Alert archive / Montana / Jefferson County
Weather alerts in Jefferson County, Montana, 2025
118 weather alerts in 2025, 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 2025. Tap one for its archive.
- Alerts
- 118
- Warnings
- 25
- Watches
- 10
- Advisories
- 40
- Busiest month
- July24 alerts
- Busiest day
- July 26, 20255 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, 2025
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 6 | 2 | 67% | 3 | 0% | |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2025
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Great Falls, MT: tornado warnings | 2 | 0 | 100% | 0 | ||
| NWS Great Falls, MT: severe thunderstorm warnings | 165 | 54 | 67% | 192 | 55% | 24 min |
| NWS Great Falls, MT: flash flood warnings | 5 | 1 | 80% | 2 | 100% | 32 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, Mountain Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 2, 1:30 AM MST | Winter Weather Advisory | TFX | 55 hr |
| Jan 2, 12:47 PM MST | Winter Weather Advisory | TFX | 52 hr |
| Jan 4, 1:31 PM MST | Winter Weather Advisory | TFX | 45 hr |
| Jan 7, 5:05 PM MST | Dense Fog Advisory | TFX | 13 hr |
| Jan 9, 4:03 PM MST | Dense Fog Advisory | TFX | 10 hr |
| Jan 18, 2:38 AM MST | Cold Weather Advisory | TFX | 57 hr |
| Jan 19, 12:12 PM MST | Extreme Cold Warning | TFX | 24 hr |
| Jan 20, 12:52 PM MST | Cold Weather Advisory | TFX | 22 hr |
| Jan 23, 3:23 AM MST | Winter Weather Advisory | TFX | 42 hr |
| Jan 24, 3:44 AM MST | Cold Weather Advisory | TFX | 55 hr |
| Jan 25, 8:38 PM MST | Dense Fog Advisory | TFX | 15 hr |
| Jan 29, 1:30 PM MST | Winter Storm Watch | TFX | 5 days |
| Feb 1, 8:43 AM MST | Special Weather Statement | TFX | 32 min |
| Feb 1, 11:35 AM MST | Special Weather Statement | TFX | 40 min |
| Feb 1, 2:52 PM MST | Winter Weather Advisory | TFX | 43 hr |
| Feb 2, 1:45 AM MST | Cold Weather Advisory | TFX | 57 hr |
| Feb 2, 9:07 AM MST | Winter Storm Warning | TFX | 3 days |
| Feb 2, 1:51 PM MST | Winter Weather Advisory | TFX | 3 days |
| Feb 6, 1:26 AM MST | Winter Weather Advisory | TFX | 39 hr |
| Feb 7, 8:00 AM MST | Winter Storm Warning | TFX | 6 hr |
| Feb 9, 2:38 AM MST | Extreme Cold Warning | TFX | 56 hr |
| Feb 10, 1:59 AM MST | Cold Weather Advisory | TFX | 33 hr |
| Feb 11, 2:23 AM MST | Cold Weather Advisory | TFX | 33 hr |
| Feb 12, 1:17 AM MST | Cold Weather Advisory | TFX | 32 hr |
| Feb 12, 1:17 AM MST | Extreme Cold Warning | TFX | 32 hr |
| Feb 13, 1:04 PM MST | Winter Weather Advisory | TFX | 45 hr |
| Feb 15, 1:47 PM MST | Winter Storm Warning | TFX | 52 hr |
| Feb 15, 1:47 PM MST | Winter Weather Advisory | TFX | 3 days |
| Feb 25, 1:43 AM MST | Special Weather Statement | TFX | 47 min |
| Mar 14, 1:47 PM MDT | High Wind Watch | TFX | 30 hr |
| Mar 15, 2:54 AM MDT | High Wind Warning | TFX | 45 hr |
| Mar 15, 3:02 AM MDT | Winter Weather Advisory | TFX | 3 days |
| Mar 21, 2:05 AM MDT | High Wind Watch | TFX | 24 hr |
| Mar 28, 2:45 AM MDT | Winter Weather Advisory | TFX | 57 hr |
