Alert archive / Tennessee / Johnson County
Weather alerts in Johnson County, Tennessee, 2024
103 weather alerts in 2024, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Johnson County and its neighbors
Each county as a circle sized by its count in 2024. Tap one for its archive.
- Alerts
- 103
- Warnings
- 25
- Watches
- 13
- Advisories
- 42
- Busiest month
- September21 alerts
- Busiest day
- May 26, 20246 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Johnson County, 2024
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 5 | 2 | 60% | 0 | ||
| Flash flood warnings | 7 | 3 | 57% | 4 | 100% | 80 min |
Each office's whole area, 2024
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Morristown, TN: tornado warnings | 18 | 3 | 83% | 4 | 100% | 11 min |
| NWS Morristown, TN: severe thunderstorm warnings | 189 | 140 | 26% | 229 | 86% | 22 min |
| NWS Morristown, TN: flash flood warnings | 61 | 35 | 43% | 92 | 76% | 75 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, Eastern Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 5, 3:47 AM EST | Wind Advisory | MRX | 11 hr |
| Jan 5, 3:11 PM EST | High Wind Warning | MRX | 19 hr |
| Jan 7, 3:21 AM EST | High Wind Watch | MRX | 24 hr |
| Jan 8, 3:45 AM EST | High Wind Warning | MRX | 39 hr |
| Jan 8, 3:45 AM EST | Wind Advisory | MRX | 57 hr |
| Jan 9, 8:59 PM EST | Winter Weather Advisory | MRX | 12 hr |
| Jan 10, 3:04 PM EST | High Wind Watch | MRX | 12 hr |
| Jan 11, 3:21 AM EST | High Wind Warning | MRX | 39 hr |
| Jan 11, 3:21 AM EST | Wind Advisory | MRX | 60 hr |
| Jan 13, 3:39 AM EST | Winter Storm Watch | MRX | 24 hr |
| Jan 14, 3:43 AM EST | Winter Storm Warning | MRX | 51 hr |
| Jan 16, 3:22 AM EST | Wind Chill Advisory | MRX | 33 hr |
| Jan 17, 3:18 PM EST | Winter Weather Advisory | MRX | 64 hr |
| Jan 18, 3:04 PM EST | Wind Chill Watch | MRX | 13 hr |
| Jan 19, 3:39 AM EST | Wind Chill Warning | MRX | 54 hr |
| Jan 26, 3:16 PM EST | Flood Watch | MRX | 23 hr |
| Jan 27, 2:55 PM EST | Winter Storm Warning | MRX | 43 hr |
| Feb 12, 3:23 AM EST | Wind Advisory | MRX | 28 hr |
| Feb 12, 4:55 PM EST | Winter Weather Advisory | MRX | 14 hr |
| Feb 12, 9:52 PM EST | Special Weather Statement | MRX | 53 min |
| Feb 23, 3:55 PM EST | Winter Weather Advisory | MRX | 28 hr |
| Feb 26, 3:00 PM EST | Wind Advisory | MRX | 52 hr |
| Feb 29, 2:54 PM EST | Wind Advisory | MRX | 33 hr |
| Mar 7, 2:36 PM EST | Wind Advisory | MRX | 43 hr |
| Mar 9, 3:27 AM EST | Wind Advisory | MRX | 41 hr |
| Mar 21, 1:37 PM EDT | Wind Advisory | MRX | 34 hr |
| Mar 24, 2:51 PM EDT | High Wind Watch | MRX | 12 hr |
| Mar 24, 2:51 PM EDT | Wind Advisory | MRX | 44 hr |
| Mar 25, 2:36 AM EDT | High Wind Warning | MRX | 37 hr |
| Apr 3, 3:28 PM EDT | Winter Weather Advisory | MRX | 36 hr |
| Apr 12, 3:41 AM EDT | Wind Advisory | MRX | 17 hr |
| Apr 16, 2:15 PM EDT | Special Weather Statement | MRX | 45 min |
| Apr 16, 2:27 PM EDT | Severe Thunderstorm Warning | MRX | 29 min |
| Apr 16, 2:53 PM EDT | Areal Flood Advisory | MRX | 112 min |
| Apr 19, 2:33 PM EDT | Mesoscale Discussion | SPC | 117 min |
| Apr 21, 3:25 AM EDT | Frost Advisory | MRX | 30 hr |
| Apr 22, 2:43 PM EDT | Frost Advisory | MRX | 18 hr |
| May 1, 3:16 AM EDT | Dense Fog Advisory | MRX | 7 hr |
| May 7, 5:05 PM EDT | Mesoscale Discussion | SPC | 85 min |
| May 8, 2:28 AM EDT | Flood Watch | MRX | 30 hr |
| May 8, 10:04 AM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 11, 5:58 AM EDT | Dense Fog Advisory | MRX | 3 hr |
| May 15, 4:53 PM EDT | Special Weather Statement | MRX | 52 min |
| May 26, 1:13 PM EDT | Mesoscale Discussion | SPC | 92 min |
| May 26, 1:46 PM EDT | Severe Thunderstorm Watch | SPC | 9 hr |
| May 26, 3:25 PM EDT | Mesoscale Discussion | SPC | 95 min |
| May 26, 5:00 PM EDT | Mesoscale Discussion | SPC | 90 min |
| May 26, 5:59 PM EDT | Special Weather Statement | MRX | 46 min |
| May 26, 6:06 PM EDT | Areal Flood Advisory | MRX | 3 hr |
| Jun 10, 4:45 AM EDT | Dense Fog Advisory | MRX | 4 hr |
