Alert archive / Montana / Jefferson County
Weather alerts in Jefferson County, Montana, 2024
108 weather alerts in 2024, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Jefferson County and its neighbors
Each county as a circle sized by its count in 2024. Tap one for its archive.
- Alerts
- 108
- Warnings
- 35
- Watches
- 20
- Advisories
- 22
- Busiest month
- August30 alerts
- Busiest day
- August 23, 20248 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Jefferson County, 2024
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 5 | 3 | 40% | 2 | 50% | 9 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2024
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Great Falls, MT: severe thunderstorm warnings | 139 | 54 | 61% | 152 | 57% | 19 min |
| NWS Great Falls, MT: flash flood warnings | 2 | 0 | 100% | 1 | 0% |
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, Mountain Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 6, 1:38 PM MST | High Wind Watch | TFX | 3 days |
| Jan 9, 11:53 AM MST | Snow Squall Warning | TFX | 37 min |
| Jan 9, 12:01 PM MST | Snow Squall Warning | TFX | 59 min |
| Jan 9, 12:15 PM MST | Snow Squall Warning | TFX | 9 min |
| Jan 10, 12:55 AM MST | Wind Chill Warning | TFX | 5 days |
| Jan 10, 12:55 AM MST | Wind Chill Advisory | TFX | 6 days |
| Jan 10, 2:05 PM MST | Winter Weather Advisory | TFX | 44 hr |
| Jan 16, 2:41 AM MST | Winter Storm Warning | TFX | 56 hr |
| Jan 16, 2:58 PM MST | Winter Weather Advisory | TFX | 44 hr |
| Jan 17, 3:22 AM MST | Wind Chill Advisory | TFX | 57 hr |
| Jan 19, 2:37 PM MST | Winter Weather Advisory | TFX | 44 hr |
| Feb 1, 1:28 PM MST | Winter Weather Advisory | TFX | 70 hr |
| Feb 2, 3:22 AM MST | Winter Storm Warning | TFX | 58 hr |
| Feb 6, 2:44 AM MST | Winter Weather Advisory | TFX | 4 days |
| Feb 13, 12:58 PM MST | Winter Weather Advisory | TFX | 64 hr |
| Feb 14, 2:14 AM MST | Winter Storm Warning | TFX | 51 hr |
| Feb 16, 8:42 PM MST | Wind Chill Advisory | TFX | 12 hr |
| Feb 23, 2:57 AM MST | High Wind Watch | TFX | 33 hr |
| Feb 24, 12:03 PM MST | High Wind Warning | TFX | 53 hr |
| Feb 24, 1:35 PM MST | Winter Weather Advisory | TFX | 57 hr |
| Feb 26, 5:01 PM MST | High Wind Warning | TFX | 77 min |
| Feb 27, 2:19 AM MST | High Wind Warning | TFX | 3 days |
| Feb 27, 2:53 PM MST | High Wind Watch | TFX | 35 hr |
| Mar 22, 1:29 PM MDT | Winter Weather Advisory | TFX | 68 hr |
| Mar 23, 5:57 PM MDT | Special Weather Statement | TFX | 48 min |
| Apr 25, 1:46 AM MDT | Winter Weather Advisory | TFX | 59 hr |
| Apr 30, 8:25 PM MDT | Special Weather Statement | TFX | 20 min |
| May 5, 2:00 PM MDT | High Wind Warning | TFX | 64 hr |
| May 6, 2:07 PM MDT | Winter Weather Advisory | TFX | 46 hr |
| May 20, 1:46 AM MDT | Winter Storm Watch | TFX | 37 hr |
| May 21, 2:42 PM MDT | Winter Storm Warning | TFX | 50 hr |
| May 21, 2:42 PM MDT | Winter Weather Advisory | TFX | 47 hr |
| May 28, 1:13 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| May 28, 6:31 PM MDT | Severe Thunderstorm Warning | TFX | 31 min |
| Jun 1, 7:30 PM MDT | Special Weather Statement | TFX | 45 min |
| Jun 13, 1:59 PM MDT | Winter Storm Watch | TFX | 60 hr |
| Jun 16, 2:25 AM MDT | Winter Weather Advisory | TFX | 58 hr |
| Jun 20, 1:38 PM MDT | Mesoscale Discussion | SPC | 67 min |
| Jun 26, 7:50 PM MDT | Special Weather Statement | TFX | 25 min |
| Jun 26, 8:12 PM MDT | Special Weather Statement | TFX | 63 min |
| Jun 30, 2:12 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 30, 8:41 PM MDT | Special Weather Statement | MSO | 34 min |
| Jul 11, 2:03 PM MDT | Fire Weather Watch | MSO | 21 hr |
| Jul 11, 2:33 PM MDT | Fire Weather Watch | TFX | 22 hr |
| Jul 12, 10:37 AM MDT | Red Flag Warning | MSO | 34 hr |
| Jul 12, 12:07 PM MDT | Red Flag Warning | TFX | 36 hr |
| Jul 21, 3:04 PM MDT | Fire Weather Watch | TFX | 71 hr |
| Jul 22, 1:26 PM MDT | Fire Weather Watch | MSO | 25 hr |
| Jul 22, 2:35 PM MDT | Red Flag Warning | TFX | 3 days |
| Jul 23, 2:56 AM MDT | Fire Weather Watch | TFX | 12 hr |
| Jul 23, 2:18 PM MDT | Red Flag Warning | MSO | 31 hr |
