Alert archive / Mississippi / Simpson County
Weather alerts in Simpson County, Mississippi, 2021
152 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Simpson County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 152
- Warnings
- 46
- Watches
- 17
- Advisories
- 32
- Busiest month
- March23 alerts
- Busiest day
- May 4, 202111 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
4 of 6 tornado warnings covering Simpson County in 2021 had a tornado report inside them; 2 of 5 tornado reports fell inside a warning, on average 10 minutes after it went out.
Simpson County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 6 | 4 | 33% | 5 | 40% | 10 min |
| Severe thunderstorm warnings | 18 | 11 | 39% | 4 | 50% | 30 min |
| Flash flood warnings | 6 | 5 | 17% | 5 | 80% | 127 min |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Jackson, MS: tornado warnings | 62 | 22 | 65% | 76 | 61% | 21 min |
| NWS Jackson, MS: severe thunderstorm warnings | 296 | 169 | 43% | 530 | 86% | 28 min |
| NWS Jackson, MS: flash flood warnings | 110 | 66 | 40% | 199 | 83% | 83 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 |
|---|---|---|---|
| Dec 31, 9:31 PM CST | Mesoscale Discussion | SPC | 119 min |
| Jan 1, 1:04 AM CST | Mesoscale Discussion | SPC | 116 min |
| Jan 10, 3:52 AM CST | Winter Weather Advisory | JAN | 32 hr |
| Jan 13, 6:15 AM CST | Winter Weather Advisory | JAN | 6 hr |
| Jan 15, 4:01 AM CST | Wind Advisory | JAN | 14 hr |
| Jan 25, 10:59 PM CST | Severe Thunderstorm Warning | JAN | 20 min |
| Feb 10, 2:09 PM CST | Dense Fog Advisory | JAN | 16 hr |
| Feb 12, 4:09 PM CST | Winter Storm Watch | JAN | 23 hr |
| Feb 13, 3:13 PM CST | Winter Storm Warning | JAN | 48 hr |
| Feb 14, 9:09 PM CST | Hard Freeze Warning | JAN | 63 hr |
| Feb 14, 9:41 PM CST | Wind Chill Advisory | JAN | 35 hr |
| Feb 15, 3:09 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Feb 15, 9:28 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Feb 16, 2:50 PM CST | Winter Storm Warning | JAN | 39 hr |
| Feb 16, 2:50 PM CST | Winter Weather Advisory | JAN | 39 hr |
| Feb 17, 10:53 AM CST | Mesoscale Discussion | SPC | 6 hr |
| Feb 18, 6:25 AM CST | Winter Weather Advisory | JAN | 14 hr |
| Mar 16, 11:49 AM CDT | Flash Flood Watch | JAN | 7 hr |
| Mar 16, 7:01 PM CDT | Tornado Warning | JAN | 31 min |
| Mar 16, 7:32 PM CDT | Severe Thunderstorm Warning | JAN | 58 min |
| Mar 16, 8:29 PM CDT | Special Weather Statement | JAN | 46 min |
| Mar 17, 10:56 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Mar 17, 11:36 AM CDT | Tornado Watch | SPC | 7 hr |
| Mar 17, 1:19 PM CDT | Mesoscale Discussion | SPC | 86 min |
| Mar 17, 2:56 PM CDT | Mesoscale Discussion | SPC | 94 min |
| Mar 17, 6:12 PM CDT | Severe Thunderstorm Warning | JAN | 48 min |
| Mar 22, 2:25 PM CDT | Wind Advisory | JAN | 23 hr |
| Mar 24, 12:10 PM CDT | Wind Advisory | JAN | 26 hr |
