Weather alerts in Valley County, Montana, 2009

178 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Valley County and its neighbors

Each county as a circle sized by its count in 2009. Tap one for its archive.

Alerts: 178
Warnings: 46
Watches: 17
Advisories: 105
Busiest month: July40 alerts
Busiest day: July 7, 20098 alerts

Over time

By month

Warning verification

How often warnings here had a storm report inside them, and how much warning the reports had.

1 of 5 tornado warnings covering Valley County in 2009 had a tornado report inside them; 2 of 3 tornado reports fell inside a warning, on average 6 minutes after it went out.

Valley County, 2009

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	5	1	80%	3	67%	6 min
Severe thunderstorm warnings	26	18	31%	32	66%	20 min
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 Glasgow, MT: tornado warnings	18	2	89%	7	43%	13 min
NWS Glasgow, MT: severe thunderstorm warnings	105	58	45%	157	68%	27 min
NWS Glasgow, MT: flash flood warnings	4	0	100%	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 1, 1:48 AM MST	Winter Weather Advisory	GGW	8 hr
Jan 1, 9:24 PM MST	Winter Weather Advisory	GGW	37 hr
Jan 3, 3:55 AM MST	Wind Chill Advisory	GGW	15 hr
Jan 6, 3:03 PM MST	Winter Weather Advisory	GGW	24 hr
Jan 7, 3:48 AM MST	Winter Storm Watch	GGW	24 hr
Jan 8, 3:18 AM MST	Winter Weather Advisory	GGW	7 hr
Jan 8, 3:18 AM MST	Freezing Rain Advisory	GGW	7 hr
Jan 8, 10:28 AM MST	Ice Storm Warning	GGW	11 hr
Jan 8, 3:04 PM MST	Winter Weather Advisory	GGW	20 hr
Jan 10, 2:45 PM MST	High Wind Watch	GGW	24 hr
Jan 11, 4:07 AM MST	Blizzard Warning	GGW	24 hr
Jan 11, 3:01 PM MST	High Wind Warning	GGW	19 hr
Jan 13, 2:50 PM MST	Wind Chill Advisory	GGW	13 hr
Jan 13, 2:50 PM MST	Winter Weather Advisory	GGW	8 hr
Jan 13, 5:41 PM MST	High Wind Warning	GGW	3 hr
Jan 14, 7:46 PM MST	Wind Chill Advisory	GGW	8 hr
Jan 16, 7:43 PM MST	Winter Weather Advisory	GGW	4 hr
Jan 22, 3:40 AM MST	Wind Chill Advisory	GGW	37 hr
Jan 22, 12:09 PM MST	Winter Weather Advisory	GGW	15 hr
Jan 26, 9:17 PM MST	Wind Chill Advisory	GGW	13 hr
Jan 31, 4:02 AM MST	High Wind Warning	GGW	8 hr
Feb 9, 7:32 AM MST	Dense Fog Advisory	GGW	5 hr
Feb 10, 8:14 AM MST	Winter Weather Advisory	GGW	10 hr
Feb 13, 2:23 PM MST	Wind Chill Advisory	GGW	13 hr
Feb 17, 3:27 AM MST	Dense Fog Advisory	GGW	8 hr
Feb 19, 2:58 PM MST	Winter Weather Advisory	GGW	13 hr
Feb 23, 2:57 PM MST	Winter Weather Advisory	GGW	22 hr
Feb 25, 3:22 AM MST	Winter Weather Advisory	GGW	56 hr
Feb 26, 2:58 PM MST	Wind Chill Advisory	GGW	20 hr
Mar 4, 7:42 AM MST	Dense Fog Advisory	GGW	5 hr
Mar 4, 9:20 PM MST	Dense Fog Advisory	GGW	10 hr
Mar 8, 2:34 PM MDT	Wind Chill Advisory	GGW	54 hr
