Alert archive / Massachusetts / Plymouth County

Weather alerts in Plymouth County, Massachusetts, 2021

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

Plymouth County and its neighbors

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

Alerts: 191
Warnings: 54
Watches: 21
Advisories: 54
Busiest month: July42 alerts
Busiest day: September 2, 202111 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 warnings covering Plymouth County in 2021 had a tornado report inside them.

Plymouth County, 2021

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	1	0	100%	0
Severe thunderstorm warnings	27	17	37%	13	85%	26 min
Flash flood warnings	4	0	100%	0

Each office's whole area, 2021

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Boston/Norton, MA: tornado warnings	23	6	74%	14	50%	18 min
NWS Boston/Norton, MA: severe thunderstorm warnings	131	84	36%	358	80%	27 min
NWS Boston/Norton, MA: flash flood warnings	38	1	97%	5	60%	141 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, Eastern Time. Each opens its own page with the text, the map, the radar and the sounding.

Issued	Product	Office	Lasted
Jan 5, 3:48 AM EST	Coastal Flood Statement	BOX	14 hr
Jan 5, 7:54 PM EST	Coastal Flood Statement	BOX	11 hr
Jan 15, 3:35 PM EST	Coastal Flood Advisory	BOX	23 hr
Jan 16, 3:03 AM EST	Wind Advisory	BOX	9 hr
Jan 25, 3:02 PM EST	Winter Weather Advisory	BOX	37 hr
Jan 30, 3:28 PM EST	Winter Storm Watch	BOX	24 hr
Jan 31, 3:37 PM EST	Winter Storm Warning	BOX	37 hr
Jan 31, 3:52 PM EST	Coastal Flood Watch	BOX	12 hr
Feb 1, 3:31 AM EST	Coastal Flood Advisory	BOX	37 hr
Feb 1, 1:43 PM EST	Mesoscale Discussion	SPC	6 hr
Feb 1, 7:24 PM EST	Winter Weather Advisory	BOX	6 hr
Feb 1, 10:31 PM EST	Wind Advisory	BOX	6 hr
Feb 2, 7:03 PM EST	Coastal Flood Advisory	BOX	10 hr
Feb 5, 3:27 PM EST	Winter Storm Watch	BOX	24 hr
Feb 6, 3:20 AM EST	Winter Storm Warning	BOX	42 hr
Feb 7, 11:40 AM EST	Mesoscale Discussion	SPC	4 hr
Feb 8, 2:56 PM EST	Winter Weather Advisory	BOX	28 hr
Feb 13, 4:20 PM EST	Winter Weather Advisory	BOX	17 hr
Feb 15, 3:54 AM EST	Winter Weather Advisory	BOX	31 hr
Feb 16, 3:38 PM EST	Winter Storm Watch	BOX	24 hr
Feb 17, 3:37 PM EST	Winter Weather Advisory	BOX	56 hr
Feb 28, 3:01 PM EST	Wind Advisory	BOX	48 hr
Mar 1, 8:38 AM EST	Coastal Flood Statement	BOX	5 hr
Mar 12, 2:53 AM EST	Wind Advisory	BOX	28 hr
Mar 12, 1:30 PM EST	Red Flag Warning	BOX	28 hr
Mar 13, 3:42 PM EST	Wind Advisory	BOX	35 hr
Mar 14, 3:10 AM EDT	Red Flag Warning	BOX	17 hr
Mar 14, 5:22 PM EDT	Special Weather Statement	BOX	53 min
Mar 15, 10:48 AM EDT	Red Flag Warning	BOX	10 hr
Mar 17, 3:46 PM EDT	Wind Advisory	BOX	43 hr
Mar 25, 3:57 PM EDT	Wind Advisory	BOX	36 hr
Mar 25, 7:57 PM EDT	Dense Fog Advisory	BOX	16 hr
Mar 28, 3:34 AM EDT	Wind Advisory	BOX	36 hr
Mar 28, 4:20 PM EDT	Dense Fog Advisory	BOX	4 hr
Apr 11, 2:39 AM EDT	Dense Fog Advisory	BOX	7 hr
Apr 21, 4:13 PM EDT	Freeze Watch	BOX	24 hr
Apr 22, 4:08 PM EDT	Freeze Warning	BOX	12 hr
Apr 28, 4:16 AM EDT	Coastal Flood Statement	BOX	23 hr
