Alert archive / Tennessee / Knox County
Weather alerts in Knox County, Tennessee, 2011
190 weather alerts in 2011, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Knox County and its neighbors
Each county as a circle sized by its count in 2011. Tap one for its archive.
- Alerts
- 190
- Warnings
- 81
- Watches
- 33
- Advisories
- 40
- Busiest month
- April54 alerts
- Busiest day
- April 27, 201116 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 19 tornado warnings covering Knox County in 2011 had a tornado report inside them; 4 of 4 tornado reports fell inside a warning, on average 31 minutes after it went out.
Knox County, 2011
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 19 | 4 | 79% | 4 | 100% | 31 min |
| Severe thunderstorm warnings | 48 | 43 | 10% | 31 | 74% | 22 min |
| Flash flood warnings | 4 | 2 | 50% | 2 | 100% | 96 min |
Each office's whole area, 2011
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Morristown, TN: tornado warnings | 100 | 27 | 73% | 46 | 93% | 26 min |
| NWS Morristown, TN: severe thunderstorm warnings | 400 | 287 | 28% | 533 | 78% | 23 min |
| NWS Morristown, TN: flash flood warnings | 23 | 12 | 48% | 20 | 95% | 84 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 1, 8:35 AM EST | Areal Flood Advisory | MRX | 3 hr |
| Jan 6, 2:50 PM EST | Winter Weather Advisory | MRX | 49 hr |
| Jan 8, 3:30 AM EST | Winter Storm Watch | MRX | 36 hr |
| Jan 9, 3:20 PM EST | Winter Weather Advisory | MRX | 4 days |
| Jan 25, 3:14 PM EST | Winter Weather Advisory | MRX | 24 hr |
| Feb 1, 3:59 AM EST | Wind Advisory | MRX | 31 hr |
| Feb 9, 3:10 AM EST | Winter Weather Advisory | MRX | 24 hr |
| Feb 24, 2:16 PM EST | Wind Advisory | MRX | 25 hr |
| Feb 24, 11:59 PM EST | Severe Thunderstorm Watch | SPC | 5 hr |
| Feb 25, 1:48 AM EST | Mesoscale Discussion | SPC | 27 min |
| Feb 25, 1:50 AM EST | Severe Thunderstorm Warning | MRX | 40 min |
| Feb 25, 2:22 AM EST | Severe Thunderstorm Warning | MRX | 42 min |
| Feb 27, 8:21 PM EST | Dense Fog Advisory | MRX | 8 hr |
| Feb 28, 6:47 AM EST | Mesoscale Discussion | SPC | 28 min |
| Feb 28, 6:59 AM EST | Tornado Watch | SPC | 7 hr |
| Feb 28, 12:23 PM EST | Severe Thunderstorm Warning | MRX | 37 min |
| Feb 28, 12:25 PM EST | Mesoscale Discussion | SPC | 95 min |
| Feb 28, 12:48 PM EST | Tornado Warning | MRX | 42 min |
| Feb 28, 1:02 PM EST | Areal Flood Warning | MRX | 12 hr |
| Feb 28, 1:29 PM EST | Tornado Watch | SPC | 7 hr |
| Feb 28, 4:42 PM EST | Areal Flood Warning | MRX | 3 hr |
| Mar 5, 4:03 AM EST | Flood Watch | MRX | 35 hr |
| Mar 6, 4:36 AM EST | Areal Flood Advisory | MRX | 6 hr |
| Mar 8, 3:24 AM EST | Flood Watch | MRX | 36 hr |
| Mar 9, 9:12 AM EST | Areal Flood Advisory | MRX | 3 hr |
