Alert archive / Montana / Powell County
Weather alerts in Powell County, Montana, 2009
109 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Powell County and its neighbors
Each county as a circle sized by its count in 2009. Tap one for its archive.
- Alerts
- 109
- Warnings
- 27
- Watches
- 15
- Advisories
- 47
- Busiest month
- July21 alerts
- Busiest day
- July 6, 20099 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Powell County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 11 | 4 | 64% | 0 | ||
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Missoula, MT: severe thunderstorm warnings | 30 | 13 | 57% | 35 | 80% | 22 min |
| NWS Missoula, MT: flash flood warnings | 3 | 1 | 67% | 8 | 13% | 48 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 1, 12:57 PM MST | Winter Weather Advisory | MSO | 28 hr |
| Jan 2, 8:57 AM MST | Wind Advisory | MSO | 5 hr |
| Jan 3, 3:03 PM MST | Winter Storm Watch | MSO | 13 hr |
| Jan 4, 4:10 AM MST | Winter Storm Warning | MSO | 41 hr |
| Jan 5, 2:56 PM MST | Winter Storm Watch | MSO | 13 hr |
| Jan 6, 4:15 AM MST | Winter Storm Warning | MSO | 30 hr |
| Jan 16, 7:27 AM MST | Dense Fog Advisory | MSO | 49 hr |
| Jan 17, 10:33 AM MST | Dense Fog Advisory | MSO | 26 hr |
| Jan 23, 8:11 AM MST | Wind Chill Advisory | MSO | 4 hr |
| Jan 24, 3:25 AM MST | Wind Chill Advisory | MSO | 35 hr |
| Jan 24, 3:25 AM MST | Winter Weather Advisory | MSO | 32 hr |
| Jan 26, 2:41 PM MST | Winter Weather Advisory | MSO | 48 hr |
| Jan 30, 4:43 AM MST | Winter Storm Watch | MSO | 10 hr |
| Jan 30, 2:43 PM MST | Winter Weather Advisory | MSO | 21 hr |
| Feb 18, 8:13 AM MST | Winter Weather Advisory | MSO | 6 hr |
| Feb 23, 2:36 PM MST | Winter Weather Advisory | MSO | 27 hr |
| Feb 24, 3:06 PM MST | Winter Storm Watch | MSO | 13 hr |
| Feb 25, 4:32 AM MST | Winter Storm Warning | MSO | 42 hr |
| Feb 25, 4:32 AM MST | Winter Weather Advisory | MSO | 10 hr |
| Mar 3, 6:19 AM MST | Dense Fog Advisory | MSO | 3 hr |
| Mar 3, 2:08 PM MST | Winter Storm Watch | MSO | 43 hr |
| Mar 4, 2:29 PM MST | Winter Weather Advisory | MSO | 44 hr |
| Mar 7, 4:24 AM MST | Winter Weather Advisory | MSO | 37 hr |
| Mar 8, 2:23 PM MDT | Wind Chill Advisory | MSO | 23 hr |
| Mar 9, 4:45 AM MDT | Winter Weather Advisory | MSO | 32 hr |
| Mar 9, 11:08 PM MDT | Wind Chill Advisory | MSO | 5 hr |
| Mar 13, 2:44 PM MDT | Winter Weather Advisory | MSO | 3 days |
| Mar 14, 9:07 PM MDT | Winter Storm Warning | MSO | 47 hr |
| Mar 16, 5:44 PM MDT | Winter Weather Advisory | MSO | 10 hr |
| Mar 17, 7:47 AM MDT | Winter Weather Advisory | MSO | 4 hr |
| Mar 22, 1:46 PM MDT | Winter Weather Advisory | MSO | 14 hr |
| Mar 23, 2:10 PM MDT | Winter Storm Watch | MSO | 38 hr |