Apr 28, 2:50 PM EDT	Coastal Flood Advisory	BOX	12 hr
Apr 29, 3:24 PM EDT	Wind Advisory	BOX	35 hr
Apr 29, 3:29 PM EDT	Coastal Flood Statement	BOX	13 hr
May 23, 1:20 PM EDT	Mesoscale Discussion	SPC	115 min
May 28, 3:46 AM EDT	Coastal Flood Statement	BOX	24 hr
May 29, 4:03 AM EDT	Coastal Flood Statement	BOX	12 hr
May 29, 3:52 PM EDT	Coastal Flood Advisory	BOX	12 hr
Jun 4, 10:48 PM EDT	Dense Fog Advisory	BOX	10 hr
Jun 6, 3:29 AM EDT	Heat Advisory	BOX	64 hr
Jun 7, 3:12 PM EDT	Heat Advisory	BOX	28 hr
Jun 8, 5:59 PM EDT	Severe Thunderstorm Warning	BOX	35 min
Jun 9, 3:12 AM EDT	Heat Advisory	BOX	17 hr
Jun 9, 3:19 PM EDT	Mesoscale Discussion	SPC	116 min
Jun 15, 2:38 PM EDT	Mesoscale Discussion	SPC	2 hr
Jun 22, 2:00 PM EDT	Severe Thunderstorm Warning	BOX	45 min
Jun 22, 2:33 PM EDT	Special Weather Statement	BOX	42 min
Jun 22, 2:43 PM EDT	Special Weather Statement	BOX	32 min
Jun 22, 3:06 PM EDT	Severe Thunderstorm Warning	BOX	23 min
Jun 26, 3:15 PM EDT	Heat Advisory	BOX	4 days
Jun 29, 6:03 PM EDT	Special Weather Statement	BOX	42 min
Jun 30, 2:16 PM EDT	Mesoscale Discussion	SPC	119 min
Jun 30, 3:21 PM EDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 30, 6:12 PM EDT	Severe Thunderstorm Warning	BOX	47 min
Jun 30, 6:58 PM EDT	Mesoscale Discussion	SPC	92 min
Jun 30, 8:14 PM EDT	Severe Thunderstorm Warning	BOX	46 min
Jun 30, 8:31 PM EDT	Severe Thunderstorm Warning	BOX	59 min
Jul 1, 4:01 PM EDT	Special Weather Statement	BOX	59 min
Jul 2, 4:24 AM EDT	Rip Current Statement	BOX	16 hr
Jul 2, 7:57 PM EDT	Rip Current Statement	BOX	24 hr
Jul 3, 3:38 PM EDT	Special Weather Statement	BOX	52 min
Jul 6, 3:33 AM EDT	Heat Advisory	BOX	39 hr
Jul 6, 1:13 PM EDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 6, 4:23 PM EDT	Mesoscale Discussion	SPC	97 min
Jul 6, 6:13 PM EDT	Severe Thunderstorm Warning	BOX	31 min
Jul 6, 6:45 PM EDT	Special Weather Statement	BOX	45 min
Jul 7, 2:41 PM EDT	Severe Thunderstorm Watch	SPC	10 hr
Jul 7, 4:48 PM EDT	Mesoscale Discussion	SPC	87 min
Jul 7, 5:10 PM EDT	Tropical Storm Watch	BOX	13 hr
Jul 7, 6:59 PM EDT	Severe Thunderstorm Warning	BOX	61 min
Jul 7, 7:47 PM EDT	Severe Thunderstorm Warning	BOX	25 min
Jul 8, 3:42 AM EDT	Special Weather Statement	BOX	48 min
Jul 8, 4:20 AM EDT	Flash Flood Watch	BOX	36 hr
Jul 8, 4:57 AM EDT	Tropical Storm Warning	BOX	36 hr
Jul 9, 9:32 AM EDT	Flash Flood Warning	BOX	6 hr
Jul 9, 3:24 PM EDT	Areal Flood Warning	BOX	5 hr
Jul 11, 3:34 PM EDT	Flash Flood Watch	BOX	21 hr
Jul 14, 12:32 AM EDT	Dense Fog Advisory	BOX	9 hr
Jul 14, 10:05 PM EDT	Dense Fog Advisory	BOX	11 hr
Jul 16, 9:38 AM EDT	Heat Advisory	BOX	9 hr
Jul 16, 5:47 PM EDT	Severe Thunderstorm Warning	BOX	33 min
Jul 17, 2:45 PM EDT	Special Weather Statement	BOX	45 min
Jul 21, 11:56 AM EDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 21, 2:39 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 21, 8:30 PM EDT	Severe Thunderstorm Warning	BOX	30 min
Jul 21, 8:46 PM EDT	Special Weather Statement	BOX	44 min
Jul 21, 9:29 PM EDT	Special Weather Statement	BOX	46 min