Mar 21, 11:20 AM MDT	Areal Flood Advisory	GGW	24 hr
Mar 27, 3:10 PM MDT	Winter Storm Watch	GGW	24 hr
Mar 28, 3:16 PM MDT	Winter Weather Advisory	GGW	37 hr
Apr 22, 8:05 AM MDT	Red Flag Warning	GGW	12 hr
Apr 22, 9:03 AM MDT	Lake Wind Advisory	GGW	11 hr
Apr 23, 3:49 AM MDT	Lake Wind Advisory	GGW	13 hr
Apr 27, 2:36 PM MDT	Lake Wind Advisory	GGW	61 hr
Apr 27, 2:45 PM MDT	Winter Storm Watch	GGW	24 hr
Apr 28, 2:46 PM MDT	Winter Storm Warning	GGW	36 hr
Apr 29, 4:08 AM MDT	Winter Weather Advisory	GGW	23 hr
May 1, 1:23 PM MDT	Lake Wind Advisory	GGW	8 hr
May 4, 9:44 AM MDT	Lake Wind Advisory	GGW	9 hr
May 5, 3:49 AM MDT	Lake Wind Advisory	GGW	15 hr
May 6, 3:20 AM MDT	Lake Wind Advisory	GGW	18 hr
May 7, 3:24 AM MDT	Lake Wind Advisory	GGW	17 hr
May 7, 3:55 PM MDT	Severe Thunderstorm Warning	GGW	34 min
May 8, 1:36 PM MDT	Lake Wind Advisory	GGW	6 hr
May 12, 3:40 PM MDT	Lake Wind Advisory	GGW	28 hr
May 13, 9:11 AM MDT	Winter Weather Advisory	GGW	3 hr
May 14, 6:10 PM MDT	Severe Thunderstorm Warning	GGW	48 min
May 18, 9:23 AM MDT	Lake Wind Advisory	GGW	33 hr
May 19, 2:39 PM MDT	Lake Wind Advisory	GGW	29 hr
May 19, 8:53 PM MDT	Severe Thunderstorm Warning	GGW	67 min
May 19, 9:04 PM MDT	Severe Thunderstorm Warning	GGW	56 min
May 28, 9:30 AM MDT	Lake Wind Advisory	GGW	5 hr
Jun 1, 3:35 AM MDT	Lake Wind Advisory	GGW	11 hr
Jun 4, 6:16 PM MDT	Lake Wind Advisory	GGW	4 hr
Jun 5, 2:41 PM MDT	Lake Wind Advisory	GGW	30 hr
Jun 18, 3:32 AM MDT	Lake Wind Advisory	GGW	16 hr
Jun 22, 3:16 AM MDT	Lake Wind Advisory	GGW	16 hr
Jun 24, 3:21 PM MDT	Red Flag Warning	GGW	5 hr
Jun 25, 3:50 AM MDT	Red Flag Warning	GGW	17 hr
Jun 25, 6:07 PM MDT	Severe Thunderstorm Warning	GGW	23 min
Jun 25, 6:31 PM MDT	Severe Thunderstorm Warning	GGW	29 min
Jul 3, 3:44 AM MDT	Lake Wind Advisory	GGW	11 hr
Jul 3, 2:21 PM MDT	Mesoscale Discussion	SPC	114 min
Jul 3, 4:31 PM MDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 3, 5:01 PM MDT	Severe Thunderstorm Warning	GGW	59 min
Jul 3, 5:53 PM MDT	Severe Thunderstorm Warning	GGW	67 min
Jul 3, 6:37 PM MDT	Special Weather Statement	GGW	53 min
Jul 3, 6:56 PM MDT	Severe Thunderstorm Warning	GGW	64 min
Jul 3, 7:57 PM MDT	Severe Thunderstorm Warning	GGW	63 min
Jul 5, 5:29 AM MDT	Lake Wind Advisory	GGW	5 hr
Jul 5, 3:41 PM MDT	Severe Thunderstorm Warning	GGW	64 min
Jul 5, 3:48 PM MDT	Mesoscale Discussion	SPC	57 min
Jul 5, 3:55 PM MDT	Tornado Warning	GGW	35 min
Jul 5, 4:30 PM MDT	Tornado Warning	GGW	45 min
Jul 6, 2:59 AM MDT	Lake Wind Advisory	GGW	19 hr
Jul 6, 6:23 PM MDT	Mesoscale Discussion	SPC	67 min
Jul 6, 7:23 PM MDT	Severe Thunderstorm Watch	SPC	5 hr
Jul 6, 7:40 PM MDT	Severe Thunderstorm Warning	GGW	65 min
Jul 6, 8:43 PM MDT	Severe Thunderstorm Warning	GGW	62 min
Jul 6, 8:57 PM MDT	Tornado Warning	GGW	48 min