| Mar 24, 9:25 PM CDT | Mesoscale Discussion | SPC | 65 min |
| Mar 25, 3:07 AM CDT | Special Weather Statement | JAN | 38 min |
| Mar 25, 11:26 AM CDT | Tornado Watch | SPC | 9 hr |
| Mar 25, 1:03 PM CDT | Tornado Warning | JAN | 57 min |
| Mar 25, 1:24 PM CDT | Flash Flood Warning | JAN | 94 min |
| Mar 25, 3:40 PM CDT | Severe Thunderstorm Warning | JAN | 65 min |
| Mar 30, 5:46 PM CDT | Mesoscale Discussion | SPC | 119 min |
| Mar 30, 7:30 PM CDT | Special Weather Statement | JAN | 45 min |
| Mar 30, 7:47 PM CDT | Severe Thunderstorm Warning | JAN | 33 min |
| Mar 31, 11:11 AM CDT | Special Weather Statement | JAN | 64 min |
| Mar 31, 11:19 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Mar 31, 11:29 AM CDT | Severe Thunderstorm Warning | JAN | 61 min |
| Apr 1, 10:41 AM CDT | Freeze Watch | JAN | 17 hr |
| Apr 2, 9:51 AM CDT | Freeze Warning | JAN | 22 hr |
| Apr 6, 5:15 AM CDT | Dense Fog Advisory | JAN | 4 hr |
| Apr 7, 5:12 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 7, 8:52 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 8, 6:11 AM CDT | Dense Fog Advisory | JAN | 3 hr |
| Apr 9, 3:42 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Apr 9, 10:25 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Apr 9, 11:00 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 10, 12:53 AM CDT | Flash Flood Warning | JAN | 3 hr |
| Apr 10, 9:40 AM CDT | River Flood Warning | JAN | 21 days |
| Apr 10, 9:40 AM CDT | River Flood Warning | JAN | 35 hr |
| Apr 11, 8:25 PM CDT | River Flood Advisory | JAN | 7 min |
| Apr 17, 10:00 AM CDT | River Flood Warning | JAN | 48 hr |
| Apr 23, 3:22 PM CDT | Flash Flood Watch | JAN | 14 hr |
| Apr 23, 8:30 PM CDT | Tornado Watch | SPC | 8 hr |
| Apr 24, 9:00 AM CDT | River Flood Warning | JAN | 3 days |
| Apr 24, 12:29 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 27, 2:47 AM CDT | Dense Fog Advisory | JAN | 6 hr |
| May 2, 3:33 PM CDT | Mesoscale Discussion | SPC | 117 min |
| May 4, 3:50 AM CDT | Flash Flood Watch | JAN | 18 hr |
| May 4, 7:58 AM CDT | Severe Thunderstorm Warning | JAN | 62 min |
| May 4, 8:19 AM CDT | Tornado Warning | JAN | 56 min |
| May 4, 8:33 AM CDT | Mesoscale Discussion | SPC | 117 min |
| May 4, 9:06 AM CDT | Tornado Warning | JAN | 54 min |
| May 4, 9:18 AM CDT | Tornado Watch | SPC | 7 hr |
| May 4, 1:31 PM CDT | Severe Thunderstorm Warning | JAN | 44 min |
| May 4, 2:12 PM CDT | Severe Thunderstorm Warning | JAN | 93 min |
| May 4, 2:17 PM CDT | Mesoscale Discussion | SPC | 88 min |
| May 4, 2:40 PM CDT | Severe Thunderstorm Warning | JAN | 80 min |
| May 4, 3:09 PM CDT | Severe Thunderstorm Warning | JAN | 81 min |
| May 9, 3:53 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| May 18, 3:10 PM CDT | Tornado Warning | JAN | 38 min |
| May 18, 3:57 PM CDT | Tornado Warning | JAN | 36 min |
