Alert archive / Montana / Sanders County

Weather alerts in Sanders County, Montana, 2011

122 weather alerts in 2011, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Sanders County and its neighbors

Each county as a circle sized by its count in 2011. Tap one for its archive.

Alerts: 122
Warnings: 20
Watches: 9
Advisories: 89
Busiest month: January22 alerts
Busiest day: January 28, 20113 alerts

Over time

By month

Warning verification

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

Sanders County, 2011

	Warnings	With a report	False alarm ratio
Tornado warnings	0
Severe thunderstorm warnings	3	2	33%
Flash flood warnings	0

Each office's whole area, 2011

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Missoula, MT: severe thunderstorm warnings	17	9	47%	25	60%	16 min
NWS Missoula, 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 2, 1:02 PM MST	Winter Weather Advisory	MSO	19 hr
Jan 4, 2:49 PM MST	Winter Weather Advisory	MSO	20 hr
Jan 7, 4:00 AM MST	Winter Weather Advisory	MSO	64 hr
Jan 10, 2:07 PM MST	Winter Storm Watch	MSO	14 hr
Jan 11, 3:58 AM MST	Winter Storm Warning	MSO	61 hr
Jan 11, 3:58 AM MST	Winter Weather Advisory	MSO	11 hr
Jan 13, 10:07 PM MST	Freezing Rain Advisory	MSO	11 hr
Jan 17, 9:17 AM MST	Areal Flood Advisory	MSO	24 hr
Jan 18, 3:21 AM MST	Winter Weather Advisory	MSO	30 hr
Jan 20, 3:41 PM MST	Winter Weather Advisory	MSO	4 hr
Jan 21, 3:29 AM MST	Winter Weather Advisory	MSO	26 hr
Jan 24, 6:07 AM MST	Dense Fog Advisory	MSO	5 hr
Jan 24, 5:51 PM MST	Freezing Rain Advisory	MSO	5 hr
Jan 24, 10:51 PM MST	Winter Weather Advisory	MSO	12 hr
Jan 26, 1:36 AM MST	Dense Fog Advisory	MSO	2 hr
Jan 26, 3:47 AM MST	Dense Fog Advisory	MSO	9 hr
Jan 27, 3:46 AM MST	Dense Fog Advisory	MSO	9 hr
Jan 27, 6:09 PM MST	Dense Fog Advisory	MSO	15 hr
Jan 28, 3:21 AM MST	Winter Storm Watch	MSO	23 hr
Jan 28, 3:03 PM MST	Winter Weather Advisory	MSO	55 hr
Jan 29, 2:45 AM MST	Winter Storm Warning	MSO	38 hr
Jan 30, 3:00 PM MST	Wind Chill Warning	MSO	22 hr
Feb 3, 1:32 PM MST	Winter Weather Advisory	MSO	30 hr
Feb 6, 4:13 AM MST	Winter Storm Warning	MSO	53 hr
Feb 6, 4:13 AM MST	Winter Weather Advisory	MSO	61 hr
Feb 7, 11:02 PM MST	Wind Chill Advisory	MSO	10 hr
Feb 11, 2:03 PM MST	Wind Advisory	MSO	44 hr
Feb 12, 4:09 AM MST	High Wind Warning	MSO	29 hr
Feb 14, 1:53 PM MST	Winter Storm Warning	MSO	57 hr
Feb 14, 1:53 PM MST	Winter Weather Advisory	MSO	3 days
Feb 18, 7:25 AM MST	Winter Weather Advisory	MSO	3 hr
Feb 19, 6:14 PM MST	Winter Weather Advisory	MSO	34 hr
Feb 21, 4:31 AM MST	Winter Weather Advisory	MSO	52 hr
