Alert archive / Montana / Severe Thunderstorm Warnings
Severe Thunderstorm Warnings in Montana, 2020
221 severe thunderstorm warnings in 2020. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of severe thunderstorm warnings reaches back to 1986.
Severe Thunderstorm Warnings by county
Each county as a circle sized by its count in 2020. Tap one for its archive.
- Severe Thunderstorm Warnings
- 221
- Busiest month
- July107 severe thunderstorm warnings
- Busiest day
- July 7, 202030 severe thunderstorm warnings
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
119 of 221 severe thunderstorm warnings covering Montana in 2020 had a qualifying storm report inside them; 274 of 453 hail, wind and damage reports fell inside a warning, on average 23 minutes after it went out.
Montana, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Severe thunderstorm warnings | 221 | 119 | 46% | 453 | 60% | 23 min |
Each office's whole area, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Great Falls, MT: severe thunderstorm warnings | 65 | 27 | 58% | 108 | 44% | 14 min |
| NWS Missoula, MT: severe thunderstorm warnings | 7 | 5 | 29% | 29 | 69% | 12 min |
| NWS Billings, MT: severe thunderstorm warnings | 71 | 41 | 42% | 143 | 55% | 29 min |
| NWS Glasgow, MT: severe thunderstorm warnings | 79 | 46 | 42% | 174 | 74% | 25 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 | Counties | Lasted |
|---|---|---|---|---|
| May 3, 4:32 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 58 min |
| May 3, 5:26 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 64 min |
| May 3, 6:04 PM MDT | Severe Thunderstorm Warning | GGW | Wibaux | 22 min |
| May 3, 6:28 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 62 min |
| May 18, 6:50 PM MDT | Severe Thunderstorm Warning | TFX | Lewis and Clark | 25 min |
| May 18, 7:12 PM MDT | Severe Thunderstorm Warning | TFX | Cascade, Lewis and Clark | 33 min |
| May 18, 7:37 PM MDT | Severe Thunderstorm Warning | TFX | Cascade, Lewis and Clark, Teton | 23 min |
| May 18, 7:53 PM MDT | Severe Thunderstorm Warning | TFX | Cascade, Teton | 26 min |
| May 18, 11:44 PM MDT | Severe Thunderstorm Warning | TFX | Chouteau, Fergus, Judith Basin | 46 min |
| May 19, 4:39 PM MDT | Severe Thunderstorm Warning | TFX | Cascade, Judith Basin | 36 min |
| May 19, 5:15 PM MDT | Severe Thunderstorm Warning | TFX | Judith Basin | 30 min |
| May 19, 7:24 PM MDT | Severe Thunderstorm Warning | BYZ | Wheatland | 66 min |
| May 19, 8:01 PM MDT | Severe Thunderstorm Warning | BYZ | Golden Valley | 59 min |
| May 19, 8:19 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 26 min |
| May 19, 8:47 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 28 min |
| May 19, 8:55 PM MDT | Severe Thunderstorm Warning | BYZ | Musselshell | 35 min |
| May 19, 8:59 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 61 min |
| May 19, 9:25 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 35 min |
| May 20, 12:55 AM MDT | Severe Thunderstorm Warning | BYZ | Golden Valley, Musselshell | 50 min |
| May 20, 2:00 AM MDT | Severe Thunderstorm Warning | TFX | Cascade, Chouteau, Pondera, Teton | 45 min |
| May 20, 2:26 AM MDT | Severe Thunderstorm Warning | GGW | Petroleum | 49 min |
| May 20, 4:21 PM MDT | Severe Thunderstorm Warning | BYZ | Custer | 24 min |
| May 20, 4:42 PM MDT | Severe Thunderstorm Warning | BYZ | Custer | 48 min |
| May 20, 5:23 PM MDT | Severe Thunderstorm Warning | BYZ | Custer | 67 min |
| May 20, 6:23 PM MDT | Severe Thunderstorm Warning | BYZ | Custer | 52 min |
| May 20, 6:54 PM MDT | Severe Thunderstorm Warning | BYZ | Custer, Rosebud | 36 min |
| May 20, 6:55 PM MDT | Severe Thunderstorm Warning | GGW | Prairie | 30 min |
