Alert archive / Montana / Yellowstone County
Weather alerts in Yellowstone County, Montana, 2019
143 weather alerts in 2019, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Yellowstone County and its neighbors
Each county as a circle sized by its count in 2019. Tap one for its archive.
- Alerts
- 143
- Warnings
- 23
- Watches
- 9
- Advisories
- 9
- Busiest month
- June39 alerts
- Busiest day
- May 27, 201910 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 1 tornado reports fell inside a warning.
Yellowstone County, 2019
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 1 | 0% | |||
| Severe thunderstorm warnings | 18 | 11 | 39% | 74 | 78% | 35 min |
| Flash flood warnings | 2 | 0 | 100% | 0 |
Each office's whole area, 2019
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Billings, MT: tornado warnings | 3 | 0 | 100% | 4 | 0% | |
| NWS Billings, MT: severe thunderstorm warnings | 185 | 83 | 55% | 233 | 73% | 29 min |
| NWS Billings, MT: flash flood warnings | 12 | 4 | 67% | 12 | 67% | 171 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 7, 9:46 AM MST | Special Weather Statement | BYZ | 44 min |
| Jan 18, 5:05 AM MST | Special Weather Statement | BYZ | 4 hr |
| Feb 24, 4:44 PM MST | Mesoscale Discussion | SPC | 6 hr |
| Mar 1, 5:17 PM MST | Special Weather Statement | BYZ | 28 min |
| Mar 1, 5:26 PM MST | Special Weather Statement | BYZ | 64 min |
| Mar 1, 6:41 PM MST | Special Weather Statement | BYZ | 79 min |
| Mar 31, 10:30 PM MDT | Special Weather Statement | BYZ | 45 min |
| Apr 1, 1:47 PM MDT | Special Weather Statement | BYZ | 43 min |
| Apr 1, 2:34 PM MDT | Special Weather Statement | BYZ | 41 min |
| Apr 24, 1:26 PM MDT | Special Weather Statement | BYZ | 49 min |
| May 5, 7:58 AM MDT | Special Weather Statement | BYZ | 4 hr |
| May 20, 2:43 PM MDT | Flood Watch | BYZ | 48 hr |
| May 26, 7:04 PM MDT | Severe Thunderstorm Warning | BYZ | 56 min |
| May 26, 7:39 PM MDT | Special Weather Statement | BYZ | 51 min |
| May 26, 7:41 PM MDT | Flash Flood Warning | BYZ | 4 hr |
| May 26, 7:52 PM MDT | Severe Thunderstorm Warning | BYZ | 53 min |
| May 26, 8:37 PM MDT | Special Weather Statement | BYZ | 53 min |
| May 26, 8:42 PM MDT | Flash Flood Warning | BYZ | 6 hr |
| May 26, 9:02 PM MDT | Special Weather Statement | BYZ | 43 min |
| May 26, 9:15 PM MDT | Severe Thunderstorm Warning | BYZ | 30 min |
| May 26, 9:33 PM MDT | Special Weather Statement | BYZ | 57 min |
| May 26, 9:47 PM MDT | Special Weather Statement | BYZ | 43 min |
| May 27, 7:23 PM MDT | Areal Flood Warning | BYZ | 15 hr |
| May 30, 1:37 PM MDT | Flash Flood Watch | BYZ | 32 hr |
| Jun 8, 6:33 PM MDT | Special Weather Statement | BYZ | 57 min |
| Jun 8, 6:35 PM MDT | Special Weather Statement | BYZ | 55 min |
| Jun 8, 7:44 PM MDT | Special Weather Statement | BYZ | 61 min |
| Jun 13, 4:47 PM MDT | Special Weather Statement | BYZ | 43 min |
| Jun 13, 5:29 PM MDT | Special Weather Statement | BYZ | 46 min |
| Jun 13, 6:18 PM MDT | Special Weather Statement | BYZ | 42 min |
| Jun 14, 12:21 PM MDT | Mesoscale Discussion | SPC | 114 min |
| Jun 14, 3:12 PM MDT | Special Weather Statement | BYZ | 63 min |
| Jun 14, 3:47 PM MDT | Severe Thunderstorm Warning | BYZ | 43 min |
| Jun 14, 4:33 PM MDT | Special Weather Statement | BYZ | 42 min |
| Jun 14, 6:41 PM MDT | Special Weather Statement | BYZ | 49 min |
| Jun 14, 7:28 PM MDT | Special Weather Statement | BYZ | 47 min |
| Jun 15, 10:51 PM MDT | Special Weather Statement | BYZ | 39 min |
| Jun 18, 3:27 PM MDT | Special Weather Statement | BYZ | 48 min |
| Jun 20, 2:48 PM MDT | Special Weather Statement | BYZ | 42 min |
| Jun 20, 3:27 PM MDT | Mesoscale Discussion | SPC | 63 min |