| May 18, 4:17 PM CDT | Mesoscale Discussion | SPC | 118 min |
| May 18, 7:39 PM CDT | Flash Flood Warning | JAN | 93 min |
| Jun 2, 2:34 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Jun 2, 5:59 PM CDT | Special Weather Statement | JAN | 46 min |
| Jun 2, 6:53 PM CDT | Special Weather Statement | JAN | 52 min |
| Jun 6, 3:01 AM CDT | Flash Flood Watch | JAN | 15 hr |
| Jun 6, 9:28 AM CDT | Flash Flood Warning | JAN | 3 hr |
| Jun 9, 8:00 PM CDT | Special Weather Statement | JAN | 45 min |
| Jun 9, 8:31 PM CDT | Special Weather Statement | JAN | 29 min |
| Jun 9, 8:42 PM CDT | Severe Thunderstorm Warning | JAN | 63 min |
| Jun 11, 11:19 AM CDT | River Flood Warning | JAN | 21 days |
| Jun 13, 10:45 AM CDT | Mesoscale Discussion | SPC | 60 min |
| Jun 13, 12:22 PM CDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 13, 4:19 PM CDT | Severe Thunderstorm Warning | JAN | 56 min |
| Jun 13, 5:00 PM CDT | Special Weather Statement | JAN | 60 min |
| Jun 14, 3:04 AM CDT | Heat Advisory | JAN | 12 hr |
| Jun 14, 5:04 PM CDT | Severe Thunderstorm Warning | JAN | 41 min |
| Jun 14, 5:41 PM CDT | Special Weather Statement | JAN | 64 min |
| Jun 14, 6:09 PM CDT | Severe Thunderstorm Warning | JAN | 51 min |
| Jun 18, 8:55 AM CDT | River Flood Warning | JAN | 23 hr |
| Jun 18, 2:53 PM CDT | Wind Advisory | JAN | 18 hr |
| Jun 21, 4:38 PM CDT | Special Weather Statement | JAN | 52 min |
| Jun 21, 6:35 PM CDT | Special Weather Statement | JAN | 55 min |
| Jun 21, 7:17 PM CDT | Mesoscale Discussion | SPC | 118 min |
| Jul 7, 1:13 PM CDT | Special Weather Statement | JAN | 32 min |
| Jul 11, 10:32 AM CDT | Special Weather Statement | JAN | 43 min |
| Jul 12, 9:37 AM CDT | Special Weather Statement | JAN | 53 min |
| Jul 16, 11:19 AM CDT | Severe Thunderstorm Warning | JAN | 32 min |
| Jul 17, 4:31 PM CDT | Special Weather Statement | JAN | 14 min |
| Jul 18, 2:14 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 18, 7:56 PM CDT | Special Weather Statement | JAN | 49 min |
| Jul 23, 2:40 PM CDT | Heat Advisory | JAN | 28 hr |
| Jul 24, 2:55 PM CDT | Heat Advisory | JAN | 28 hr |
| Jul 25, 2:32 PM CDT | Heat Advisory | JAN | 28 hr |
| Jul 26, 2:54 PM CDT | Heat Advisory | JAN | 28 hr |
| Jul 27, 2:54 PM CDT | Excessive Heat Warning | JAN | 4 days |
| Jul 27, 2:54 PM CDT | Heat Advisory | JAN | 5 days |
| Jul 28, 6:17 PM CDT | Special Weather Statement | JAN | 28 min |
| Aug 1, 12:09 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 11, 4:36 PM CDT | Special Weather Statement | JAN | 24 min |
| Aug 11, 4:46 PM CDT | Special Weather Statement | JAN | 29 min |
| Aug 18, 7:25 PM CDT | Special Weather Statement | JAN | 50 min |
| Aug 20, 3:05 PM CDT | Heat Advisory | JAN | 3 days |
| Aug 23, 3:27 PM CDT | Heat Advisory | JAN | 28 hr |
| Aug 24, 3:01 PM CDT | Heat Advisory | JAN | 28 hr |