| May 20, 7:24 PM MDT | Severe Thunderstorm Warning | BYZ | Custer, Fallon, Rosebud | 48 min |
| May 20, 7:28 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, Garfield, McCone, Prairie | 62 min |
| May 20, 7:35 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, Petroleum, Phillips | 55 min |
| May 20, 8:18 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, McCone, Prairie, Valley | 57 min |
| May 20, 8:36 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, McCone, Richland, Roosevelt, Wibaux | 39 min |
| May 20, 8:44 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, Garfield, McCone, Phillips, Richland, Roosevelt and 1 more | 76 min |
| May 20, 9:33 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Phillips, Roosevelt, Valley | 57 min |
| May 20, 9:35 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Roosevelt, Sheridan | 55 min |
| May 31, 8:14 AM MDT | Severe Thunderstorm Warning | MSO | Flathead, Lake, Lincoln | 31 min |
| May 31, 8:41 AM MDT | Severe Thunderstorm Warning | MSO | Flathead, Lincoln | 34 min |
| May 31, 5:10 PM MDT | Severe Thunderstorm Warning | BYZ | Custer | 65 min |
| May 31, 5:23 PM MDT | Severe Thunderstorm Warning | GGW | Prairie | 53 min |
| May 31, 6:00 PM MDT | Severe Thunderstorm Warning | BYZ | Carter, Custer, Powder River | 45 min |
| May 31, 6:18 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 42 min |
| May 31, 6:31 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, McCone | 59 min |
| May 31, 6:43 PM MDT | Severe Thunderstorm Warning | BYZ | Fallon | 45 min |
| May 31, 6:44 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 61 min |
| May 31, 6:58 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 47 min |
| May 31, 7:24 PM MDT | Severe Thunderstorm Warning | GGW | McCone | 41 min |
| Jun 4, 3:49 PM MDT | Severe Thunderstorm Warning | BYZ | Carter, Powder River | 56 min |
| Jun 5, 7:36 PM MDT | Severe Thunderstorm Warning | TFX | Cascade, Meagher | 24 min |
| Jun 6, 2:08 AM MDT | Severe Thunderstorm Warning | GGW | Daniels, Valley | 53 min |
| Jun 6, 4:26 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, McCone, Prairie | 30 min |
| Jun 6, 6:05 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 55 min |
| Jun 6, 6:43 PM MDT | Severe Thunderstorm Warning | TFX | Gallatin | 47 min |
| Jun 7, 6:33 PM MDT | Severe Thunderstorm Warning | BYZ | Carter, Fallon | 57 min |
| Jun 13, 5:53 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, Valley | 67 min |
| Jun 13, 6:58 PM MDT | Severe Thunderstorm Warning | GGW | Valley | 62 min |
| Jun 13, 7:41 PM MDT | Severe Thunderstorm Warning | TFX | Hill, Liberty | 34 min |
| Jun 13, 8:09 PM MDT | Severe Thunderstorm Warning | TFX | Hill, Liberty | 4 min |
| Jun 13, 8:16 PM MDT | Severe Thunderstorm Warning | TFX | Hill, Liberty | 14 min |
| Jun 13, 8:50 PM MDT | Severe Thunderstorm Warning | GGW | Phillips | 55 min |
| Jun 24, 3:56 PM MDT | Severe Thunderstorm Warning | MSO | Lake, Missoula | 34 min |
| Jun 24, 4:12 PM MDT | Severe Thunderstorm Warning | MSO | Flathead | 48 min |
| Jun 24, 4:42 PM MDT | Severe Thunderstorm Warning | MSO | Flathead | 36 min |
| Jun 24, 6:38 PM MDT | Severe Thunderstorm Warning | TFX | Broadwater, Gallatin, Jefferson, Madison | 33 min |
| Jun 24, 7:26 PM MDT | Severe Thunderstorm Warning | TFX | Chouteau, Teton | 34 min |
| Jun 24, 7:44 PM MDT | Severe Thunderstorm Warning | TFX | Chouteau, Teton | 31 min |
| Jun 27, 2:44 PM MDT | Severe Thunderstorm Warning | TFX | Blaine, Hill | 31 min |
| Jun 27, 8:04 PM MDT | Severe Thunderstorm Warning | GGW | Valley | 26 min |
| Jun 27, 8:55 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Valley | 29 min |
