Alert archive / Tennessee / Johnson County
Weather alerts in Johnson County, Tennessee, 2023
103 weather alerts in 2023, 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 2023. Tap one for its archive.
- Alerts
- 103
- Warnings
- 27
- Watches
- 19
- Advisories
- 33
- Busiest month
- July17 alerts
- Busiest day
- September 7, 20237 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 Johnson County in 2023 had a tornado report inside them.
Johnson County, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 2 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 11 | 9 | 18% | 3 | 67% | 24 min |
| Flash flood warnings | 1 | 0 | 100% | 0 |
Each office's whole area, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Morristown, TN: tornado warnings | 29 | 4 | 86% | 10 | 60% | 11 min |
| NWS Morristown, TN: severe thunderstorm warnings | 282 | 246 | 13% | 385 | 89% | 22 min |
| NWS Morristown, TN: flash flood warnings | 45 | 25 | 44% | 48 | 79% | 51 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 2, 4:13 AM EST | High Wind Watch | MRX | 11 hr |
| Jan 2, 3:19 PM EST | Wind Advisory | MRX | 39 hr |
| Jan 3, 4:47 PM EST | Special Weather Statement | MRX | 28 min |
| Jan 11, 3:11 PM EST | Winter Storm Watch | MRX | 13 hr |
| Jan 11, 3:18 PM EST | Wind Advisory | MRX | 28 hr |
| Jan 12, 3:44 AM EST | Winter Storm Warning | MRX | 57 hr |
| Jan 12, 2:07 PM EST | Severe Thunderstorm Warning | MRX | 53 min |
| Jan 17, 6:48 PM EST | Dense Fog Advisory | MRX | 16 hr |
| Jan 18, 4:10 AM EST | Wind Advisory | MRX | 39 hr |
| Jan 19, 6:57 PM EST | Wind Advisory | MRX | 9 hr |
| Jan 22, 4:29 AM EST | Wind Advisory | MRX | 11 hr |
| Jan 22, 4:29 AM EST | Winter Storm Watch | MRX | 11 hr |
| Jan 22, 3:13 PM EST | Winter Weather Advisory | MRX | 24 hr |
| Jan 23, 3:38 PM EST | High Wind Watch | MRX | 12 hr |
| Jan 24, 3:20 AM EST | High Wind Warning | MRX | 40 hr |
| Jan 30, 10:24 PM EST | Dense Fog Advisory | MRX | 12 hr |
| Feb 8, 3:32 AM EST | Wind Advisory | MRX | 39 hr |
| Feb 10, 3:24 PM EST | Winter Storm Watch | MRX | 12 hr |
| Feb 11, 3:51 AM EST | Winter Storm Warning | MRX | 41 hr |
| Feb 12, 2:58 AM EST | Mesoscale Discussion | SPC | 3 hr |
| Feb 14, 3:27 AM EST | High Wind Warning | MRX | 27 hr |
| Feb 21, 2:36 PM EST | Wind Advisory | MRX | 40 hr |
| Feb 26, 3:26 AM EST | Wind Advisory | MRX | 52 hr |
| Mar 2, 3:35 AM EST | High Wind Watch | MRX | 12 hr |
| Mar 2, 3:34 PM EST | High Wind Warning | MRX | 35 hr |
| Mar 3, 2:41 PM EST | Tornado Watch | SPC | 5 hr |
| Mar 16, 3:19 PM EDT | Wind Advisory | MRX | 23 hr |
| Mar 24, 3:54 AM EDT | High Wind Warning | MRX | 34 hr |
| Mar 24, 3:54 AM EDT | Wind Advisory | MRX | 11 hr |
| Mar 24, 3:54 AM EDT | Wind Advisory | MRX | 40 hr |
| Mar 25, 5:15 AM EDT | Severe Thunderstorm Warning | MRX | 43 min |
| Mar 30, 3:28 PM EDT | High Wind Watch | MRX | 12 hr |
| Mar 31, 3:05 AM EDT | High Wind Warning | MRX | 44 hr |
| Apr 16, 5:13 PM EDT | Special Weather Statement | MRX | 47 min |
| Apr 16, 6:03 PM EDT | Special Weather Statement | MRX | 27 min |
| Apr 21, 3:45 AM EDT | Wind Advisory | MRX | 26 hr |
| Apr 22, 3:55 AM EDT | Special Weather Statement | MRX | 50 min |
| Apr 22, 2:54 PM EDT | Freeze Watch | MRX | 12 hr |
| Apr 23, 3:00 AM EDT | Freeze Warning | MRX | 30 hr |
| Apr 24, 3:33 AM EDT | Freeze Watch | MRX | 8 hr |
| Apr 24, 11:59 AM EDT | Freeze Warning | MRX | 21 hr |
| Apr 27, 3:10 AM EDT | Wind Advisory | MRX | 24 hr |
| Apr 28, 3:20 PM EDT | Mesoscale Discussion | SPC | 85 min |
| May 1, 2:52 PM EDT | Wind Advisory | MRX | 12 hr |
| May 16, 4:03 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| May 16, 6:03 PM EDT | Severe Thunderstorm Warning | MRX | 57 min |
| May 16, 6:33 PM EDT | Special Weather Statement | MRX | 57 min |
| Jun 4, 6:18 PM EDT | Special Weather Statement | MRX | 42 min |
| Jun 8, 3:08 AM EDT | Dense Fog Advisory | MRX | 6 hr |
| Jul 1, 6:27 AM EDT | Severe Thunderstorm Warning | MRX | 78 min |