Feb 21, 2:36 PM MST	Winter Storm Warning	MSO	72 hr
Feb 23, 5:18 AM MST	Winter Weather Advisory	MSO	54 hr
Feb 24, 7:34 AM MST	Wind Chill Warning	MSO	25 hr
Feb 24, 10:50 AM MST	Wind Chill Advisory	MSO	11 hr
Feb 25, 1:22 PM MST	Winter Storm Watch	MSO	25 hr
Feb 26, 1:58 PM MST	Winter Storm Warning	MSO	3 days
Feb 28, 1:21 PM MST	Winter Weather Advisory	MSO	22 hr
Mar 9, 4:57 AM MST	Dense Fog Advisory	MSO	6 hr
Mar 10, 9:56 AM MST	Winter Weather Advisory	MSO	23 hr
Mar 14, 3:06 AM MDT	Winter Weather Advisory	MSO	5 hr
Mar 14, 2:37 PM MDT	Winter Weather Advisory	MSO	42 hr
Mar 16, 9:06 AM MDT	Lake Wind Advisory	MSO	9 hr
Mar 20, 3:19 AM MDT	Dense Fog Advisory	MSO	8 hr
Mar 21, 3:14 AM MDT	Winter Weather Advisory	MSO	33 hr
Mar 29, 2:10 PM MDT	Lake Wind Advisory	MSO	20 hr
Mar 30, 10:30 AM MDT	Lake Wind Advisory	MSO	7 hr
Mar 31, 9:43 AM MDT	Lake Wind Advisory	MSO	7 hr
Apr 1, 11:31 AM MDT	Winter Weather Advisory	MSO	48 hr
Apr 2, 3:38 PM MDT	Lake Wind Advisory	MSO	4 hr
Apr 3, 2:37 PM MDT	Winter Weather Advisory	MSO	45 hr
Apr 5, 3:55 AM MDT	Lake Wind Advisory	MSO	16 hr
Apr 5, 2:13 PM MDT	Winter Weather Advisory	MSO	3 days
Apr 10, 1:59 PM MDT	Winter Weather Advisory	MSO	31 hr
Apr 14, 2:01 PM MDT	Winter Weather Advisory	MSO	22 hr
Apr 15, 1:59 PM MDT	Winter Weather Advisory	MSO	20 hr
Apr 18, 12:49 PM MDT	Winter Weather Advisory	MSO	21 hr
Apr 20, 2:13 PM MDT	Winter Weather Advisory	MSO	44 hr
Apr 25, 2:22 PM MDT	Winter Weather Advisory	MSO	20 hr
May 12, 9:32 PM MDT	Flood Watch	MSO	5 days
May 14, 3:15 AM MDT	Wind Advisory	MSO	19 hr
May 15, 7:50 AM MDT	Areal Flood Warning	MSO	59 hr
May 24, 1:24 PM MDT	Areal Flood Advisory	MSO	72 hr
May 25, 3:12 AM MDT	Winter Weather Advisory	MSO	54 hr
May 27, 1:13 PM MDT	Areal Flood Advisory	MSO	21 hr
Jun 6, 10:40 AM MDT	Flood Watch	MSO	71 hr
Jun 7, 10:04 AM MDT	Areal Flood Warning	MSO	10 days
Jun 14, 3:03 PM MDT	Lake Wind Advisory	MSO	30 hr
Jun 22, 12:16 PM MDT	Flood Watch	MSO	68 hr
Jun 23, 12:16 PM MDT	Mesoscale Discussion	SPC	59 min
Jun 25, 8:30 AM MDT	Areal Flood Warning	MSO	35 hr
Jun 29, 12:04 PM MDT	Lake Wind Advisory	MSO	6 hr
Jun 30, 7:30 AM MDT	Lake Wind Advisory	MSO	10 hr
Jul 7, 11:43 AM MDT	Wind Advisory	MSO	33 hr
Jul 12, 11:24 PM MDT	Special Weather Statement	MSO	36 min
Jul 19, 5:30 PM MDT	Severe Thunderstorm Warning	MSO	30 min
Jul 25, 5:02 PM MDT	Special Weather Statement	MSO	28 min
Jul 25, 5:23 PM MDT	Severe Thunderstorm Warning	MSO	52 min
Jul 25, 5:48 PM MDT	Severe Thunderstorm Warning	MSO	42 min
Jul 25, 7:00 PM MDT	Special Weather Statement	MSO	45 min
Sep 2, 7:12 AM MDT	Lake Wind Advisory	MSO	6 hr
