Alert archive / Massachusetts / Nantucket County

Weather alerts in Nantucket County, Massachusetts, 2020

118 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Nantucket County and its neighbors

Each county as a circle sized by its count in 2020. Tap one for its archive.

Alerts: 118
Warnings: 18
Watches: 15
Advisories: 66
Busiest month: April18 alerts
Busiest day: April 2, 20204 alerts

Over time

By month

Warning verification

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

Nantucket County, 2020

	Warnings	With a report	False alarm ratio	Reports	Inside a warning
Tornado warnings	0			0
Severe thunderstorm warnings	3	1	67%	1	0%
Flash flood warnings	0			0

Each office's whole area, 2020

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Boston/Norton, MA: tornado warnings	8	1	88%	2	50%	5 min
NWS Boston/Norton, MA: severe thunderstorm warnings	152	115	24%	525	85%	26 min
NWS Boston/Norton, MA: flash flood warnings	16	2	88%	5	60%	16 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 7, 11:31 AM EST	Winter Weather Advisory	BOX	17 hr
Jan 7, 3:58 PM EST	Wind Advisory	BOX	31 hr
Jan 11, 1:08 PM EST	Wind Advisory	BOX	27 hr
Jan 15, 3:47 PM EST	Wind Advisory	BOX	36 hr
Feb 6, 3:23 PM EST	High Wind Warning	BOX	30 hr
Feb 7, 9:36 PM EST	Wind Advisory	BOX	3 hr
Feb 26, 4:24 PM EST	Wind Advisory	BOX	32 hr
Mar 5, 4:33 AM EST	High Wind Watch	BOX	24 hr
Mar 6, 4:08 AM EST	High Wind Warning	BOX	30 hr
Mar 6, 4:23 AM EST	Winter Weather Advisory	BOX	28 hr
Mar 6, 4:26 AM EST	Coastal Flood Advisory	BOX	31 hr
Mar 7, 9:46 AM EST	Wind Advisory	BOX	4 hr
Mar 23, 4:53 PM EDT	Wind Advisory	BOX	11 hr
Apr 1, 3:31 PM EDT	High Wind Watch	BOX	12 hr
Apr 1, 3:33 PM EDT	Coastal Flood Watch	BOX	12 hr
Apr 1, 3:33 PM EDT	Coastal Flood Advisory	BOX	18 hr
Apr 2, 3:11 AM EDT	High Wind Warning	BOX	40 hr
Apr 2, 3:11 AM EDT	Wind Advisory	BOX	49 hr
Apr 2, 3:18 AM EDT	Coastal Flood Warning	BOX	33 hr
Apr 2, 3:51 PM EDT	Coastal Flood Advisory	BOX	6 hr
Apr 3, 3:32 PM EDT	Coastal Flood Advisory	BOX	6 hr
Apr 4, 3:50 AM EDT	Coastal Flood Advisory	BOX	7 hr
Apr 9, 4:10 AM EDT	Wind Advisory	BOX	18 hr
Apr 9, 2:56 PM EDT	Special Weather Statement	BOX	64 min
Apr 9, 4:24 PM EDT	Severe Thunderstorm Warning	BOX	66 min
Apr 10, 3:54 AM EDT	Wind Advisory	BOX	16 hr
Apr 11, 3:29 PM EDT	High Wind Watch	BOX	25 hr
Apr 12, 4:07 PM EDT	High Wind Warning	BOX	28 hr
Apr 20, 3:36 PM EDT	Frost Advisory	BOX	16 hr
Apr 20, 3:36 PM EDT	Wind Advisory	BOX	28 hr
Apr 27, 4:29 PM EDT	Coastal Flood Statement	BOX	14 hr
May 6, 3:57 AM EDT	Coastal Flood Statement	BOX	22 hr