| Jun 29, 3:35 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, Wibaux | 55 min |
| Jun 29, 4:31 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, Richland, Wibaux | 59 min |
| Jun 29, 8:12 PM MDT | Severe Thunderstorm Warning | GGW | Sheridan | 63 min |
| Jul 3, 4:04 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn, Yellowstone | 41 min |
| Jul 3, 4:44 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn, Treasure | 15 min |
| Jul 3, 4:57 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 48 min |
| Jul 3, 5:05 PM MDT | Severe Thunderstorm Warning | BYZ | Carter, Powder River | 55 min |
| Jul 3, 5:27 PM MDT | Severe Thunderstorm Warning | BYZ | Carter, Powder River | 33 min |
| Jul 3, 5:44 PM MDT | Severe Thunderstorm Warning | TFX | Blaine, Fergus | 31 min |
| Jul 3, 5:59 PM MDT | Severe Thunderstorm Warning | BYZ | Carter, Powder River | 61 min |
| Jul 3, 6:11 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, McCone | 64 min |
| Jul 3, 6:48 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, McCone | 42 min |
| Jul 3, 6:54 PM MDT | Severe Thunderstorm Warning | TFX | Cascade, Chouteau, Judith Basin | 39 min |
| Jul 3, 6:59 PM MDT | Severe Thunderstorm Warning | BYZ | Custer | 21 min |
| Jul 3, 7:04 PM MDT | Severe Thunderstorm Warning | GGW | McCone | 56 min |
| Jul 3, 7:07 PM MDT | Severe Thunderstorm Warning | TFX | Cascade, Chouteau | 53 min |
| Jul 3, 7:24 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, McCone | 51 min |
| Jul 3, 8:06 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, Wibaux | 43 min |
| Jul 4, 3:33 PM MDT | Severe Thunderstorm Warning | TFX | Pondera, Teton | 27 min |
| Jul 4, 3:39 PM MDT | Severe Thunderstorm Warning | TFX | Cascade | 25 min |
| Jul 4, 5:14 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn, Rosebud | 46 min |
| Jul 4, 5:57 PM MDT | Severe Thunderstorm Warning | BYZ | Powder River, Rosebud | 48 min |
| Jul 4, 6:02 PM MDT | Severe Thunderstorm Warning | BYZ | Rosebud | 43 min |
| Jul 4, 6:05 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 40 min |
| Jul 4, 7:13 PM MDT | Severe Thunderstorm Warning | BYZ | Powder River | 47 min |
| Jul 4, 7:23 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, Petroleum, Phillips | 53 min |
| Jul 4, 7:58 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, Phillips, Valley | 62 min |
| Jul 4, 8:08 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, McCone | 52 min |
| Jul 4, 8:23 PM MDT | Severe Thunderstorm Warning | GGW | Daniels | 67 min |
| Jul 4, 8:31 PM MDT | Severe Thunderstorm Warning | GGW | McCone, Valley | 37 min |
| Jul 4, 8:52 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, McCone, Valley | 53 min |
| Jul 4, 9:12 PM MDT | Severe Thunderstorm Warning | GGW | Valley | 36 min |
| Jul 4, 9:33 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, McCone, Roosevelt, Valley | 57 min |
| Jul 4, 10:45 PM MDT | Severe Thunderstorm Warning | GGW | Richland, Roosevelt, Sheridan | 48 min |
| Jul 5, 4:09 PM MDT | Severe Thunderstorm Warning | GGW | Roosevelt | 35 min |
| Jul 5, 5:42 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 17 min |
| Jul 6, 1:34 PM MDT | Severe Thunderstorm Warning | GGW | McCone | 28 min |
| Jul 6, 2:23 PM MDT | Severe Thunderstorm Warning | BYZ | Musselshell | 37 min |
| Jul 6, 2:54 PM MDT | Severe Thunderstorm Warning | BYZ | Rosebud, Treasure | 66 min |
| Jul 6, 3:32 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, McCone, Richland, Roosevelt | 58 min |
| Jul 6, 3:55 PM MDT | Severe Thunderstorm Warning | BYZ | Rosebud | 65 min |
| Jul 6, 4:10 PM MDT | Severe Thunderstorm Warning | BYZ | Powder River | 65 min |
| Jul 6, 4:18 PM MDT | Severe Thunderstorm Warning | GGW | McCone | 57 min |
