Alert archive / Montana / Sweet Grass County

Weather alerts in Sweet Grass County, Montana, 2021

133 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Sweet Grass County and its neighbors

Each county as a circle sized by its count in 2021. Tap one for its archive.

Alerts: 133
Warnings: 38
Watches: 23
Advisories: 42
Busiest month: December26 alerts
Busiest day: June 5, 20215 alerts

Over time

By month

Warning verification

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

Sweet Grass County, 2021

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	0			0
Severe thunderstorm warnings	2	2	0%	3	33%	11 min
Flash flood warnings	0			0

Each office's whole area, 2021

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Billings, MT: severe thunderstorm warnings	51	23	55%	84	42%	18 min
NWS Billings, MT: flash flood warnings	2	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, 3:03 AM MST	Wind Advisory	BYZ	63 hr
Jan 1, 1:19 PM MST	High Wind Warning	BYZ	53 hr
Jan 3, 2:30 PM MST	Special Weather Statement	BYZ	2 hr
Jan 7, 5:23 PM MST	Winter Weather Advisory	BYZ	16 hr
Jan 11, 3:04 AM MST	High Wind Watch	BYZ	34 hr
Jan 11, 11:45 AM MST	Wind Advisory	BYZ	25 hr
Jan 12, 2:51 AM MST	High Wind Warning	BYZ	65 hr
Jan 12, 12:06 PM MST	Winter Storm Warning	BYZ	34 hr
Jan 18, 2:43 PM MST	High Wind Watch	BYZ	12 hr
Jan 19, 2:36 AM MST	High Wind Warning	BYZ	35 hr
Jan 19, 2:36 AM MST	Wind Advisory	BYZ	35 hr
Jan 20, 2:06 PM MST	Winter Weather Advisory	BYZ	45 hr
Feb 2, 1:20 AM MST	Winter Weather Advisory	BYZ	43 hr
Feb 3, 2:50 PM MST	Winter Storm Watch	BYZ	37 hr
Feb 4, 9:28 AM MST	Winter Storm Warning	BYZ	3 days
Feb 6, 3:26 AM MST	Wind Chill Advisory	BYZ	10 days
Feb 7, 3:48 AM MST	Winter Weather Advisory	BYZ	24 hr
Feb 14, 2:24 AM MST	Winter Weather Advisory	BYZ	48 hr
Feb 18, 1:24 AM MST	Wind Advisory	BYZ	34 hr
Feb 19, 11:08 AM MST	High Wind Watch	BYZ	16 hr
Feb 20, 3:00 AM MST	High Wind Warning	BYZ	4 days
Feb 21, 12:24 PM MST	Special Weather Statement	BYZ	3 hr
Feb 24, 3:01 AM MST	High Wind Watch	BYZ	11 hr
Feb 24, 3:01 AM MST	Wind Advisory	BYZ	57 hr
Feb 24, 1:38 PM MST	High Wind Warning	BYZ	49 hr
Feb 28, 7:57 AM MST	High Wind Warning	BYZ	12 hr
Mar 19, 1:06 PM MDT	Winter Storm Warning	BYZ	37 hr
Mar 19, 7:06 PM MDT	Winter Weather Advisory	BYZ	31 hr
Mar 22, 2:30 AM MDT	Winter Weather Advisory	BYZ	43 hr
Mar 24, 7:35 AM MDT	Special Weather Statement	BYZ	115 min
Mar 24, 12:03 PM MDT	Winter Weather Advisory	BYZ	63 hr
Mar 27, 3:15 AM MDT	High Wind Watch	BYZ	23 hr
Mar 28, 2:27 AM MDT	High Wind Warning	BYZ	40 hr
Mar 29, 5:52 AM MDT	Special Weather Statement	BYZ	113 min
Apr 4, 1:43 PM MDT	Winter Weather Advisory	BYZ	49 hr
Apr 14, 2:06 AM MDT	Winter Weather Advisory	BYZ	58 hr