| Aug 27, 4:10 PM CDT | Tropical Storm Watch | JAN | 24 hr |
| Aug 28, 3:36 AM CDT | Flash Flood Watch | JAN | 66 hr |
| Aug 28, 10:00 AM CDT | Tropical Storm Warning | JAN | 54 hr |
| Aug 28, 3:41 PM CDT | Special Weather Statement | JAN | 34 min |
| Aug 29, 10:37 AM CDT | River Flood Warning | JAN | 58 hr |
| Aug 29, 10:37 AM CDT | River Flood Warning | JAN | 4 days |
| Aug 29, 11:49 AM CDT | Special Weather Statement | JAN | 41 min |
| Aug 30, 6:41 AM CDT | Flash Flood Warning | JAN | 4 hr |
| Aug 30, 8:33 AM CDT | Flash Flood Warning | JAN | 4 hr |
| Aug 30, 9:24 PM CDT | River Flood Warning | JAN | 40 hr |
| Sep 1, 4:08 AM CDT | Heat Advisory | JAN | 15 hr |
| Sep 1, 6:05 PM CDT | Special Weather Statement | JAN | 55 min |
| Sep 1, 6:14 PM CDT | Severe Thunderstorm Warning | JAN | 76 min |
| Sep 1, 6:37 PM CDT | Severe Thunderstorm Warning | JAN | 53 min |
| Sep 1, 7:18 PM CDT | Special Weather Statement | JAN | 27 min |
| Sep 1, 7:21 PM CDT | Mesoscale Discussion | SPC | 84 min |
| Sep 21, 6:10 PM CDT | Special Weather Statement | JAN | 50 min |
| Sep 28, 6:34 AM CDT | Dense Fog Advisory | JAN | 3 hr |
| Oct 4, 2:54 AM CDT | Dense Fog Advisory | JAN | 6 hr |
| Oct 27, 5:16 PM CDT | Special Weather Statement | JAN | 74 min |
| Nov 6, 2:29 AM CDT | Dense Fog Advisory | JAN | 8 hr |
| Nov 6, 10:16 PM CDT | Dense Fog Advisory | JAN | 13 hr |
| Nov 11, 9:29 PM CST | Dense Fog Advisory | JAN | 12 hr |
| Nov 12, 2:59 PM CST | Freeze Watch | JAN | 12 hr |
| Nov 13, 3:17 AM CST | Freeze Warning | JAN | 29 hr |
| Dec 2, 8:58 PM CST | Dense Fog Advisory | JAN | 13 hr |
| Dec 4, 3:02 PM CST | Dense Fog Advisory | JAN | 18 hr |
| Dec 6, 10:06 AM CST | Mesoscale Discussion | SPC | 114 min |
| Dec 6, 11:05 AM CST | Special Weather Statement | JAN | 40 min |
| Dec 16, 3:20 PM CST | Dense Fog Advisory | JAN | 16 hr |
| Dec 28, 1:18 PM CST | Mesoscale Discussion | SPC | 2 hr |
| Dec 29, 2:03 PM CST | Mesoscale Discussion | SPC | 87 min |
| Dec 30, 4:02 AM CST | Mesoscale Discussion | SPC | 2 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 | 18 |
| Tornado Warning | 6 |
| Severe Thunderstorm Watch | 4 |
| Tornado Watch | 4 |
| Mesoscale Discussion | 29 |
| Special Weather Statement | 28 |
| Flooding | |
| Flash Flood Warning | 6 |
| River Flood Warning | 9 |
| Flash Flood Watch | 5 |
| River Flood Advisory | 1 |
| Winter | |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 4 |
| Heat | |
| Excessive Heat Warning | 1 |
| Heat Advisory | 10 |
| Cold | |
| Freeze Warning | 2 |
| Hard Freeze Warning | 1 |
| Freeze Watch | 2 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| Wind Advisory | 4 |
| Fog and smoke | |
| Dense Fog Advisory | 12 |
| Tropical | |
| Tropical Storm Warning | 1 |
| Tropical Storm Watch | 1 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20202022
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.