| Mar 9, 12:02 PM EST | Areal Flood Advisory | MRX | 3 hr |
| Mar 10, 2:14 AM EST | Areal Flood Advisory | MRX | 2 hr |
| Mar 10, 4:43 AM EST | Areal Flood Advisory | MRX | 2 hr |
| Mar 10, 6:41 AM EST | Areal Flood Warning | MRX | 3 hr |
| Mar 23, 3:41 PM EDT | Severe Thunderstorm Warning | MRX | 34 min |
| Mar 23, 3:45 PM EDT | Tornado Watch | SPC | 6 hr |
| Mar 23, 4:10 PM EDT | Severe Thunderstorm Warning | MRX | 39 min |
| Mar 23, 7:45 PM EDT | Severe Thunderstorm Warning | MRX | 60 min |
| Mar 23, 8:36 PM EDT | Severe Thunderstorm Warning | MRX | 54 min |
| Mar 23, 8:39 PM EDT | Mesoscale Discussion | SPC | 66 min |
| Mar 23, 9:00 PM EDT | Tornado Warning | MRX | 45 min |
| Mar 23, 9:41 PM EDT | Tornado Watch | SPC | 2 hr |
| Mar 26, 6:22 PM EDT | Mesoscale Discussion | SPC | 83 min |
| Mar 28, 3:17 PM EDT | Frost Advisory | MRX | 18 hr |
| Mar 31, 3:03 PM EDT | Freeze Warning | MRX | 18 hr |
| Apr 3, 4:13 AM EDT | Wind Advisory | MRX | 43 hr |
| Apr 4, 3:05 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Apr 4, 3:08 PM EDT | Mesoscale Discussion | SPC | 67 min |
| Apr 4, 4:49 PM EDT | Mesoscale Discussion | SPC | 56 min |
| Apr 4, 5:43 PM EDT | Severe Thunderstorm Warning | MRX | 62 min |
| Apr 4, 6:00 PM EDT | Mesoscale Discussion | SPC | 90 min |
| Apr 4, 6:03 PM EDT | Areal Flood Advisory | MRX | 117 min |
| Apr 4, 6:19 PM EDT | Areal Flood Advisory | MRX | 3 hr |
| Apr 4, 6:40 PM EDT | Severe Thunderstorm Warning | MRX | 35 min |
| Apr 5, 12:00 AM EDT | Areal Flood Advisory | MRX | 4 hr |
| Apr 8, 6:15 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Apr 8, 7:35 PM EDT | Mesoscale Discussion | SPC | 55 min |
| Apr 9, 12:34 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Apr 9, 2:00 PM EDT | Tornado Watch | SPC | 7 hr |
| Apr 9, 4:21 PM EDT | Mesoscale Discussion | SPC | 84 min |
| Apr 9, 5:22 PM EDT | Severe Thunderstorm Warning | MRX | 38 min |
| Apr 9, 6:05 PM EDT | Severe Thunderstorm Warning | MRX | 25 min |
| Apr 11, 3:47 AM EDT | Wind Advisory | MRX | 16 hr |
| Apr 11, 7:42 PM EDT | Mesoscale Discussion | SPC | 33 min |
| Apr 11, 8:08 PM EDT | Tornado Watch | SPC | 7 hr |
| Apr 12, 12:10 AM EDT | Severe Thunderstorm Warning | MRX | 45 min |
| Apr 15, 2:43 AM EDT | Wind Advisory | MRX | 27 hr |
| Apr 16, 2:03 AM EDT | Areal Flood Advisory | MRX | 3 hr |
| Apr 16, 10:46 AM EDT | Wind Advisory | MRX | 10 hr |
| Apr 20, 2:42 AM EDT | Tornado Watch | SPC | 5 hr |
| Apr 20, 3:20 AM EDT | Mesoscale Discussion | SPC | 85 min |
| Apr 25, 6:04 PM EDT | Severe Thunderstorm Warning | MRX | 41 min |
| Apr 25, 6:34 PM EDT | Severe Thunderstorm Warning | MRX | 41 min |
| Apr 26, 3:30 PM EDT | Wind Advisory | MRX | 35 hr |
| Apr 27, 8:34 AM EDT | Tornado Watch | SPC | 4 hr |