Jul 23, 2:49 PM EDT	Coastal Flood Statement	BOX	11 hr
Jul 23, 5:47 PM EDT	Mesoscale Discussion	SPC	58 min
Jul 23, 6:09 PM EDT	Severe Thunderstorm Warning	BOX	26 min
Jul 23, 6:25 PM EDT	Special Weather Statement	BOX	50 min
Jul 23, 6:42 PM EDT	Severe Thunderstorm Warning	BOX	48 min
Jul 23, 7:28 PM EDT	Severe Thunderstorm Warning	BOX	34 min
Jul 27, 2:47 PM EDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 27, 6:09 PM EDT	Mesoscale Discussion	SPC	96 min
Jul 27, 6:33 PM EDT	Severe Thunderstorm Warning	BOX	57 min
Jul 27, 7:26 PM EDT	Severe Thunderstorm Warning	BOX	64 min
Aug 4, 3:11 AM EDT	Flash Flood Watch	BOX	34 hr
Aug 5, 12:12 AM EDT	Special Weather Statement	BOX	48 min
Aug 5, 5:27 AM EDT	Areal Flood Warning	BOX	7 hr
Aug 5, 6:52 AM EDT	Areal Flood Warning	BOX	6 hr
Aug 10, 3:22 AM EDT	Excessive Heat Watch	BOX	60 hr
Aug 10, 3:22 AM EDT	Heat Advisory	BOX	41 hr
Aug 11, 3:28 PM EDT	Excessive Heat Warning	BOX	29 hr
Aug 11, 3:28 PM EDT	Heat Advisory	BOX	29 hr
Aug 11, 7:49 PM EDT	Dense Fog Advisory	BOX	10 hr
Aug 12, 2:53 PM EDT	Heat Advisory	BOX	29 hr
Aug 12, 6:44 PM EDT	Mesoscale Discussion	SPC	61 min
Aug 12, 7:14 PM EDT	Special Weather Statement	BOX	61 min
Aug 14, 12:08 PM EDT	Severe Thunderstorm Warning	BOX	27 min
Aug 19, 10:49 AM EDT	Mesoscale Discussion	SPC	86 min
Aug 20, 5:10 AM EDT	Hurricane Watch	BOX	30 hr
Aug 20, 5:10 AM EDT	Storm Surge Watch	BOX	12 hr
Aug 20, 5:03 PM EDT	Storm Surge Warning	BOX	45 hr
Aug 20, 11:09 PM EDT	Tropical Storm Warning	BOX	42 hr
Aug 22, 9:43 AM EDT	Coastal Flood Advisory	BOX	16 hr
Aug 25, 2:55 PM EDT	Heat Advisory	BOX	29 hr
Aug 26, 3:44 PM EDT	Heat Advisory	BOX	27 hr
Aug 30, 3:12 PM EDT	Flash Flood Watch	BOX	65 hr
Sep 1, 4:00 PM EDT	Wind Advisory	BOX	19 hr
Sep 1, 10:32 PM EDT	Flash Flood Warning	BOX	10 hr
Sep 1, 11:20 PM EDT	Mesoscale Discussion	SPC	85 min
Sep 1, 11:21 PM EDT	Tornado Warning	BOX	54 min
Sep 1, 11:37 PM EDT	Tornado Watch	SPC	7 hr
Sep 2, 2:34 AM EDT	Flash Flood Warning Considerable damage threat	BOX	6 hr
Sep 2, 5:26 AM EDT	Flash Flood Warning Considerable damage threat	BOX	3 hr
Sep 2, 7:04 AM EDT	Areal Flood Warning	BOX	11 hr
Sep 2, 7:43 AM EDT	Areal Flood Warning	BOX	6 hr
Sep 2, 7:54 AM EDT	Areal Flood Warning	BOX	6 hr
Sep 2, 9:25 AM EDT	River Flood Warning	BOX	64 hr
Sep 2, 1:42 PM EDT	Areal Flood Warning	BOX	6 hr
Sep 5, 2:37 AM EDT	River Flood Warning	BOX	13 hr
Sep 9, 2:57 AM EDT	Rip Current Statement	BOX	11 hr
Sep 9, 4:12 AM EDT	Mesoscale Discussion	SPC	3 hr
Sep 9, 1:55 PM EDT	High Surf Advisory	BOX	53 hr
Sep 9, 1:57 PM EDT	Special Weather Statement	BOX	63 min
Sep 16, 6:38 AM EDT	Severe Thunderstorm Warning	BOX	53 min
Sep 16, 7:13 AM EDT	Severe Thunderstorm Warning	BOX	62 min
Sep 17, 3:13 PM EDT	Rip Current Statement	BOX	53 hr
Sep 17, 8:10 PM EDT	Dense Fog Advisory	BOX	12 hr
Sep 23, 9:28 AM EDT	Rip Current Statement	BOX	35 hr
Sep 28, 10:02 AM EDT	Severe Thunderstorm Warning	BOX	43 min
Sep 28, 2:07 PM EDT	Severe Thunderstorm Warning	BOX	53 min
Oct 1, 3:14 AM EDT	Rip Current Statement	BOX	60 hr