| Jun 20, 3:29 PM MDT | Special Weather Statement | BYZ | 46 min |
| Jun 20, 3:44 PM MDT | Special Weather Statement | BYZ | 31 min |
| Jun 20, 4:13 PM MDT | Special Weather Statement | BYZ | 47 min |
| Jun 20, 5:30 PM MDT | Special Weather Statement | BYZ | 45 min |
| Jun 20, 6:12 PM MDT | Special Weather Statement | BYZ | 48 min |
| Jun 20, 6:49 PM MDT | Special Weather Statement | BYZ | 56 min |
| Jun 20, 7:52 PM MDT | Special Weather Statement | BYZ | 38 min |
| Jun 20, 8:40 PM MDT | Special Weather Statement | BYZ | 50 min |
| Jun 24, 7:18 PM MDT | Special Weather Statement | BYZ | 42 min |
| Jun 24, 8:05 PM MDT | Special Weather Statement | BYZ | 40 min |
| Jun 25, 2:36 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 25, 3:12 PM MDT | Special Weather Statement | BYZ | 48 min |
| Jun 25, 3:29 PM MDT | Severe Thunderstorm Warning | BYZ | 40 min |
| Jun 26, 1:48 PM MDT | Mesoscale Discussion | SPC | 117 min |
| Jun 26, 2:16 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 26, 6:03 PM MDT | Mesoscale Discussion | SPC | 57 min |
| Jun 27, 5:28 PM MDT | Mesoscale Discussion | SPC | 62 min |
| Jun 28, 2:36 PM MDT | Mesoscale Discussion | SPC | 114 min |
| Jun 30, 3:38 PM MDT | Special Weather Statement | BYZ | 67 min |
| Jun 30, 4:18 PM MDT | Special Weather Statement | BYZ | 42 min |
| Jun 30, 4:34 PM MDT | Mesoscale Discussion | SPC | 86 min |
| Jun 30, 5:10 PM MDT | Special Weather Statement | BYZ | 50 min |
| Jun 30, 5:39 PM MDT | Severe Thunderstorm Warning | BYZ | 11 min |
| Jul 1, 4:40 PM MDT | Mesoscale Discussion | SPC | 95 min |
| Jul 1, 5:26 PM MDT | Special Weather Statement | BYZ | 49 min |
| Jul 1, 6:15 PM MDT | Severe Thunderstorm Warning | BYZ | 45 min |
| Jul 1, 6:19 PM MDT | Special Weather Statement | BYZ | 26 min |
| Jul 3, 4:40 PM MDT | Special Weather Statement | BYZ | 35 min |
| Jul 7, 1:44 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 7, 2:58 PM MDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jul 7, 6:27 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 7, 10:28 PM MDT | Special Weather Statement | BYZ | 47 min |
| Jul 8, 7:15 AM MDT | Special Weather Statement | BYZ | 45 min |
| Jul 8, 12:53 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 8, 1:25 PM MDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jul 8, 5:20 PM MDT | Special Weather Statement | BYZ | 25 min |
| Jul 9, 11:32 AM MDT | Special Weather Statement | BYZ | 43 min |
| Jul 9, 12:50 PM MDT | Special Weather Statement | BYZ | 40 min |
| Jul 11, 1:44 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 11, 5:21 PM MDT | Severe Thunderstorm Warning | BYZ | 39 min |
| Jul 11, 6:11 PM MDT | Special Weather Statement | BYZ | 49 min |
| Jul 11, 6:19 PM MDT | Severe Thunderstorm Warning | BYZ | 26 min |
| Jul 12, 7:13 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 12, 9:36 PM MDT | Special Weather Statement | BYZ | 54 min |
| Jul 13, 4:10 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 13, 4:18 PM MDT | Severe Thunderstorm Warning | BYZ | 57 min |
| Jul 13, 5:16 PM MDT | Special Weather Statement | BYZ | 44 min |
| Jul 14, 2:48 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 14, 6:14 PM MDT | Severe Thunderstorm Warning | BYZ | 61 min |
| Jul 14, 6:15 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 14, 7:11 PM MDT | Severe Thunderstorm Warning | BYZ | 36 min |
| Jul 14, 7:54 PM MDT | Special Weather Statement | BYZ | 51 min |
| Jul 14, 8:06 PM MDT | Areal Flood Advisory | BYZ | 91 min |
| Jul 15, 1:36 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 16, 12:56 PM MDT | Mesoscale Discussion | SPC | 94 min |