| Apr 27, 9:51 AM EDT | Severe Thunderstorm Warning | MRX | 54 min |
| Apr 27, 10:47 AM EDT | Tornado Warning | MRX | 18 min |
| Apr 27, 11:27 AM EDT | Tornado Watch | SPC | 6 hr |
| Apr 27, 3:22 PM EDT | Mesoscale Discussion | SPC | 83 min |
| Apr 27, 3:38 PM EDT | Tornado Warning | MRX | 52 min |
| Apr 27, 4:09 PM EDT | Tornado Warning | MRX | 51 min |
| Apr 27, 4:36 PM EDT | Tornado Watch | SPC | 8 hr |
| Apr 27, 4:39 PM EDT | Areal Flood Advisory | MRX | 3 hr |
| Apr 27, 4:56 PM EDT | Tornado Warning | MRX | 49 min |
| Apr 27, 5:45 PM EDT | Tornado Warning | MRX | 32 min |
| Apr 27, 6:38 PM EDT | Mesoscale Discussion | SPC | 97 min |
| Apr 27, 7:06 PM EDT | Tornado Warning | MRX | 54 min |
| Apr 27, 7:21 PM EDT | Tornado Warning | MRX | 39 min |
| Apr 27, 7:49 PM EDT | Tornado Warning | MRX | 41 min |
| Apr 27, 7:54 PM EDT | Tornado Warning | MRX | 51 min |
| Apr 27, 8:07 PM EDT | Tornado Warning | MRX | 53 min |
| Apr 27, 8:26 PM EDT | Flash Flood Warning | MRX | 3 hr |
| Apr 27, 8:29 PM EDT | Tornado Warning | MRX | 61 min |
| Apr 27, 8:48 PM EDT | Tornado Warning | MRX | 27 min |
| Apr 27, 10:03 PM EDT | Areal Flood Warning | MRX | 8 hr |
| Apr 27, 10:24 PM EDT | Tornado Warning | MRX | 51 min |
| Apr 27, 10:49 PM EDT | Tornado Warning | MRX | 26 min |
| Apr 27, 11:13 PM EDT | Tornado Warning | MRX | 47 min |
| Apr 27, 11:21 PM EDT | Tornado Warning | MRX | 24 min |
| May 4, 10:14 AM EDT | Frost Advisory | MRX | 23 hr |
| May 10, 3:20 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| May 13, 12:22 PM EDT | Mesoscale Discussion | SPC | 113 min |
| May 13, 1:10 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 22, 1:55 PM EDT | Mesoscale Discussion | SPC | 65 min |
| May 22, 2:18 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 22, 4:44 PM EDT | Mesoscale Discussion | SPC | 61 min |
| May 22, 5:07 PM EDT | Severe Thunderstorm Warning | MRX | 53 min |
| May 24, 6:24 AM EDT | Mesoscale Discussion | SPC | 96 min |
| May 24, 7:01 AM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| May 24, 8:34 AM EDT | Mesoscale Discussion | SPC | 116 min |
| May 24, 12:55 PM EDT | Mesoscale Discussion | SPC | 65 min |
| May 24, 1:57 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 24, 4:27 PM EDT | Mesoscale Discussion | SPC | 63 min |
| May 24, 5:33 PM EDT | Severe Thunderstorm Warning | MRX | 57 min |
| May 24, 6:33 PM EDT | Severe Thunderstorm Warning | MRX | 57 min |
| May 24, 7:46 PM EDT | Mesoscale Discussion | SPC | 59 min |
| May 26, 10:15 AM EDT | Severe Thunderstorm Watch | SPC | 9 hr |
| May 26, 11:41 AM EDT | Severe Thunderstorm Warning | MRX | 34 min |
| May 26, 12:18 PM EDT | Severe Thunderstorm Warning | MRX | 42 min |