Oct 8, 3:02 AM EDT	Coastal Flood Advisory	BOX	37 hr
Oct 10, 2:55 AM EDT	Coastal Flood Statement	BOX	13 hr
Oct 11, 3:43 AM EDT	Coastal Flood Statement	BOX	14 hr
Oct 11, 3:43 AM EDT	Rip Current Statement	BOX	16 hr
Oct 12, 1:11 AM EDT	Dense Fog Advisory	BOX	8 hr
Oct 16, 11:21 PM EDT	Mesoscale Discussion	SPC	54 min
Oct 22, 2:53 PM EDT	Frost Advisory	BOX	41 hr
Oct 24, 2:52 PM EDT	High Wind Watch	BOX	24 hr
Oct 25, 3:47 AM EDT	Flood Watch	BOX	52 hr
Oct 25, 3:12 PM EDT	High Wind Warning	BOX	48 hr
Oct 25, 3:19 PM EDT	Coastal Flood Advisory	BOX	40 hr
Oct 25, 3:19 PM EDT	Coastal Flood Advisory	BOX	52 hr
Oct 25, 11:24 PM EDT	Special Weather Statement	BOX	81 min
Oct 27, 7:53 AM EDT	Coastal Flood Warning	BOX	11 hr
Oct 27, 3:40 PM EDT	Wind Advisory	BOX	12 hr
Oct 31, 2:26 AM EDT	Severe Thunderstorm Warning	BOX	31 min
Oct 31, 3:11 AM EDT	Special Weather Statement	BOX	64 min
Oct 31, 3:21 AM EDT	Areal Flood Warning	BOX	96 min
Nov 5, 3:45 AM EDT	Coastal Flood Statement	BOX	11 hr
Nov 5, 4:03 PM EDT	Coastal Flood Statement	BOX	23 hr
Nov 6, 3:23 PM EDT	Coastal Flood Statement	BOX	24 hr
Nov 8, 4:11 AM EST	Coastal Flood Statement	BOX	11 hr
Nov 12, 3:13 AM EST	Wind Advisory	BOX	16 hr
Nov 13, 4:09 PM EST	Mesoscale Discussion	SPC	2 hr
Nov 13, 5:12 PM EST	Severe Thunderstorm Warning	BOX	44 min
Nov 13, 5:17 PM EST	Severe Thunderstorm Warning	BOX	7 min
Nov 13, 5:26 PM EST	Severe Thunderstorm Warning	BOX	32 min
Nov 13, 5:45 PM EST	Special Weather Statement	BOX	45 min
Nov 13, 5:45 PM EST	Severe Thunderstorm Warning	BOX	60 min
Nov 13, 5:55 PM EST	Severe Thunderstorm Warning	BOX	25 min
Dec 2, 9:49 PM EST	Special Weather Statement	BOX	56 min
Dec 2, 10:44 PM EST	Special Weather Statement	BOX	61 min
Dec 5, 2:58 PM EST	Wind Advisory	BOX	34 hr
Dec 6, 10:06 PM EST	Special Weather Statement	BOX	54 min
Dec 6, 10:42 PM EST	Special Weather Statement	BOX	48 min
Dec 10, 3:45 PM EST	Wind Advisory	BOX	36 hr
Dec 22, 9:18 AM EST	Dense Fog Advisory	BOX	5 hr
Dec 24, 3:39 AM EST	Winter Weather Advisory	BOX	49 hr
Dec 25, 5:44 AM EST	Mesoscale Discussion	SPC	5 hr
Dec 30, 9:25 PM EST	Dense Fog Advisory	BOX	13 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	27
Tornado Warning	1
Severe Thunderstorm Watch	5
Tornado Watch	1
Mesoscale Discussion	19
Special Weather Statement	22
Flooding
Areal Flood Warning	8
Flash Flood Warning	4
River Flood Warning	2
Flash Flood Watch	4
Flood Watch	1
Winter
Winter Storm Warning	2
Winter Storm Watch	3
Winter Weather Advisory	7
Heat
Excessive Heat Warning	1
Excessive Heat Watch	1
Heat Advisory	11
Cold
Freeze Warning	1
Freeze Watch	1
Frost Advisory	1
Wind and dust
High Wind Warning	1
High Wind Watch	1
Wind Advisory	14
Fire
Red Flag Warning	3
Fog and smoke
Dense Fog Advisory	11
Tropical
Storm Surge Warning	1
Tropical Storm Warning	2
Hurricane Watch	1
Storm Surge Watch	1
Tropical Storm Watch	1
Coast and beach
Coastal Flood Warning	1
Coastal Flood Watch	1
Coastal Flood Advisory	9
High Surf Advisory	1
Coastal Flood Statement	14
Rip Current Statement	7

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.