| Jul 6, 4:29 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Valley | 61 min |
| Jul 6, 4:47 PM MDT | Severe Thunderstorm Warning | BYZ | Custer | 43 min |
| Jul 6, 5:13 PM MDT | Severe Thunderstorm Warning | BYZ | Carter, Custer, Fallon | 47 min |
| Jul 6, 5:14 PM MDT | Severe Thunderstorm Warning | BYZ | Carter, Powder River | 25 min |
| Jul 6, 5:28 PM MDT | Severe Thunderstorm Warning | BYZ | Custer, Powder River | 32 min |
| Jul 6, 5:58 PM MDT | Severe Thunderstorm Warning | BYZ | Carter, Custer, Powder River | 24 min |
| Jul 6, 5:58 PM MDT | Severe Thunderstorm Warning | GGW | Phillips | 34 min |
| Jul 6, 5:59 PM MDT | Severe Thunderstorm Warning | BYZ | Fallon | 46 min |
| Jul 6, 6:02 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 22 min |
| Jul 7, 1:27 PM MDT | Severe Thunderstorm Warning | TFX | Gallatin | 33 min |
| Jul 7, 1:28 PM MDT | Severe Thunderstorm Warning | TFX | Broadwater, Gallatin, Meagher | 32 min |
| Jul 7, 1:43 PM MDT | Severe Thunderstorm Warning | TFX | Chouteau | 47 min |
| Jul 7, 1:44 PM MDT | Severe Thunderstorm Warning | BYZ | Park, Sweet Grass | 61 min |
| Jul 7, 1:56 PM MDT | Severe Thunderstorm Warning | TFX | Meagher | 18 min |
| Jul 7, 2:02 PM MDT | Severe Thunderstorm Warning | BYZ | Wheatland | 43 min |
| Jul 7, 2:04 PM MDT | Severe Thunderstorm Warning | TFX | Gallatin, Madison | 26 min |
| Jul 7, 2:13 PM MDT | Severe Thunderstorm Warning | TFX | Hill, Liberty | 47 min |
| Jul 7, 2:31 PM MDT | Severe Thunderstorm Warning | TFX | Blaine, Chouteau, Hill | 59 min |
| Jul 7, 2:43 PM MDT | Severe Thunderstorm Warning | BYZ | Golden Valley, Wheatland | 38 min |
| Jul 7, 2:43 PM MDT | Severe Thunderstorm Warning | TFX | Chouteau, Fergus, Judith Basin | 32 min |
| Jul 7, 3:13 PM MDT | Severe Thunderstorm Warning | TFX | Blaine, Chouteau, Fergus, Judith Basin | 32 min |
| Jul 7, 3:42 PM MDT | Severe Thunderstorm Warning | BYZ | Golden Valley, Musselshell, Stillwater | 63 min |
| Jul 7, 3:44 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 46 min |
| Jul 7, 3:47 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, Petroleum, Phillips | 58 min |
| Jul 7, 4:07 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn, Rosebud | 53 min |
| Jul 7, 4:14 PM MDT | Severe Thunderstorm Warning | TFX | Blaine | 46 min |
| Jul 7, 4:21 PM MDT | Severe Thunderstorm Warning | TFX | Blaine | 9 min |
| Jul 7, 4:33 PM MDT | Severe Thunderstorm Warning | GGW | Phillips | 57 min |
| Jul 7, 4:38 PM MDT | Severe Thunderstorm Warning | TFX | Blaine | 21 min |
| Jul 7, 4:44 PM MDT | Severe Thunderstorm Warning | BYZ | Musselshell, Rosebud | 61 min |
| Jul 7, 4:46 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, Petroleum, Phillips, Valley | 59 min |
| Jul 7, 4:52 PM MDT | Severe Thunderstorm Warning | BYZ | Custer, Powder River, Rosebud | 53 min |
| Jul 7, 4:56 PM MDT | Severe Thunderstorm Warning | TFX | Blaine | 17 min |
| Jul 7, 5:07 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn, Yellowstone | 38 min |
| Jul 7, 5:12 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Phillips, Roosevelt, Valley | 63 min |
| Jul 7, 5:25 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, Garfield, McCone, Petroleum, Phillips, Prairie and 2 more | 65 min |
| Jul 7, 5:41 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn, Rosebud, Treasure, Yellowstone | 64 min |
| Jul 7, 5:43 PM MDT | Severe Thunderstorm Warning | BYZ | Custer, Powder River | 62 min |
| Jul 7, 6:13 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Roosevelt, Sheridan, Valley | 62 min |
| Jul 7, 6:27 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, Garfield, McCone, Prairie, Richland, Roosevelt and 2 more | 63 min |