| Jun 17, 3:17 PM EDT | Special Weather Statement | MRX | 43 min |
| Jun 30, 12:42 PM EDT | Special Weather Statement | MRX | 48 min |
| Jun 30, 2:16 PM EDT | Mesoscale Discussion | SPC | 119 min |
| Jun 30, 4:38 PM EDT | Areal Flood Advisory | MRX | 3 hr |
| Jul 5, 3:28 PM EDT | Special Weather Statement | MRX | 47 min |
| Jul 30, 3:36 AM EDT | Flood Watch | MRX | 4 days |
| Jul 30, 8:10 AM EDT | Special Weather Statement | MRX | 50 min |
| Aug 2, 1:37 PM EDT | Areal Flood Advisory | MRX | 113 min |
| Aug 2, 1:43 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 16, 5:58 PM EDT | Severe Thunderstorm Warning | MRX | 62 min |
| Aug 16, 6:34 PM EDT | Severe Thunderstorm Warning | MRX | 56 min |
| Aug 18, 4:37 PM EDT | Special Weather Statement | MRX | 53 min |
| Aug 29, 5:42 PM EDT | Severe Thunderstorm Warning | MRX | 33 min |
| Aug 30, 6:15 PM EDT | Special Weather Statement | MRX | 45 min |
| Aug 30, 8:09 PM EDT | Special Weather Statement | MRX | 36 min |
| Aug 30, 8:50 PM EDT | Special Weather Statement | MRX | 40 min |
| Sep 13, 3:13 PM EDT | Wind Advisory | MRX | 17 hr |
| Sep 23, 2:13 PM EDT | Mesoscale Discussion | SPC | 92 min |
| Sep 24, 1:55 PM EDT | Mesoscale Discussion | SPC | 65 min |
| Sep 24, 2:55 PM EDT | Flood Watch | MRX | 71 hr |
| Sep 24, 7:42 PM EDT | Severe Thunderstorm Warning | MRX | 63 min |
| Sep 24, 8:37 PM EDT | Special Weather Statement | MRX | 53 min |
| Sep 25, 1:15 AM EDT | Areal Flood Advisory | MRX | 3 hr |
| Sep 25, 1:38 PM EDT | High Wind Watch | MRX | 23 hr |
| Sep 25, 8:10 PM EDT | Flash Flood Warning | MRX | 3 hr |
| Sep 25, 9:40 PM EDT | High Wind Warning | MRX | 55 hr |
| Sep 25, 11:13 PM EDT | Flash Flood Warning | MRX | 13 hr |
| Sep 26, 12:07 PM EDT | Areal Flood Warning | MRX | 5 hr |
| Sep 26, 4:59 PM EDT | Areal Flood Warning | MRX | 12 hr |
| Sep 27, 8:50 AM EDT | Areal Flood Warning | MRX | 3 hr |
| Sep 27, 9:35 AM EDT | Flash Flood Warning | MRX | 10 hr |
| Sep 27, 2:29 PM EDT | Wind Advisory | MRX | 24 hr |
| Sep 27, 4:54 PM EDT | Flash Flood Warning | MRX | 3 hr |
| Sep 27, 7:29 PM EDT | Flash Flood Warning | MRX | 6 hr |
| Sep 27, 7:38 PM EDT | Flash Flood Warning | MRX | 6 hr |
| Sep 28, 1:08 AM EDT | Flash Flood Warning | MRX | 9 hr |
| Sep 28, 9:53 AM EDT | Areal Flood Warning | MRX | 10 hr |
| Oct 2, 4:57 AM EDT | Dense Fog Advisory | MRX | 4 hr |
| Oct 2, 10:05 PM EDT | Dense Fog Advisory | MRX | 12 hr |
| Oct 5, 3:42 AM EDT | Dense Fog Advisory | MRX | 6 hr |
| Nov 13, 10:15 AM EST | Wind Advisory | MRX | 24 hr |
| Nov 20, 3:06 AM EST | Winter Weather Advisory | MRX | 3 days |
| Dec 2, 1:45 AM EST | Winter Weather Advisory | MRX | 29 hr |
| Dec 4, 3:39 AM EST | Wind Advisory | MRX | 33 hr |
| Dec 8, 3:03 PM EST | Wind Advisory | MRX | 22 hr |
| Dec 11, 3:56 AM EST | Winter Weather Advisory | MRX | 10 hr |
| Dec 13, 2:09 PM EST | Wind Advisory | MRX | 47 hr |
| Dec 19, 2:56 PM EST | Winter Storm Watch | MRX | 6 hr |
| Dec 19, 9:03 PM EST | Winter Weather Advisory | MRX | 37 hr |
| Dec 26, 1:45 PM EST | Wind Advisory | MRX | 40 hr |
| Dec 28, 5:30 AM EST | High Wind Warning | MRX | 38 hr |
| Dec 29, 8:10 AM EST | Special Weather Statement | MRX | 50 min |
| Dec 30, 2:37 PM EST | Wind Advisory | MRX | 28 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 | 5 |
| Severe Thunderstorm Watch | 2 |
| Mesoscale Discussion | 9 |
| Special Weather Statement | 14 |
| Flooding | |
| Areal Flood Warning | 4 |
| Flash Flood Warning | 7 |
| Flood Watch | 4 |
| Areal Flood Advisory | 5 |
| Winter | |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 2 |
| Winter Weather Advisory | 9 |
| Cold | |
| Wind Chill Warning | 1 |
| Wind Chill Watch | 1 |
| Frost Advisory | 2 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| High Wind Warning | 6 |
| High Wind Watch | 4 |
| Wind Advisory | 19 |
| Fog and smoke | |
| Dense Fog Advisory | 6 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20232025
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.