| Mar 24, 2:12 PM MDT | Winter Storm Warning | MSO | 33 hr |
| Mar 24, 2:12 PM MDT | Winter Weather Advisory | MSO | 33 hr |
| Mar 28, 4:10 AM MDT | Winter Storm Warning | MSO | 44 hr |
| Mar 28, 4:10 AM MDT | Winter Weather Advisory | MSO | 44 hr |
| Mar 30, 2:51 PM MDT | Winter Weather Advisory | MSO | 39 hr |
| Mar 31, 1:10 PM MDT | Winter Storm Warning | MSO | 17 hr |
| Apr 1, 9:58 PM MDT | Winter Weather Advisory | MSO | 32 hr |
| Apr 14, 9:02 AM MDT | Winter Weather Advisory | MSO | 30 hr |
| Apr 23, 4:31 PM MDT | Winter Weather Advisory | MSO | 5 hr |
| Apr 27, 3:54 AM MDT | Winter Storm Warning | MSO | 56 hr |
| Apr 27, 2:35 PM MDT | Winter Weather Advisory | MSO | 39 hr |
| May 11, 2:41 PM MDT | Winter Weather Advisory | MSO | 30 hr |
| May 19, 4:10 AM MDT | Wind Advisory | MSO | 16 hr |
| Jun 6, 8:46 AM MDT | Special Weather Statement | MSO | 44 min |
| Jun 25, 4:16 PM MDT | Special Weather Statement | MSO | 44 min |
| Jul 6, 1:05 PM MDT | Mesoscale Discussion | SPC | 55 min |
| Jul 6, 1:24 PM MDT | Special Weather Statement | MSO | 36 min |
| Jul 6, 1:33 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 6, 1:37 PM MDT | Severe Thunderstorm Warning | MSO | 23 min |
| Jul 6, 1:45 PM MDT | Severe Thunderstorm Warning | MSO | 45 min |
| Jul 6, 2:07 PM MDT | Severe Thunderstorm Warning | MSO | 38 min |
| Jul 6, 2:29 PM MDT | Severe Thunderstorm Warning | MSO | 46 min |
| Jul 6, 3:03 PM MDT | Severe Thunderstorm Warning | MSO | 27 min |
| Jul 6, 4:02 PM MDT | Mesoscale Discussion | SPC | 58 min |
| Jul 8, 3:32 PM MDT | Special Weather Statement | MSO | 58 min |
| Jul 12, 10:35 PM MDT | Special Weather Statement | MSO | 40 min |
| Jul 23, 11:35 PM MDT | Special Weather Statement | MSO | 25 min |
| Jul 24, 1:17 PM MDT | Mesoscale Discussion | SPC | 88 min |
| Jul 24, 2:49 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 24, 5:37 PM MDT | Severe Thunderstorm Warning | MSO | 38 min |
| Jul 25, 12:40 PM MDT | Mesoscale Discussion | SPC | 95 min |
| Jul 25, 4:50 PM MDT | Special Weather Statement | MSO | 25 min |
| Jul 26, 3:04 PM MDT | Special Weather Statement | MSO | 26 min |
| Jul 26, 3:29 PM MDT | Special Weather Statement | MSO | 61 min |
| Jul 26, 5:56 PM MDT | Severe Thunderstorm Warning | MSO | 49 min |
| Jul 28, 2:35 PM MDT | Mesoscale Discussion | SPC | 55 min |
| Aug 6, 12:04 PM MDT | Mesoscale Discussion | SPC | 56 min |
| Aug 6, 12:34 PM MDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 7, 12:33 PM MDT | Special Weather Statement | MSO | 42 min |
| Aug 7, 1:52 PM MDT | Areal Flood Advisory | MSO | 101 min |
| Aug 13, 2:54 PM MDT | Special Weather Statement | MSO | 51 min |
| Aug 21, 5:52 PM MDT | Special Weather Statement | MSO | 38 min |
| Aug 21, 6:31 PM MDT | Severe Thunderstorm Warning | MSO | 22 min |