| Jul 24, 1:27 PM MDT | Red Flag Warning | MSO | 32 hr |
| Jul 24, 2:23 PM MDT | Red Flag Warning | TFX | 30 hr |
| Aug 6, 3:20 PM MDT | Special Weather Statement | TFX | 40 min |
| Aug 6, 3:57 PM MDT | Special Weather Statement | TFX | 48 min |
| Aug 6, 3:59 PM MDT | Special Weather Statement | MSO | 31 min |
| Aug 6, 4:32 PM MDT | Special Weather Statement | TFX | 43 min |
| Aug 6, 5:01 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 6, 5:34 PM MDT | Special Weather Statement | TFX | 41 min |
| Aug 10, 1:24 PM MDT | Special Weather Statement | TFX | 51 min |
| Aug 10, 1:50 PM MDT | Severe Thunderstorm Warning | TFX | 40 min |
| Aug 10, 2:13 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 15, 6:55 PM MDT | Special Weather Statement | TFX | 50 min |
| Aug 18, 5:06 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 19, 2:21 PM MDT | Mesoscale Discussion | SPC | 84 min |
| Aug 19, 2:48 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 19, 4:50 PM MDT | Special Weather Statement | TFX | 55 min |
| Aug 19, 5:51 PM MDT | Severe Thunderstorm Warning | TFX | 24 min |
| Aug 19, 6:05 PM MDT | Mesoscale Discussion | SPC | 115 min |
| Aug 20, 2:11 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 20, 2:39 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 23, 6:39 AM MDT | Red Flag Warning | TFX | 15 hr |
| Aug 23, 7:04 AM MDT | Red Flag Warning | MSO | 13 hr |
| Aug 23, 7:09 AM MDT | High Wind Warning | TFX | 12 hr |
| Aug 23, 2:13 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 23, 2:54 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 23, 3:33 PM MDT | Special Weather Statement | TFX | 42 min |
| Aug 23, 4:09 PM MDT | Severe Thunderstorm Warning | TFX | 36 min |
| Aug 23, 5:04 PM MDT | Mesoscale Discussion | SPC | 116 min |
| Aug 26, 10:39 AM MDT | Red Flag Warning | MSO | 34 hr |
| Aug 26, 12:41 PM MDT | Red Flag Warning | TFX | 32 hr |
| Aug 31, 1:20 PM MDT | Fire Weather Watch | MSO | 24 hr |
| Aug 31, 2:11 PM MDT | Fire Weather Watch | TFX | 23 hr |
| Sep 1, 1:03 PM MDT | Red Flag Warning | MSO | 33 hr |
| Sep 1, 1:15 PM MDT | Red Flag Warning | TFX | 33 hr |
| Sep 3, 12:07 PM MDT | Mesoscale Discussion | SPC | 113 min |
| Sep 3, 12:54 PM MDT | Special Weather Statement | TFX | 51 min |
| Sep 11, 2:26 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 11, 5:08 PM MDT | Special Weather Statement | TFX | 52 min |
| Sep 11, 5:27 PM MDT | Special Weather Statement | TFX | 33 min |
| Sep 11, 5:55 PM MDT | Severe Thunderstorm Warning | TFX | 35 min |
| Sep 16, 2:36 PM MDT | Special Weather Statement | TFX | 24 min |
| Sep 28, 10:54 AM MDT | Red Flag Warning | MSO | 34 hr |
| Oct 2, 12:57 AM MDT | High Wind Watch | TFX | 37 hr |
| Oct 2, 12:49 PM MDT | Fire Weather Watch | MSO | 23 hr |
| Oct 3, 2:00 AM MDT | Fire Weather Watch | TFX | 12 hr |
| Oct 3, 11:31 AM MDT | Red Flag Warning | MSO | 34 hr |
| Oct 3, 1:34 PM MDT | High Wind Warning | TFX | 37 hr |
| Oct 3, 1:51 PM MDT | Red Flag Warning | TFX | 35 hr |
| Oct 15, 1:11 PM MDT | Winter Weather Advisory | TFX | 68 hr |
| Nov 3, 1:57 PM MST | Winter Weather Advisory | TFX | 60 hr |
| Nov 14, 2:52 AM MST | Winter Weather Advisory | TFX | 53 hr |
| Nov 21, 12:34 PM MST | Winter Weather Advisory | TFX | 70 hr |
| Nov 25, 2:15 AM MST | Dense Fog Advisory | TFX | 8 hr |
| Dec 13, 1:30 PM MST | Winter Weather Advisory | TFX | 48 hr |
| Dec 16, 1:26 PM MST | High Wind Watch | TFX | 37 hr |
| Dec 17, 9:38 AM MST | High Wind Warning | TFX | 40 hr |
| Dec 25, 1:26 PM MST | Winter Weather Advisory | TFX | 5 days |
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 | 4 |
| Mesoscale Discussion | 12 |
| Special Weather Statement | 19 |
| Winter | |
| Snow Squall Warning | 3 |
| Winter Storm Warning | 4 |
| Winter Storm Watch | 2 |
| Winter Weather Advisory | 18 |
| Cold | |
| Wind Chill Warning | 1 |
| Wind Chill Advisory | 3 |
| Wind and dust | |
| High Wind Warning | 7 |
| High Wind Watch | 5 |
| Fire | |
| Red Flag Warning | 15 |
| Fire Weather Watch | 9 |
| Fog and smoke | |
| Dense Fog Advisory | 1 |
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.