Jul 6, 9:36 PM MDT	Severe Thunderstorm Warning	GGW	54 min
Jul 6, 9:44 PM MDT	Severe Thunderstorm Warning	GGW	61 min
Jul 6, 10:11 PM MDT	Tornado Warning	GGW	34 min
Jul 8, 9:23 PM MDT	Lake Wind Advisory	GGW	23 hr
Jul 13, 1:02 PM MDT	Severe Thunderstorm Watch	SPC	9 hr
Jul 13, 5:02 PM MDT	Severe Thunderstorm Warning	GGW	58 min
Jul 13, 5:05 PM MDT	Mesoscale Discussion	SPC	55 min
Jul 13, 5:09 PM MDT	Severe Thunderstorm Warning	GGW	66 min
Jul 13, 5:47 PM MDT	Severe Thunderstorm Warning	GGW	58 min
Jul 13, 6:32 PM MDT	Severe Thunderstorm Warning	GGW	58 min
Jul 13, 7:06 PM MDT	Severe Thunderstorm Warning	GGW	54 min
Jul 13, 7:31 PM MDT	Tornado Warning	GGW	29 min
Jul 14, 3:48 AM MDT	Lake Wind Advisory	GGW	16 hr
Jul 17, 2:54 PM MDT	Fire Weather Watch	GGW	24 hr
Jul 18, 2:58 PM MDT	Red Flag Warning	GGW	30 hr
Jul 19, 3:41 AM MDT	Lake Wind Advisory	GGW	17 hr
Jul 20, 2:52 AM MDT	Lake Wind Advisory	GGW	16 hr
Jul 22, 2:52 PM MDT	Fire Weather Watch	GGW	13 hr
Jul 23, 3:57 AM MDT	Red Flag Warning	GGW	17 hr
Jul 23, 4:00 AM MDT	Lake Wind Advisory	GGW	17 hr
Jul 31, 3:31 AM MDT	Lake Wind Advisory	GGW	17 hr
Aug 4, 3:27 AM MDT	Lake Wind Advisory	GGW	12 hr
Aug 6, 7:39 PM MDT	Severe Thunderstorm Watch	SPC	5 hr
Aug 6, 9:55 PM MDT	Mesoscale Discussion	SPC	65 min
Aug 12, 7:54 PM MDT	Special Weather Statement	GGW	66 min
Aug 13, 7:45 PM MDT	Lake Wind Advisory	GGW	7 hr
Aug 14, 5:10 PM MDT	Mesoscale Discussion	SPC	65 min
Aug 14, 8:00 PM MDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 15, 8:32 AM MDT	Lake Wind Advisory	GGW	8 hr
Aug 16, 3:13 AM MDT	Lake Wind Advisory	GGW	18 hr
Aug 18, 2:57 PM MDT	Lake Wind Advisory	GGW	30 hr
Aug 23, 7:55 PM MDT	Tornado Watch	SPC	5 hr
Aug 23, 8:30 PM MDT	Severe Thunderstorm Warning	GGW	60 min
Aug 23, 9:28 PM MDT	Severe Thunderstorm Warning	GGW	30 min
Aug 30, 2:39 PM MDT	Lake Wind Advisory	GGW	5 hr
Sep 5, 7:29 PM MDT	Lake Wind Advisory	GGW	8 hr
Sep 6, 8:50 PM MDT	Lake Wind Advisory	GGW	10 hr
Sep 6, 9:01 PM MDT	Severe Thunderstorm Warning	GGW	59 min
Sep 8, 3:36 AM MDT	Lake Wind Advisory	GGW	15 hr
Sep 8, 2:44 PM MDT	Red Flag Warning	GGW	28 hr
Sep 9, 2:33 PM MDT	Lake Wind Advisory	GGW	30 hr
Sep 12, 2:51 PM MDT	Lake Wind Advisory	GGW	30 hr
Sep 13, 1:44 PM MDT	Mesoscale Discussion	SPC	61 min
Sep 13, 2:35 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Sep 13, 6:29 PM MDT	Mesoscale Discussion	SPC	91 min
Sep 13, 7:43 PM MDT	Severe Thunderstorm Warning	GGW	62 min
Sep 13, 10:11 PM MDT	Severe Thunderstorm Warning	GGW	64 min
Sep 14, 1:32 AM MDT	Severe Thunderstorm Warning	GGW	58 min
Sep 18, 4:05 AM MDT	Fire Weather Watch	GGW	23 hr
Sep 19, 3:31 AM MDT	Red Flag Warning	GGW	20 hr
Sep 19, 2:45 PM MDT	Lake Wind Advisory	GGW	33 hr
Sep 21, 3:25 AM MDT	Lake Wind Advisory	GGW	16 hr