May 6, 3:41 PM EDT	Coastal Flood Advisory	BOX	35 hr
May 8, 3:26 AM EDT	Coastal Flood Statement	BOX	10 hr
May 8, 1:45 PM EDT	Coastal Flood Advisory	BOX	13 hr
May 8, 3:42 PM EDT	Wind Advisory	BOX	34 hr
May 23, 10:35 AM EDT	Areal Flood Warning	BOX	6 hr
May 25, 9:16 PM EDT	Dense Fog Advisory	BOX	11 hr
May 26, 2:21 PM EDT	Dense Fog Advisory	BOX	18 hr
May 27, 4:07 PM EDT	Dense Fog Advisory	BOX	15 hr
May 28, 10:13 PM EDT	Dense Fog Advisory	BOX	14 hr
Jun 4, 3:30 AM EDT	Rip Current Statement	BOX	15 hr
Jun 5, 9:39 AM EDT	Special Weather Statement	BOX	36 min
Jun 10, 4:10 PM EDT	Dense Fog Advisory	BOX	12 hr
Jun 11, 3:54 AM EDT	High Surf Advisory	BOX	16 hr
Jun 23, 7:10 PM EDT	Dense Fog Advisory	BOX	8 hr
Jun 28, 5:28 PM EDT	Special Weather Statement	BOX	62 min
Jun 29, 9:24 AM EDT	Special Weather Statement	BOX	36 min
Jun 29, 9:28 AM EDT	Severe Thunderstorm Warning	BOX	32 min
Jul 9, 4:06 PM EDT	Flash Flood Watch	BOX	29 hr
Jul 11, 3:19 AM EDT	High Surf Advisory	BOX	15 hr
Jul 11, 7:02 PM EDT	High Surf Advisory	BOX	25 hr
Jul 12, 7:40 PM EDT	High Surf Advisory	BOX	48 hr
Jul 18, 4:22 AM EDT	Dense Fog Advisory	BOX	4 hr
Jul 18, 11:05 PM EDT	Dense Fog Advisory	BOX	11 hr
Jul 20, 1:19 AM EDT	Dense Fog Advisory	BOX	9 hr
Jul 20, 10:03 AM EDT	Dense Fog Advisory	BOX	57 min
Jul 20, 3:49 PM EDT	Dense Fog Advisory	BOX	3 hr
Aug 3, 5:18 AM EDT	Tropical Storm Watch	BOX	8 hr
Aug 3, 11:11 AM EDT	Tropical Storm Warning	BOX	36 hr
Aug 4, 12:43 PM EDT	Tornado Watch	SPC	6 hr
Aug 4, 11:06 PM EDT	High Surf Advisory	BOX	19 hr
Aug 14, 3:24 AM EDT	High Surf Advisory	BOX	41 hr
Aug 15, 4:21 PM EDT	High Surf Advisory	BOX	28 hr
Aug 16, 4:13 PM EDT	High Surf Advisory	BOX	28 hr
Aug 18, 5:52 AM EDT	Special Weather Statement	BOX	53 min
Aug 18, 6:42 AM EDT	Special Weather Statement	BOX	33 min
Aug 25, 3:12 PM EDT	Severe Thunderstorm Watch	SPC	5 hr
Sep 8, 7:10 PM EDT	Dense Fog Advisory	BOX	13 hr
Sep 10, 1:42 AM EDT	Dense Fog Advisory	BOX	8 hr
Sep 13, 3:55 PM EDT	High Surf Advisory	BOX	52 hr
Sep 18, 3:12 AM EDT	High Surf Advisory	BOX	17 hr
Sep 19, 3:58 AM EDT	Coastal Flood Statement	BOX	11 hr
Sep 19, 3:58 AM EDT	High Surf Advisory	BOX	5 days
Sep 20, 3:37 PM EDT	Coastal Flood Statement	BOX	26 hr
Sep 21, 3:16 AM EDT	Wind Advisory	BOX	42 hr
Sep 21, 3:29 AM EDT	Coastal Flood Advisory	BOX	40 hr
Sep 21, 3:48 PM EDT	Fire Weather Watch	BOX	11 hr
Sep 22, 3:05 AM EDT	High Wind Warning	BOX	16 hr
Sep 22, 3:10 AM EDT	Red Flag Warning	BOX	16 hr
Sep 28, 9:06 PM EDT	Dense Fog Advisory	BOX	13 hr
Sep 29, 4:01 AM EDT	Wind Advisory	BOX	33 hr