Apr 17, 2:09 AM MDT	Winter Storm Watch	BYZ	13 hr
Apr 17, 3:31 PM MDT	Winter Storm Warning	BYZ	45 hr
Apr 22, 2:19 AM MDT	Winter Weather Advisory	BYZ	32 hr
May 7, 2:25 PM MDT	Mesoscale Discussion	SPC	2 hr
Jun 4, 1:59 PM MDT	Mesoscale Discussion	SPC	2 hr
Jun 4, 4:01 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 4, 4:55 PM MDT	Severe Thunderstorm Warning	BYZ	35 min
Jun 4, 8:10 PM MDT	Mesoscale Discussion	SPC	2 hr
Jun 4, 9:00 PM MDT	Special Weather Statement	BYZ	30 min
Jun 4, 10:28 PM MDT	Special Weather Statement	BYZ	32 min
Jun 5, 2:26 PM MDT	Special Weather Statement	BYZ	34 min
Jun 5, 2:27 PM MDT	Mesoscale Discussion	SPC	2 hr
Jun 10, 1:47 PM MDT	Mesoscale Discussion	SPC	88 min
Jun 10, 4:26 PM MDT	Special Weather Statement	BYZ	109 min
Jun 10, 6:10 PM MDT	Special Weather Statement	BYZ	95 min
Jun 10, 7:45 PM MDT	Special Weather Statement	BYZ	2 hr
Jun 14, 9:26 AM MDT	Red Flag Warning	BYZ	43 hr
Jun 14, 2:27 PM MDT	Mesoscale Discussion	SPC	2 hr
Jun 18, 2:46 AM MDT	Fire Weather Watch	BYZ	11 hr
Jun 18, 2:00 PM MDT	Red Flag Warning	BYZ	31 hr
Jun 23, 4:33 PM MDT	Mesoscale Discussion	SPC	117 min
Jul 7, 2:03 PM MDT	Mesoscale Discussion	SPC	117 min
Jul 7, 3:03 PM MDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 7, 5:26 PM MDT	Special Weather Statement	BYZ	49 min
Jul 7, 5:48 PM MDT	Mesoscale Discussion	SPC	117 min
Jul 7, 5:49 PM MDT	Severe Thunderstorm Warning	BYZ	56 min
Jul 9, 2:20 PM MDT	Mesoscale Discussion	SPC	85 min
Jul 16, 3:14 PM MDT	Heat Advisory	BYZ	3 days
Jul 18, 3:10 PM MDT	Red Flag Warning	BYZ	57 hr
Jul 21, 1:39 PM MDT	Fire Weather Watch	BYZ	24 hr
Jul 22, 1:40 PM MDT	Red Flag Warning	BYZ	31 hr
Jul 22, 1:50 PM MDT	Mesoscale Discussion	SPC	2 hr
Jul 24, 12:18 PM MDT	Excessive Heat Watch	BYZ	25 hr
Jul 25, 1:39 PM MDT	Excessive Heat Warning	BYZ	58 hr
Aug 5, 5:48 PM MDT	Special Weather Statement	BYZ	42 min
Aug 7, 3:06 AM MDT	Fire Weather Watch	BYZ	11 hr
Aug 7, 2:26 PM MDT	Red Flag Warning	BYZ	34 hr
Aug 9, 2:58 AM MDT	Fire Weather Watch	BYZ	10 hr
Aug 9, 12:55 PM MDT	Red Flag Warning	BYZ	57 hr
Aug 14, 3:08 AM MDT	Fire Weather Watch	BYZ	11 hr
Aug 14, 2:07 PM MDT	Red Flag Warning	BYZ	3 days
Aug 16, 2:49 PM MDT	Mesoscale Discussion	SPC	116 min
Aug 17, 2:21 PM MDT	Mesoscale Discussion	SPC	114 min
Sep 4, 2:20 PM MDT	Fire Weather Watch	BYZ	24 hr
Sep 5, 2:29 PM MDT	Red Flag Warning	BYZ	30 hr
Sep 14, 1:04 PM MDT	Red Flag Warning	BYZ	31 hr
Sep 16, 1:53 PM MDT	Red Flag Warning	BYZ	55 hr
Sep 26, 2:41 AM MDT	Fire Weather Watch	BYZ	10 hr
Sep 26, 12:59 PM MDT	Red Flag Warning	BYZ	32 hr
Sep 27, 1:50 AM MDT	Fire Weather Watch	BYZ	12 hr
Sep 27, 2:06 PM MDT	Red Flag Warning	BYZ	31 hr
Oct 9, 1:08 PM MDT	Winter Storm Watch	BYZ	38 hr
Oct 10, 2:47 PM MDT	Winter Storm Warning	BYZ	3 days