| Mar 29, 6:37 PM MDT | Special Weather Statement | TFX | 83 min |
| Mar 31, 2:55 AM MDT | Winter Storm Warning | TFX | 51 hr |
| Mar 31, 2:55 AM MDT | Winter Weather Advisory | TFX | 51 hr |
| Apr 11, 1:47 PM MDT | Winter Weather Advisory | TFX | 19 hr |
| Apr 15, 2:13 PM MDT | Winter Weather Advisory | TFX | 48 hr |
| Apr 17, 8:11 PM MDT | Special Weather Statement | TFX | 64 min |
| May 3, 1:21 PM MDT | Winter Weather Advisory | TFX | 62 hr |
| May 10, 2:26 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| May 10, 3:33 PM MDT | Special Weather Statement | TFX | 42 min |
| May 10, 4:00 PM MDT | Severe Thunderstorm Warning | TFX | 60 min |
| May 11, 12:39 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| May 11, 3:01 PM MDT | Special Weather Statement | TFX | 44 min |
| May 12, 3:12 AM MDT | Winter Weather Advisory | TFX | 30 hr |
| May 13, 2:39 AM MDT | Winter Weather Advisory | TFX | 33 hr |
| May 17, 1:43 PM MDT | Winter Weather Advisory | TFX | 28 hr |
| May 26, 2:14 PM MDT | Special Weather Statement | TFX | 31 min |
| May 29, 4:53 PM MDT | Special Weather Statement | TFX | 37 min |
| Jun 11, 1:57 PM MDT | Mesoscale Discussion | SPC | 63 min |
| Jun 13, 11:45 AM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 13, 11:49 AM MDT | Special Weather Statement | TFX | 26 min |
| Jun 13, 12:14 PM MDT | Special Weather Statement | TFX | 31 min |
| Jun 20, 3:14 AM MDT | Winter Weather Advisory | TFX | 57 hr |
| Jun 20, 12:32 PM MDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 20, 1:23 PM MDT | Special Weather Statement | TFX | 52 min |
| Jun 20, 2:12 PM MDT | Special Weather Statement | TFX | 48 min |
| Jun 26, 2:57 PM MDT | Special Weather Statement | TFX | 48 min |
| Jul 1, 2:31 PM MDT | Mesoscale Discussion | SPC | 89 min |
| Jul 1, 6:10 PM MDT | Special Weather Statement | TFX | 35 min |
| Jul 1, 7:32 PM MDT | Special Weather Statement | TFX | 43 min |
| Jul 2, 2:42 PM MDT | Mesoscale Discussion | SPC | 93 min |
| Jul 3, 3:00 PM MDT | Special Weather Statement | TFX | 45 min |
| Jul 4, 5:36 PM MDT | Special Weather Statement | TFX | 84 min |
| Jul 9, 1:48 PM MDT | Mesoscale Discussion | SPC | 87 min |
| Jul 21, 3:35 PM MDT | Special Weather Statement | TFX | 85 min |
| Jul 21, 5:17 PM MDT | Severe Thunderstorm Warning | TFX | 43 min |
| Jul 25, 4:41 PM MDT | Special Weather Statement | TFX | 49 min |
| Jul 25, 5:54 PM MDT | Special Weather Statement | TFX | 36 min |
| Jul 25, 6:30 PM MDT | Special Weather Statement | TFX | 45 min |
| Jul 25, 7:12 PM MDT | Special Weather Statement | TFX | 33 min |
| Jul 26, 2:01 PM MDT | Special Weather Statement | TFX | 44 min |
| Jul 26, 2:47 PM MDT | Special Weather Statement | TFX | 43 min |
| Jul 26, 4:05 PM MDT | Mesoscale Discussion | SPC | 115 min |
| Jul 27, 2:27 PM MDT | Special Weather Statement | TFX | 48 min |
| Jul 28, 1:16 PM MDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jul 28, 1:59 PM MDT | Special Weather Statement | TFX | 46 min |
| Jul 28, 2:39 PM MDT | Severe Thunderstorm Warning | TFX | 36 min |
| Jul 28, 3:04 PM MDT | Special Weather Statement | TFX | 26 min |
