT | Special Weather Statement | LSX | 52 min |
| Oct 8, 11:36 AM CDT | River Flood Warning | LSX | 17 days |
| Oct 8, 12:20 PM CDT | River Flood Warning | LSX | 13 days |
| Oct 8, 9:50 PM CDT | River Flood Warning | LSX | 10 days |
| Oct 15, 4:02 AM CDT | Frost Advisory | LSX | 29 hr |
| Oct 20, 3:18 AM CDT | Freeze Warning | LSX | 29 hr |
| Oct 27, 3:25 PM CDT | Wind Advisory | LSX | 27 hr |
| Nov 2, 7:04 AM CDT | Dense Fog Advisory | LSX | 3 hr |
| Nov 3, 3:03 AM CDT | Dense Fog Advisory | LSX | 6 hr |
| Nov 9, 10:52 AM CST | Winter Weather Advisory | LSX | 10 hr |
| Nov 11, 2:00 PM CST | Winter Weather Advisory | LSX | 36 hr |
| Nov 14, 2:32 AM CST | Winter Storm Warning | LSX | 36 hr |
| Nov 14, 2:32 AM CST | Winter Weather Advisory | LSX | 36 hr |
| Nov 25, 11:22 AM CST | Wind Advisory | LSX | 19 hr |
| Nov 25, 4:30 PM CST | Special Weather Statement | LSX | 30 min |
| Nov 25, 4:36 PM CST | Mesoscale Discussion | SPC | 84 min |
| Nov 25, 4:46 PM CST | Tornado Warning | LSX | 29 min |
| Dec 1, 1:48 PM CST | Mesoscale Discussion | SPC | 117 min |
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 archive20172019
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.