Oct 25, 1:31 PM MDT	High Wind Watch	BYZ	36 hr
Oct 27, 1:53 AM MDT	High Wind Warning	BYZ	18 hr
Oct 27, 1:53 AM MDT	Wind Advisory	BYZ	18 hr
Oct 29, 2:50 AM MDT	Wind Advisory	BYZ	19 hr
Oct 30, 11:51 PM MDT	Winter Weather Advisory	BYZ	9 hr
Nov 12, 2:05 AM MST	High Wind Watch	BYZ	12 hr
Nov 12, 2:05 AM MST	Wind Advisory	BYZ	32 hr
Nov 12, 1:58 PM MST	High Wind Warning	BYZ	28 hr
Nov 14, 2:15 AM MST	High Wind Warning	BYZ	61 hr
Nov 14, 2:15 AM MST	Wind Advisory	BYZ	63 hr
Nov 15, 2:44 AM MST	High Wind Warning	BYZ	39 hr
Nov 20, 11:50 AM MST	Wind Advisory	BYZ	61 hr
Nov 24, 12:16 AM MST	Wind Advisory	BYZ	63 hr
Nov 24, 3:56 AM MST	Special Weather Statement	BYZ	4 hr
Nov 25, 2:26 AM MST	High Wind Warning	BYZ	37 hr
Nov 27, 2:39 AM MST	Wind Advisory	BYZ	50 hr
Nov 29, 2:04 PM MST	High Wind Warning	BYZ	67 hr
Nov 29, 2:04 PM MST	Wind Advisory	BYZ	41 hr
Dec 3, 1:53 PM MST	Wind Advisory	BYZ	31 hr
Dec 4, 2:08 AM MST	High Wind Warning	BYZ	23 hr
Dec 4, 1:55 PM MST	Winter Weather Advisory	BYZ	22 hr
Dec 5, 5:45 AM MST	Special Weather Statement	BYZ	2 hr
Dec 6, 1:18 AM MST	Winter Weather Advisory	BYZ	32 hr
Dec 6, 2:37 PM MST	Special Weather Statement	BYZ	83 min
Dec 7, 1:41 AM MST	Wind Advisory	BYZ	40 hr
Dec 7, 9:13 PM MST	High Wind Warning	BYZ	21 hr
Dec 9, 2:14 PM MST	Wind Advisory	BYZ	41 hr
Dec 10, 1:46 AM MST	High Wind Watch	BYZ	12 hr
Dec 10, 2:04 PM MST	High Wind Warning	BYZ	51 hr
Dec 13, 7:51 AM MST	Wind Advisory	BYZ	31 hr
Dec 13, 2:37 PM MST	Winter Weather Advisory	BYZ	50 hr
Dec 17, 11:59 AM MST	Winter Weather Advisory	BYZ	27 hr
Dec 18, 2:40 PM MST	High Wind Warning	BYZ	25 hr
Dec 18, 2:41 PM MST	Winter Weather Advisory	BYZ	44 hr
Dec 20, 2:30 AM MST	Wind Advisory	BYZ	4 days
Dec 20, 2:44 PM MST	Winter Weather Advisory	BYZ	12 hr
Dec 21, 3:29 PM MST	Winter Storm Watch	BYZ	22 hr
Dec 22, 1:52 PM MST	Winter Storm Warning	BYZ	54 hr
Dec 26, 4:06 AM MST	Winter Weather Advisory	BYZ	17 hr
Dec 26, 4:59 AM MST	Special Weather Statement	BYZ	3 hr
Dec 26, 8:00 AM MST	Special Weather Statement	BYZ	90 min
Dec 26, 6:39 PM MST	Wind Chill Advisory	BYZ	41 hr
Dec 30, 2:47 AM MST	Winter Weather Advisory	BYZ	32 hr
Dec 30, 12:30 PM MST	Winter Weather Advisory	BYZ	27 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	2
Severe Thunderstorm Watch	2
Mesoscale Discussion	13
Special Weather Statement	17
Winter
Winter Storm Warning	6
Winter Storm Watch	4
Winter Weather Advisory	21
Heat
Excessive Heat Warning	1
Excessive Heat Watch	1
Heat Advisory	1
Cold
Wind Chill Advisory	2
Wind and dust
High Wind Warning	17
High Wind Watch	8
Wind Advisory	18
Fire
Red Flag Warning	12
Fire Weather Watch	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 2020 2022

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.