| Jul 29, 7:00 PM MDT | Areal Flood Advisory | TFX | 3 hr |
| Jul 29, 7:02 PM MDT | Special Weather Statement | TFX | 58 min |
| Jul 29, 7:15 PM MDT | Areal Flood Advisory | TFX | 5 hr |
| Jul 31, 7:22 PM MDT | Severe Thunderstorm Warning | TFX | 53 min |
| Aug 4, 4:33 PM MDT | Special Weather Statement | TFX | 42 min |
| Aug 4, 4:41 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 4, 4:49 PM MDT | Severe Thunderstorm Warning | TFX | 26 min |
| Aug 11, 12:26 PM MDT | Fire Weather Watch | MSO | 25 hr |
| Aug 12, 12:57 PM MDT | Fire Weather Watch | MSO | 24 hr |
| Aug 12, 12:57 PM MDT | Red Flag Warning | MSO | 33 hr |
| Aug 13, 12:33 PM MDT | Red Flag Warning | MSO | 32 hr |
| Aug 15, 2:34 AM MDT | Red Flag Warning | MSO | 18 hr |
| Aug 17, 1:23 PM MDT | Special Weather Statement | TFX | 67 min |
| Aug 17, 4:25 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 19, 2:04 PM MDT | Red Flag Warning | MSO | 32 hr |
| Aug 26, 2:53 AM MDT | Flash Flood Watch | TFX | 42 hr |
| Sep 14, 6:28 PM MDT | Special Weather Statement | TFX | 62 min |
| Sep 14, 7:20 PM MDT | Special Weather Statement | TFX | 40 min |
| Sep 14, 7:32 PM MDT | Severe Thunderstorm Warning | TFX | 43 min |
| Oct 11, 2:30 AM MDT | Winter Weather Advisory | TFX | 63 hr |
| Oct 23, 12:36 AM MDT | High Wind Watch | TFX | 50 hr |
| Oct 26, 2:08 PM MDT | Winter Weather Advisory | TFX | 20 hr |
| Nov 24, 10:12 AM MST | Snow Squall Warning | TFX | 48 min |
| Nov 24, 10:35 AM MST | Snow Squall Warning | TFX | 40 min |
| Nov 24, 11:36 AM MST | Snow Squall Warning | TFX | 39 min |
| Nov 26, 12:48 AM MST | Winter Weather Advisory | TFX | 9 hr |
| Nov 26, 11:59 PM MST | Winter Weather Advisory | TFX | 50 hr |
| Nov 30, 1:09 PM MST | Winter Weather Advisory | TFX | 64 hr |
| Dec 4, 1:46 PM MST | Winter Weather Advisory | TFX | 18 hr |
| Dec 5, 3:44 AM MST | Winter Weather Advisory | TFX | 41 hr |
| Dec 11, 12:59 PM MST | Winter Weather Advisory | TFX | 40 hr |
| Dec 14, 1:54 PM MST | High Wind Watch | TFX | 24 hr |
| Dec 15, 2:13 PM MST | High Wind Warning | TFX | 61 hr |
| Dec 18, 1:42 PM MST | High Wind Warning | TFX | 28 hr |
| Dec 21, 2:32 AM MST | Winter Weather Advisory | TFX | 32 hr |
| Dec 27, 12:00 PM MST | Snow Squall Warning | TFX | 60 min |
| Dec 27, 12:37 PM MST | Snow Squall Warning | TFX | 53 min |
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 | 6 |
| Severe Thunderstorm Watch | 2 |
| Mesoscale Discussion | 10 |
| Special Weather Statement | 33 |
| Flooding | |
| Flash Flood Watch | 1 |
| Areal Flood Advisory | 2 |
| Winter | |
| Snow Squall Warning | 5 |
| Winter Storm Warning | 4 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 28 |
| Cold | |
| Extreme Cold Warning | 3 |
| Cold Weather Advisory | 7 |
| Wind and dust | |
| High Wind Warning | 3 |
| High Wind Watch | 4 |
| Fire | |
| Red Flag Warning | 4 |
| Fire Weather Watch | 2 |
| Fog and smoke | |
| Dense Fog Advisory | 3 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20242026
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.