| Aug 21, 6:48 PM MDT | Special Weather Statement | MSO | 42 min |
| Aug 21, 7:00 PM MDT | Mesoscale Discussion | SPC | 90 min |
| Aug 21, 7:04 PM MDT | Severe Thunderstorm Warning | MSO | 41 min |
| Aug 21, 7:38 PM MDT | Severe Thunderstorm Warning | MSO | 37 min |
| Aug 21, 8:10 PM MDT | Severe Thunderstorm Warning | MSO | 50 min |
| Sep 18, 3:17 PM MDT | Fire Weather Watch | TFX | 23 hr |
| Sep 20, 2:39 PM MDT | Frost Advisory | MSO | 18 hr |
| Sep 24, 2:43 PM MDT | Fire Weather Watch | TFX | 24 hr |
| Sep 24, 2:45 PM MDT | Fire Weather Watch | MSO | 23 hr |
| Sep 25, 1:47 PM MDT | Red Flag Warning | MSO | 33 hr |
| Sep 25, 2:45 PM MDT | Red Flag Warning | TFX | 31 hr |
| Sep 28, 2:43 PM MDT | Fire Weather Watch | MSO | 17 hr |
| Sep 29, 7:37 AM MDT | Red Flag Warning | MSO | 12 hr |
| Sep 29, 2:37 PM MDT | Winter Weather Advisory | MSO | 13 hr |
| Oct 3, 2:05 PM MDT | Wind Advisory | MSO | 20 hr |
| Oct 3, 2:06 PM MDT | Red Flag Warning | MSO | 14 hr |
| Oct 4, 3:36 AM MDT | Winter Storm Warning | MSO | 32 hr |
| Oct 6, 2:50 PM MDT | Winter Weather Advisory | MSO | 29 hr |
| Oct 7, 1:56 PM MDT | Winter Weather Advisory | MSO | 46 hr |
| Oct 10, 4:32 AM MDT | Wind Chill Advisory | MSO | 25 hr |
| Oct 25, 3:54 AM MDT | Winter Storm Watch | MSO | 24 hr |
| Oct 26, 3:59 AM MDT | Winter Storm Warning | MSO | 32 hr |
| Oct 31, 3:35 AM MDT | Wind Advisory | MSO | 17 hr |
| Nov 11, 6:46 AM MST | Winter Weather Advisory | MSO | 6 hr |
| Dec 4, 2:05 PM MST | Wind Chill Warning | MSO | 69 hr |
| Dec 4, 2:05 PM MST | Winter Weather Advisory | MSO | 27 hr |
| Dec 11, 4:27 AM MST | Winter Storm Watch | MSO | 24 hr |
| Dec 11, 1:30 PM MST | Winter Storm Warning | MSO | 3 days |
| Dec 14, 2:53 PM MST | Winter Weather Advisory | MSO | 24 hr |
| Dec 15, 4:56 PM MST | Winter Weather Advisory | MSO | 18 hr |
| Dec 16, 6:34 PM MST | Freezing Rain Advisory | MSO | 16 hr |
| Dec 20, 5:19 AM MST | Freezing Rain Advisory | MSO | 4 hr |
| Dec 22, 5:08 AM MST | Winter Weather Advisory | MSO | 30 hr |
| Dec 30, 2:47 PM MST | Winter Weather Advisory | MSO | 20 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 | 11 |
| Severe Thunderstorm Watch | 3 |
| Mesoscale Discussion | 7 |
| Special Weather Statement | 13 |
| Flooding | |
| Areal Flood Advisory | 1 |
| Winter | |
| Winter Storm Warning | 11 |
| Winter Storm Watch | 8 |
| Freezing Rain Advisory | 2 |
| Winter Weather Advisory | 31 |
| Cold | |
| Wind Chill Warning | 1 |
| Frost Advisory | 1 |
| Wind Chill Advisory | 5 |
| Wind and dust | |
| Wind Advisory | 4 |
| Fire | |
| Red Flag Warning | 4 |
| Fire Weather Watch | 4 |
| 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 archive20082010
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.