| Jul 16, 1:28 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 22, 9:26 PM MDT | Special Weather Statement | BYZ | 64 min |
| Jul 23, 4:13 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 23, 9:15 PM MDT | Special Weather Statement | BYZ | 45 min |
| Jul 24, 6:33 PM MDT | Special Weather Statement | BYZ | 42 min |
| Jul 24, 6:49 PM MDT | Severe Thunderstorm Warning | BYZ | 41 min |
| Jul 30, 6:40 PM MDT | Special Weather Statement | BYZ | 50 min |
| Aug 1, 5:15 PM MDT | Special Weather Statement | BYZ | 45 min |
| Aug 1, 6:03 PM MDT | Special Weather Statement | BYZ | 57 min |
| Aug 10, 12:44 PM MDT | Mesoscale Discussion | SPC | 91 min |
| Aug 10, 3:04 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 10, 4:23 PM MDT | Special Weather Statement | BYZ | 52 min |
| Aug 10, 4:53 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 10, 5:23 PM MDT | Special Weather Statement | BYZ | 52 min |
| Aug 10, 8:34 PM MDT | Mesoscale Discussion | SPC | 86 min |
| Aug 11, 12:15 PM MDT | Mesoscale Discussion | SPC | 90 min |
| Aug 11, 1:59 PM MDT | Tornado Watch | SPC | 10 hr |
| Aug 11, 5:54 PM MDT | Mesoscale Discussion | SPC | 66 min |
| Aug 11, 6:27 PM MDT | Severe Thunderstorm Warning | BYZ | 63 min |
| Aug 11, 7:25 PM MDT | Severe Thunderstorm Warning | BYZ | 50 min |
| Aug 11, 7:26 PM MDT | Areal Flood Advisory | BYZ | 2 hr |
| Aug 11, 8:02 PM MDT | Severe Thunderstorm Warning | BYZ | 58 min |
| Aug 18, 7:38 AM MDT | Special Weather Statement | BYZ | 82 min |
| Aug 22, 6:59 PM MDT | Severe Thunderstorm Warning | BYZ | 46 min |
| Aug 22, 7:25 PM MDT | Severe Thunderstorm Warning | BYZ | 53 min |
| Aug 24, 10:52 PM MDT | Special Weather Statement | BYZ | 23 min |
| Sep 3, 9:30 AM MDT | Red Flag Warning | BYZ | 36 hr |
| Sep 16, 6:11 PM MDT | Special Weather Statement | BYZ | 49 min |
| Oct 9, 4:52 AM MDT | Mesoscale Discussion | SPC | 4 hr |
| Oct 22, 2:50 PM MDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 22, 5:47 PM MDT | Special Weather Statement | BYZ | 43 min |
| Oct 22, 7:13 PM MDT | Special Weather Statement | BYZ | 62 min |
| Oct 26, 8:12 AM MDT | Special Weather Statement | BYZ | 108 min |
| Oct 27, 2:43 PM MDT | Winter Weather Advisory | BYZ | 39 hr |
| Oct 28, 12:51 PM MDT | Special Weather Statement | BYZ | 99 min |
| Nov 4, 7:51 PM MST | Special Weather Statement | BYZ | 4 hr |
| Nov 5, 3:10 AM MST | Winter Weather Advisory | BYZ | 32 hr |
| Nov 8, 2:39 PM MST | Winter Weather Advisory | BYZ | 54 hr |
| Nov 10, 2:59 AM MST | Special Weather Statement | BYZ | 3 hr |
| Nov 10, 5:07 PM MST | Special Weather Statement | BYZ | 83 min |
| Nov 14, 1:02 AM MST | Dense Fog Advisory | BYZ | 9 hr |
| Nov 26, 9:45 AM MST | Winter Storm Watch | BYZ | 25 hr |
| Nov 27, 10:22 AM MST | Winter Storm Warning | BYZ | 3 days |
| Dec 7, 3:14 AM MST | Winter Weather Advisory | BYZ | 41 hr |
| Dec 13, 8:16 AM MST | Winter Weather Advisory | BYZ | 11 hr |
| Dec 13, 5:08 PM MST | Special Weather Statement | BYZ | 3 hr |
| Dec 13, 7:26 PM MST | Dense Fog Advisory | BYZ | 15 hr |
| Dec 14, 10:51 AM MST | Special Weather Statement | BYZ | 114 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 | 18 |
| Severe Thunderstorm Watch | 5 |
| Tornado Watch | 1 |
| Mesoscale Discussion | 28 |
| Special Weather Statement | 74 |
| Flooding | |
| Areal Flood Warning | 1 |
| Flash Flood Warning | 2 |
| Flash Flood Watch | 1 |
| Flood Watch | 1 |
| Areal Flood Advisory | 2 |
| Winter | |
| Winter Storm Warning | 1 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 5 |
| Fire | |
| Red Flag Warning | 1 |
| Fog and smoke | |
| Dense Fog Advisory | 2 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20182020
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.