| May 26, 1:02 PM EDT | Severe Thunderstorm Warning | MRX | 43 min |
| May 26, 2:03 PM EDT | Severe Thunderstorm Warning | MRX | 42 min |
| May 26, 2:46 PM EDT | Severe Thunderstorm Warning | MRX | 44 min |
| May 26, 5:10 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 7, 6:04 PM EDT | Mesoscale Discussion | SPC | 116 min |
| Jun 9, 1:10 PM EDT | Mesoscale Discussion | SPC | 95 min |
| Jun 11, 1:48 PM EDT | Mesoscale Discussion | SPC | 87 min |
| Jun 15, 12:52 PM EDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 15, 1:25 PM EDT | Severe Thunderstorm Warning | MRX | 65 min |
| Jun 15, 4:03 PM EDT | Areal Flood Advisory | MRX | 3 hr |
| Jun 15, 4:34 PM EDT | Mesoscale Discussion | SPC | 116 min |
| Jun 18, 9:38 AM EDT | Mesoscale Discussion | SPC | 97 min |
| Jun 18, 11:05 AM EDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 19, 8:51 AM EDT | Mesoscale Discussion | SPC | 114 min |
| Jun 19, 9:33 AM EDT | Areal Flood Advisory | MRX | 117 min |
| Jun 19, 11:17 AM EDT | Flash Flood Watch | MRX | 19 hr |
| Jun 19, 1:23 PM EDT | Mesoscale Discussion | SPC | 67 min |
| Jun 19, 1:52 PM EDT | Tornado Watch | SPC | 8 hr |
| Jun 19, 3:18 PM EDT | Severe Thunderstorm Warning | MRX | 42 min |
| Jun 19, 4:12 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 19, 7:18 PM EDT | Mesoscale Discussion | SPC | 57 min |
| Jun 19, 9:07 PM EDT | Mesoscale Discussion | SPC | 53 min |
| Jun 19, 9:41 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 21, 6:03 PM EDT | Mesoscale Discussion | SPC | 57 min |
| Jun 21, 7:56 PM EDT | Severe Thunderstorm Warning | MRX | 34 min |
| Jun 21, 8:13 PM EDT | Severe Thunderstorm Warning | MRX | 62 min |
| Jun 21, 8:16 PM EDT | Severe Thunderstorm Warning | MRX | 44 min |
| Jun 21, 8:43 PM EDT | Severe Thunderstorm Warning | MRX | 62 min |
| Jun 21, 8:48 PM EDT | Severe Thunderstorm Warning | MRX | 57 min |
| Jun 22, 6:17 PM EDT | Severe Thunderstorm Warning | MRX | 43 min |
| Jun 22, 7:01 PM EDT | Severe Thunderstorm Warning | MRX | 59 min |
| Jun 23, 7:28 PM EDT | Severe Thunderstorm Warning | MRX | 47 min |
| Jun 23, 8:05 PM EDT | Severe Thunderstorm Warning | MRX | 25 min |
| Jun 23, 8:24 PM EDT | Severe Thunderstorm Warning | MRX | 36 min |
| Jun 24, 12:37 AM EDT | Tornado Warning | MRX | 68 min |
| Jun 24, 1:38 AM EDT | Severe Thunderstorm Warning | MRX | 67 min |
| Jun 24, 1:56 AM EDT | Areal Flood Advisory | MRX | 3 hr |
| Jun 24, 2:36 AM EDT | Flash Flood Warning | MRX | 3 hr |
| Jun 24, 3:24 AM EDT | Severe Thunderstorm Warning | MRX | 51 min |
| Jun 24, 5:27 AM EDT | Areal Flood Warning | MRX | 3 hr |
| Jun 27, 4:17 PM EDT | Mesoscale Discussion | SPC | 88 min |
| Jul 4, 12:10 PM EDT | Mesoscale Discussion | SPC | 95 min |