Oct 6, 3:52 AM EDT	Wind Advisory	BOX	12 hr
Oct 6, 3:22 PM EDT	High Wind Warning	BOX	30 hr
Oct 7, 5:20 PM EDT	Mesoscale Discussion	SPC	85 min
Oct 9, 3:58 PM EDT	Wind Advisory	BOX	27 hr
Oct 9, 4:14 PM EDT	Fire Weather Watch	BOX	12 hr
Oct 10, 3:49 AM EDT	Red Flag Warning	BOX	16 hr
Oct 17, 4:07 PM EDT	Coastal Flood Statement	BOX	24 hr
Oct 18, 4:04 PM EDT	Coastal Flood Statement	BOX	23 hr
Oct 20, 11:17 PM EDT	Dense Fog Advisory	BOX	13 hr
Oct 21, 6:16 PM EDT	Dense Fog Advisory	BOX	15 hr
Oct 23, 2:35 AM EDT	Dense Fog Advisory	BOX	4 hr
Oct 29, 3:11 AM EDT	Wind Advisory	BOX	33 hr
Nov 1, 3:07 PM EST	Wind Advisory	BOX	43 hr
Nov 10, 2:57 AM EST	Dense Fog Advisory	BOX	6 hr
Nov 14, 3:39 PM EST	Wind Advisory	BOX	33 hr
Nov 15, 3:40 AM EST	Coastal Flood Advisory	BOX	9 hr
Nov 15, 7:32 PM EST	Severe Thunderstorm Watch	SPC	5 hr
Nov 16, 3:54 AM EST	Coastal Flood Statement	BOX	11 hr
Nov 23, 11:54 AM EST	Severe Thunderstorm Warning	BOX	17 min
Nov 29, 2:42 AM EST	High Wind Watch	BOX	25 hr
Nov 30, 3:29 AM EST	High Wind Warning	BOX	19 hr
Nov 30, 3:03 PM EST	Coastal Flood Statement	BOX	7 hr
Nov 30, 10:15 PM EST	Wind Advisory	BOX	6 hr
Dec 4, 3:44 AM EST	High Wind Watch	BOX	11 hr
Dec 4, 3:07 PM EST	High Wind Warning	BOX	33 hr
Dec 5, 11:58 PM EST	Wind Advisory	BOX	5 hr
Dec 13, 3:15 PM EST	Coastal Flood Statement	BOX	22 hr
Dec 15, 3:26 PM EST	Coastal Flood Advisory	BOX	49 hr
Dec 16, 9:31 AM EST	High Wind Warning	BOX	24 hr
Dec 17, 11:47 PM EST	Winter Weather Advisory	BOX	12 hr
Dec 18, 12:39 PM EST	Coastal Flood Statement	BOX	4 hr
Dec 21, 12:21 AM EST	Dense Fog Advisory	BOX	7 hr
Dec 22, 3:28 PM EST	High Wind Watch	BOX	23 hr
Dec 23, 2:05 PM EST	Flood Watch	BOX	51 hr
Dec 23, 2:30 PM EST	High Wind Warning	BOX	45 hr
Dec 25, 11:38 AM EST	Wind Advisory	BOX	80 min

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
Severe Thunderstorm Watch	2
Tornado Watch	1
Mesoscale Discussion	1
Special Weather Statement	6
Flooding
Areal Flood Warning	1
Flash Flood Watch	1
Flood Watch	1
Winter
Winter Weather Advisory	3
Cold
Frost Advisory	1
Wind and dust
High Wind Warning	10
High Wind Watch	6
Wind Advisory	22
Fire
Red Flag Warning	2
Fire Weather Watch	2
Fog and smoke
Dense Fog Advisory	19
Tropical
Tropical Storm Warning	1
Tropical Storm Watch	1
Coast and beach
Coastal Flood Warning	1
Coastal Flood Watch	1
Coastal Flood Advisory	10
High Surf Advisory	11
Coastal Flood Statement	11
Rip Current Statement	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 2019 2021

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.