Sep 2, 1:32 PM MDT	Frost Advisory	MSO	19 hr
Sep 3, 2:19 PM MDT	Frost Advisory	MSO	19 hr
Sep 19, 9:43 AM MDT	Lake Wind Advisory	MSO	10 hr
Sep 20, 2:22 PM MDT	Frost Advisory	MSO	19 hr
Sep 26, 2:45 PM MDT	Lake Wind Advisory	MSO	31 hr
Oct 8, 6:14 AM MDT	Dense Fog Advisory	MSO	4 hr
Oct 17, 1:10 AM MDT	Dense Fog Advisory	MSO	9 hr
Oct 19, 7:50 AM MDT	Dense Fog Advisory	MSO	3 hr
Nov 9, 2:11 PM MST	Winter Storm Watch	MSO	22 hr
Nov 10, 12:24 PM MST	Winter Storm Warning	MSO	45 hr
Nov 10, 12:24 PM MST	Winter Weather Advisory	MSO	45 hr
Nov 10, 2:02 PM MST	Lake Wind Advisory	MSO	24 hr
Nov 11, 2:16 PM MST	Lake Wind Advisory	MSO	13 hr
Nov 12, 9:14 AM MST	Lake Wind Advisory	MSO	11 hr
Nov 12, 1:50 PM MST	Winter Weather Advisory	MSO	69 hr
Nov 13, 7:57 AM MST	Lake Wind Advisory	MSO	12 hr
Nov 15, 2:10 PM MST	Winter Storm Watch	MSO	14 hr
Nov 16, 3:54 AM MST	Winter Storm Warning	MSO	43 hr
Nov 17, 4:48 AM MST	Winter Weather Advisory	MSO	6 hr
Nov 17, 2:36 PM MST	Winter Weather Advisory	MSO	38 hr
Nov 18, 8:31 AM MST	Winter Storm Warning	MSO	20 hr
Nov 20, 2:48 PM MST	Winter Weather Advisory	MSO	13 hr
Nov 21, 3:42 AM MST	Winter Storm Warning	MSO	7 hr
Nov 21, 10:27 AM MST	Winter Weather Advisory	MSO	31 hr
Nov 23, 1:48 PM MST	Winter Weather Advisory	MSO	48 hr
Nov 28, 2:44 PM MST	Winter Storm Watch	MSO	14 hr
Nov 29, 4:38 AM MST	Winter Storm Warning	MSO	36 hr
Nov 29, 4:38 AM MST	Winter Weather Advisory	MSO	36 hr
Dec 8, 8:26 AM MST	Dense Fog Advisory	MSO	4 hr
Dec 9, 2:47 PM MST	Dense Fog Advisory	MSO	20 hr
Dec 10, 2:44 PM MST	Dense Fog Advisory	MSO	17 hr
Dec 11, 8:08 AM MST	Winter Weather Advisory	MSO	4 hr
Dec 17, 7:35 PM MST	Dense Fog Advisory	MSO	9 hr
Dec 20, 2:45 PM MST	Winter Weather Advisory	MSO	24 hr
Dec 24, 7:37 AM MST	Winter Weather Advisory	MSO	3 hr
Dec 24, 2:03 PM MST	Winter Weather Advisory	MSO	6 hr
Dec 25, 6:24 AM MST	Freezing Fog Advisory	MSO	6 hr
Dec 27, 3:15 AM MST	Winter Weather Advisory	MSO	57 hr
Dec 29, 2:30 PM MST	Winter Weather Advisory	MSO	42 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	3
Mesoscale Discussion	1
Special Weather Statement	3
Flooding
Areal Flood Warning	3
Flood Watch	3
Areal Flood Advisory	3
Winter
Winter Storm Warning	11
Winter Storm Watch	6
Freezing Rain Advisory	2
Winter Weather Advisory	45
Cold
Wind Chill Warning	2
Frost Advisory	3
Wind Chill Advisory	2
Wind and dust
High Wind Warning	1
Lake Wind Advisory	16
Wind Advisory	3
Fog and smoke
Dense Fog Advisory	14
Freezing Fog Advisory	1

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2010 2012

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.