| Jul 4, 12:50 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 11, 3:43 PM EDT | Heat Advisory | MRX | 28 hr |
| Jul 14, 9:32 PM EDT | Areal Flood Advisory | MRX | 3 hr |
| Jul 15, 12:35 AM EDT | Areal Flood Advisory | MRX | 3 hr |
| Aug 3, 10:01 AM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 3, 1:26 PM EDT | Mesoscale Discussion | SPC | 64 min |
| Aug 3, 11:33 PM EDT | Severe Thunderstorm Warning | MRX | 42 min |
| Aug 3, 11:48 PM EDT | Severe Thunderstorm Warning | MRX | 32 min |
| Aug 8, 1:29 PM EDT | Severe Thunderstorm Warning | MRX | 61 min |
| Aug 8, 2:11 PM EDT | Severe Thunderstorm Warning | MRX | 64 min |
| Aug 8, 2:29 PM EDT | Severe Thunderstorm Warning | MRX | 61 min |
| Aug 8, 6:43 PM EDT | Severe Thunderstorm Warning | MRX | 62 min |
| Aug 14, 1:12 PM EDT | Severe Thunderstorm Warning | MRX | 48 min |
| Aug 14, 2:49 PM EDT | Severe Thunderstorm Warning | MRX | 41 min |
| Aug 18, 10:26 PM EDT | Severe Thunderstorm Warning | MRX | 34 min |
| Aug 18, 10:39 PM EDT | Severe Thunderstorm Warning | MRX | 36 min |
| Sep 3, 6:13 PM EDT | Severe Thunderstorm Warning | MRX | 62 min |
| Sep 4, 3:13 AM EDT | Flash Flood Watch | MRX | 60 hr |
| Sep 5, 11:01 AM EDT | Areal Flood Advisory | MRX | 6 hr |
| Sep 5, 11:54 AM EDT | Flash Flood Warning | MRX | 6 hr |
| Sep 5, 12:45 PM EDT | Flash Flood Warning | MRX | 5 hr |
| Sep 5, 5:37 PM EDT | Areal Flood Warning | MRX | 12 hr |
| Sep 6, 4:59 AM EDT | Areal Flood Warning | MRX | 6 hr |
| Sep 22, 5:43 AM EDT | Dense Fog Advisory | MRX | 3 hr |
| Oct 20, 9:05 PM EDT | Frost Advisory | MRX | 7 hr |
| Oct 21, 3:56 AM EDT | Frost Advisory | MRX | 29 hr |
| Oct 29, 4:23 AM EDT | Freeze Warning | MRX | 30 hr |
| Nov 5, 3:07 AM EDT | Dense Fog Advisory | MRX | 8 hr |
| Nov 27, 4:26 AM EST | Flood Watch | MRX | 42 hr |
| Nov 28, 8:08 AM EST | Areal Flood Advisory | MRX | 3 hr |
| Nov 28, 11:35 AM EST | Areal Flood Advisory | MRX | 6 hr |
| Nov 28, 2:01 PM EST | Areal Flood Warning | MRX | 10 hr |
| Dec 26, 12:53 AM EST | Dense Fog Advisory | MRX | 7 hr |
| Dec 27, 3:23 AM EST | Wind Advisory | MRX | 15 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 | 48 |
| Tornado Warning | 19 |
| Severe Thunderstorm Watch | 16 |
| Tornado Watch | 11 |
| Mesoscale Discussion | 36 |
| Flooding | |
| Areal Flood Warning | 8 |
| Flash Flood Warning | 4 |
| Flash Flood Watch | 2 |
| Flood Watch | 3 |
| Areal Flood Advisory | 19 |
| Winter | |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 4 |
| Heat | |
| Heat Advisory | 1 |
| Cold | |
| Freeze Warning | 2 |
| Frost Advisory | 4 |
| Wind and dust | |
| Wind Advisory | 8 |
| 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 archive20102012
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.