Sep 24, 8:05 PM MDT	Fire Weather Watch	GGW	19 hr
Sep 25, 2:47 PM MDT	Lake Wind Advisory	GGW	30 hr
Sep 25, 3:00 PM MDT	Red Flag Warning	GGW	30 hr
Sep 26, 9:03 PM MDT	Lake Wind Advisory	GGW	23 hr
Sep 28, 2:47 PM MDT	Lake Wind Advisory	GGW	25 hr
Sep 30, 3:53 AM MDT	Lake Wind Advisory	GGW	39 hr
Oct 5, 3:23 AM MDT	Lake Wind Advisory	GGW	12 hr
Oct 7, 12:36 AM MDT	Lake Wind Advisory	GGW	20 hr
Oct 9, 3:33 AM MDT	Lake Wind Advisory	GGW	17 hr
Oct 12, 2:58 PM MDT	Lake Wind Advisory	GGW	45 hr
Oct 18, 4:05 AM MDT	Lake Wind Advisory	GGW	15 hr
Oct 25, 2:26 PM MDT	Lake Wind Advisory	GGW	4 hr
Oct 27, 3:37 AM MDT	Lake Wind Advisory	GGW	15 hr
Oct 30, 3:28 AM MDT	Lake Wind Advisory	GGW	16 hr
Oct 31, 3:47 AM MDT	Lake Wind Advisory	GGW	14 hr
Nov 1, 2:36 AM MST	Lake Wind Advisory	GGW	10 hr
Nov 3, 3:21 AM MST	Lake Wind Advisory	GGW	14 hr
Nov 5, 2:34 PM MST	Lake Wind Advisory	GGW	28 hr
Nov 8, 2:54 AM MST	Lake Wind Advisory	GGW	15 hr
Nov 10, 3:23 AM MST	Lake Wind Advisory	GGW	9 hr
Nov 20, 2:42 PM MST	Lake Wind Advisory	GGW	26 hr
Nov 24, 3:39 AM MST	Lake Wind Advisory	GGW	13 hr
Nov 29, 6:40 AM MST	Dense Fog Advisory	GGW	2 hr
Nov 30, 3:03 PM MST	Lake Wind Advisory	GGW	26 hr
Dec 4, 2:56 AM MST	Dense Fog Advisory	GGW	7 hr
Dec 9, 2:55 PM MST	Wind Chill Advisory	GGW	18 hr
Dec 11, 3:06 PM MST	Winter Storm Watch	GGW	13 hr
Dec 12, 4:19 AM MST	Wind Chill Warning	GGW	24 hr
Dec 12, 4:19 AM MST	Winter Weather Advisory	GGW	37 hr
Dec 14, 4:25 PM MST	Wind Chill Advisory	GGW	12 hr
Dec 15, 5:09 AM MST	Wind Chill Advisory	GGW	6 hr
Dec 15, 11:15 AM MST	Wind Chill Advisory	GGW	105 min
Dec 15, 1:05 PM MST	Wind Chill Advisory	GGW	105 min
Dec 16, 2:26 PM MST	Freezing Rain Advisory	GGW	5 hr
Dec 17, 2:59 AM MST	Dense Fog Advisory	GGW	7 hr
Dec 20, 7:52 AM MST	Dense Fog Advisory	GGW	13 hr
Dec 20, 3:51 PM MST	Winter Weather Advisory	GGW	22 hr
Dec 22, 3:44 AM MST	Winter Storm Watch	GGW	23 hr
Dec 23, 3:01 AM MST	Winter Weather Advisory	GGW	17 hr
Dec 23, 3:14 PM MST	Wind Chill Advisory	GGW	68 hr
Dec 30, 2:21 PM MST	Wind Chill Advisory	GGW	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	26
Tornado Warning	5
Severe Thunderstorm Watch	6
Tornado Watch	1
Mesoscale Discussion	8
Special Weather Statement	2
Flooding
Areal Flood Advisory	1
Winter
Blizzard Warning	1
Ice Storm Warning	1
Winter Storm Warning	1
Winter Storm Watch	5
Freezing Rain Advisory	2
Winter Weather Advisory	18
Cold
Wind Chill Warning	1
Wind Chill Advisory	15
Wind and dust
High Wind Warning	3
High Wind Watch	1
Lake Wind Advisory	61
Fire
Red Flag Warning	8
Fire Weather Watch	4
Fog and smoke
Dense Fog Advisory	8

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2008 2010

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.