| Jul 7, 6:40 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, Garfield, Prairie, Wibaux | 65 min |
| Jul 7, 6:42 PM MDT | Severe Thunderstorm Warning | BYZ | Carter, Custer, Fallon, Powder River | 63 min |
| Jul 7, 7:04 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Roosevelt, Sheridan | 56 min |
| Jul 7, 7:17 PM MDT | Severe Thunderstorm Warning | BYZ | Custer | 43 min |
| Jul 7, 7:24 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, McCone, Prairie, Richland, Roosevelt, Sheridan and 1 more | 66 min |
| Jul 7, 7:44 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 46 min |
| Jul 7, 7:58 PM MDT | Severe Thunderstorm Warning | GGW | Sheridan | 32 min |
| Jul 7, 8:24 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, Prairie, Richland, Wibaux | 25 min |
| Jul 9, 11:03 PM MDT | Severe Thunderstorm Warning | BYZ | Yellowstone | 42 min |
| Jul 10, 1:41 PM MDT | Severe Thunderstorm Warning | BYZ | Carter, Powder River | 64 min |
| Jul 10, 2:45 PM MDT | Severe Thunderstorm Warning | GGW | Richland, Roosevelt | 60 min |
| Jul 10, 4:27 PM MDT | Severe Thunderstorm Warning | GGW | Wibaux | 27 min |
| Jul 19, 7:36 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 46 min |
| Jul 23, 3:31 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, Prairie, Wibaux | 59 min |
| Jul 23, 3:47 PM MDT | Severe Thunderstorm Warning | BYZ | Fallon | 58 min |
| Jul 23, 4:04 PM MDT | Severe Thunderstorm Warning | TFX | Cascade | 26 min |
| Jul 23, 5:10 PM MDT | Severe Thunderstorm Warning | BYZ | Carbon, Golden Valley, Stillwater, Sweet Grass, Wheatland | 35 min |
| Jul 23, 5:18 PM MDT | Severe Thunderstorm Warning | TFX | Fergus, Judith Basin | 42 min |
| Jul 23, 5:35 PM MDT | Severe Thunderstorm Warning | GGW | Dawson, Richland, Wibaux | 55 min |
| Jul 23, 5:46 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Roosevelt, Valley | 44 min |
| Jul 23, 7:08 PM MDT | Severe Thunderstorm Warning | GGW | Sheridan | 35 min |
| Jul 23, 7:39 PM MDT | Severe Thunderstorm Warning | GGW | Sheridan | 34 min |
| Jul 23, 8:40 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Roosevelt | 15 min |
| Jul 25, 1:18 AM MDT | Severe Thunderstorm Warning | GGW | Phillips, Valley | 57 min |
| Jul 30, 7:43 PM MDT | Severe Thunderstorm Warning | BYZ | Custer | 32 min |
| Jul 31, 4:52 AM MDT | Severe Thunderstorm Warning | GGW | Phillips | 23 min |
| Jul 31, 2:22 PM MDT | Severe Thunderstorm Warning | TFX | Blaine, Chouteau, Hill | 23 min |
| Jul 31, 6:11 PM MDT | Severe Thunderstorm Warning | TFX | Hill | 34 min |
| Jul 31, 6:26 PM MDT | Severe Thunderstorm Warning | TFX | Liberty | 34 min |
| Jul 31, 6:59 PM MDT | Severe Thunderstorm Warning | TFX | Liberty | 31 min |
| Jul 31, 7:27 PM MDT | Severe Thunderstorm Warning | TFX | Liberty | 48 min |
| Aug 3, 12:19 PM MDT | Severe Thunderstorm Warning | TFX | Judith Basin | 41 min |
| Aug 3, 5:49 PM MDT | Severe Thunderstorm Warning | TFX | Gallatin, Madison | 26 min |
| Aug 3, 6:02 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 28 min |
| Aug 3, 6:54 PM MDT | Severe Thunderstorm Warning | BYZ | Park | 36 min |
| Aug 3, 9:19 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn, Yellowstone | 41 min |
| Aug 6, 3:30 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 19 min |
| Aug 6, 4:57 PM MDT | Severe Thunderstorm Warning | BYZ | Powder River | 49 min |
| Aug 6, 5:09 PM MDT | Severe Thunderstorm Warning | BYZ | Big Horn, Yellowstone | 51 min |
| Aug 6, 6:14 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 76 min |
| Aug 6, 7:28 PM MDT | Severe Thunderstorm Warning | TFX | Cascade | 32 min |
| Aug 6, 8:07 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, McCone, Valley | 38 min |