| Jul 2, 5:54 PM EDT | Mesoscale Discussion | SPC | 96 min |
| Jul 3, 3:55 PM EDT | Special Weather Statement | MRX | 50 min |
| Jul 14, 4:00 AM EDT | Areal Flood Advisory | MRX | 2 hr |
| Jul 14, 7:35 PM EDT | Areal Flood Advisory | MRX | 115 min |
| Jul 14, 7:36 PM EDT | Special Weather Statement | MRX | 24 min |
| Jul 15, 3:42 PM EDT | Special Weather Statement | MRX | 48 min |
| Jul 15, 3:56 PM EDT | Severe Thunderstorm Warning | MRX | 49 min |
| Jul 15, 4:22 PM EDT | Areal Flood Advisory | MRX | 5 hr |
| Jul 15, 4:42 PM EDT | Flash Flood Warning | MRX | 6 hr |
| Jul 15, 7:30 PM EDT | Special Weather Statement | MRX | 45 min |
| Jul 25, 4:20 PM EDT | Special Weather Statement | MRX | 40 min |
| Jul 29, 2:47 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Jul 29, 3:45 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jul 29, 4:53 PM EDT | Severe Thunderstorm Warning | MRX | 67 min |
| Jul 29, 5:33 PM EDT | Severe Thunderstorm Warning | MRX | 42 min |
| Jul 29, 5:56 PM EDT | Mesoscale Discussion | SPC | 94 min |
| Aug 7, 8:18 AM EDT | Mesoscale Discussion | SPC | 117 min |
| Aug 7, 11:17 AM EDT | Tornado Watch | SPC | 7 hr |
| Aug 12, 2:38 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 12, 5:33 PM EDT | Special Weather Statement | MRX | 42 min |
| Aug 14, 8:33 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 14, 10:42 PM EDT | Tornado Warning | MRX | 63 min |
| Aug 14, 11:56 PM EDT | Severe Thunderstorm Warning | MRX | 64 min |
| Aug 15, 12:52 AM EDT | Tornado Warning | MRX | 16 min |
| Aug 24, 1:08 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 26, 3:25 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 7, 2:25 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 7, 2:29 PM EDT | Special Weather Statement | MRX | 31 min |
| Sep 7, 3:27 PM EDT | Special Weather Statement | MRX | 33 min |
| Sep 7, 4:13 PM EDT | Areal Flood Advisory | MRX | 3 hr |
| Sep 7, 4:15 PM EDT | Severe Thunderstorm Warning | MRX | 60 min |
| Sep 7, 4:49 PM EDT | Severe Thunderstorm Warning | MRX | 56 min |
| Sep 7, 5:03 PM EDT | Areal Flood Advisory | MRX | 3 hr |
| Sep 8, 4:11 PM EDT | Areal Flood Advisory | MRX | 3 hr |
| Sep 12, 5:29 PM EDT | Severe Thunderstorm Warning | MRX | 46 min |
| Oct 14, 3:21 PM EDT | Wind Advisory | MRX | 15 hr |
| Oct 20, 2:39 PM EDT | Special Weather Statement | MRX | 66 min |
| Oct 22, 3:08 AM EDT | Frost Advisory | MRX | 31 hr |
| Oct 30, 3:42 AM EDT | Freeze Watch | MRX | 24 hr |
| Oct 31, 3:37 AM EDT | Freeze Warning | MRX | 30 hr |
| Nov 19, 3:21 AM EST | High Wind Watch | MRX | 25 hr |
| Nov 19, 3:03 PM EST | Fire Weather Watch | MRX | 13 hr |
| Nov 20, 3:54 AM EST | High Wind Warning | MRX | 36 hr |
| Nov 20, 4:12 AM EST | Red Flag Warning | MRX | 32 hr |
| Dec 2, 3:22 AM EST | Dense Fog Advisory | MRX | 8 hr |
| Dec 5, 3:39 AM EST | Winter Weather Advisory | MRX | 33 hr |
| Dec 9, 6:41 AM EST | Wind Advisory | MRX | 22 hr |
| Dec 10, 4:55 AM EST | Winter Weather Advisory | MRX | 28 hr |
| Dec 16, 3:06 AM EST | Wind Advisory | MRX | 27 hr |
| Dec 17, 2:34 PM EST | Winter Weather Advisory | MRX | 37 hr |
| Dec 23, 3:04 PM EST | High Wind Watch | MRX | 12 hr |
| Dec 24, 2:52 AM EST | High Wind Warning | MRX | 49 hr |
| Dec 29, 10:25 AM EST | Winter Weather Advisory | MRX | 30 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 | 2 |
| Mesoscale Discussion | 9 |
| Special Weather Statement | 15 |
| Flooding | |
| Flash Flood Warning | 1 |
| Areal Flood Advisory | 6 |
| Winter | |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 3 |
| Winter Weather Advisory | 5 |
| Cold | |
| Freeze Warning | 3 |
| Freeze Watch | 3 |
| Frost Advisory | 1 |
| Wind and dust | |
| High Wind Warning | 7 |
| High Wind Watch | 6 |
| Wind Advisory | 17 |
| Fire | |
| Red Flag Warning | 1 |
| Fire Weather Watch | 1 |
| Fog and smoke | |
| Dense Fog Advisory | 4 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20222024
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.