| Aug 11, 8:19 PM MDT | Severe Thunderstorm Warning | BYZ | Carter | 21 min |
| Aug 12, 4:17 PM MDT | Severe Thunderstorm Warning | GGW | Sheridan | 13 min |
| Aug 12, 5:33 PM MDT | Severe Thunderstorm Warning | GGW | Roosevelt, Sheridan | 42 min |
| Aug 12, 6:13 PM MDT | Severe Thunderstorm Warning | GGW | Richland, Roosevelt | 48 min |
| Aug 19, 6:16 PM MDT | Severe Thunderstorm Warning | TFX | Madison | 29 min |
| Aug 20, 2:22 PM MDT | Severe Thunderstorm Warning | TFX | Lewis and Clark, Teton | 38 min |
| Aug 20, 2:55 PM MDT | Severe Thunderstorm Warning | TFX | Cascade, Lewis and Clark, Pondera, Teton, Toole | 35 min |
| Aug 20, 3:28 PM MDT | Severe Thunderstorm Warning | TFX | Cascade, Chouteau, Liberty, Pondera, Teton, Toole | 32 min |
| Aug 20, 4:17 PM MDT | Severe Thunderstorm Warning | TFX | Cascade | 28 min |
| Aug 20, 4:54 PM MDT | Severe Thunderstorm Warning | TFX | Judith Basin | 21 min |
| Aug 20, 4:58 PM MDT | Severe Thunderstorm Warning | TFX | Broadwater, Lewis and Clark, Meagher | 32 min |
| Aug 20, 5:14 PM MDT | Severe Thunderstorm Warning | TFX | Judith Basin | 31 min |
| Aug 20, 5:35 PM MDT | Severe Thunderstorm Warning | TFX | Meagher | 25 min |
| Aug 20, 5:37 PM MDT | Severe Thunderstorm Warning | TFX | Fergus, Judith Basin | 38 min |
| Aug 20, 7:42 PM MDT | Severe Thunderstorm Warning | GGW | Phillips | 48 min |
| Aug 20, 8:04 PM MDT | Severe Thunderstorm Warning | BYZ | Golden Valley | 26 min |
| Aug 20, 8:49 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, McCone, Phillips, Valley | 56 min |
| Aug 20, 9:12 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, McCone, Prairie | 63 min |
| Aug 20, 9:43 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Dawson, Garfield, McCone, Prairie, Richland and 2 more | 62 min |
| Aug 20, 10:43 PM MDT | Severe Thunderstorm Warning | BYZ | Custer | 47 min |
| Aug 20, 10:43 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Dawson, McCone, Prairie, Richland, Roosevelt and 3 more | 62 min |
| Aug 25, 10:00 PM MDT | Severe Thunderstorm Warning | GGW | Garfield, McCone, Prairie | 60 min |
| Aug 26, 5:51 PM MDT | Severe Thunderstorm Warning | TFX | Madison | 24 min |
| Aug 26, 5:53 PM MDT | Severe Thunderstorm Warning | MSO | Ravalli | 22 min |
| Aug 27, 4:03 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Roosevelt, Valley | 28 min |
| Oct 30, 7:08 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Garfield, McCone, Roosevelt, Sheridan, Valley | 52 min |
| Oct 30, 7:43 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, Garfield, McCone, Roosevelt, Sheridan, Valley | 38 min |
| Oct 30, 7:56 PM MDT | Severe Thunderstorm Warning | GGW | Daniels, McCone, Richland, Roosevelt, Sheridan | 56 min |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- McCone County30
- Valley County28
- Garfield County26
- Roosevelt County25
- Carter County24
- Custer County19
- Daniels County18
- Dawson County16
- Phillips County16
- Powder River County16
- Fergus County15
- Prairie County15
- Sheridan County15
- Cascade County14
- Richland County14
- Wibaux County13
- Chouteau County12
- Judith Basin County11
- Rosebud County11
- Teton County9
- Blaine County9
- Hill County8
- Liberty County8
- Big Horn County8
- Fallon County7
- Lewis and Clark County6
- Golden Valley County6
- Petroleum County6
- Gallatin County6
- Yellowstone County6
- Musselshell County5
- Meagher County5
- Madison County5
- Wheatland County4
- Pondera County4
- Flathead County4
- Broadwater County3
- Treasure County3
- Lake County2
- Lincoln County2
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20192021
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.