Alert archive / Massachusetts / Norfolk County

Weather alerts in Norfolk County, Massachusetts, 2009

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

Norfolk County and its neighbors

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

Alerts: 165
Warnings: 42
Watches: 22
Advisories: 81
Busiest month: July44 alerts
Busiest day: July 31, 20099 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 Norfolk County in 2009 had a tornado report inside them.

Norfolk County, 2009

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	1	0	100%	0
Severe thunderstorm warnings	23	14	39%	17	47%	21 min
Flash flood warnings	2	0	100%	0

Each office's whole area, 2009

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Boston/Norton, MA: tornado warnings	2	0	100%	2	0%
NWS Boston/Norton, MA: severe thunderstorm warnings	114	66	42%	250	78%	21 min
NWS Boston/Norton, MA: flash flood warnings	22	3	86%	13	62%	68 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
Dec 31, 10:03 PM EST	Wind Advisory	BOX	3 hr
Jan 5, 3:33 PM EST	Winter Storm Watch	BOX	24 hr
Jan 6, 4:53 AM EST	Winter Weather Advisory	BOX	32 hr
Jan 7, 12:10 AM EST	Mesoscale Discussion	SPC	4 hr
Jan 7, 6:08 AM EST	Mesoscale Discussion	SPC	3 hr
Jan 7, 9:16 AM EST	Areal Flood Advisory	BOX	8 hr
Jan 7, 4:32 PM EST	Wind Advisory	BOX	26 hr
Jan 7, 9:26 PM EST	Freezing Rain Advisory	BOX	3 hr
Jan 9, 4:25 AM EST	Winter Storm Watch	BOX	24 hr
Jan 10, 4:39 AM EST	Winter Storm Warning	BOX	30 hr
Jan 10, 11:52 AM EST	Coastal Flood Advisory	BOX	24 hr
Jan 14, 4:02 PM EST	Winter Weather Advisory	BOX	29 hr
Jan 17, 4:22 PM EST	Winter Storm Warning	BOX	22 hr
Jan 17, 4:22 PM EST	Winter Weather Advisory	BOX	22 hr
Jan 18, 4:16 PM EST	Winter Weather Advisory	BOX	14 hr
Jan 26, 3:35 PM EST	Winter Storm Watch	BOX	24 hr
Jan 27, 3:28 AM EST	Winter Storm Warning	BOX	45 hr
Jan 27, 3:51 PM EST	Winter Weather Advisory	BOX	23 hr
Jan 28, 12:24 PM EST	Mesoscale Discussion	SPC	4 hr
Feb 2, 4:07 PM EST	Winter Storm Watch	BOX	13 hr
Feb 3, 4:40 AM EST	Winter Weather Advisory	BOX	22 hr
Feb 11, 4:40 AM EST	High Wind Watch	BOX	11 hr
Feb 11, 3:48 PM EST	Wind Advisory	BOX	36 hr
Feb 19, 4:55 AM EST	Dense Fog Advisory	BOX	3 hr
Feb 22, 5:11 PM EST	Wind Advisory	BOX	23 hr
Feb 27, 3:34 AM EST	Wind Advisory	BOX	16 hr
Feb 28, 5:07 AM EST	Winter Storm Watch	BOX	36 hr
Mar 1, 4:27 AM EST	Winter Storm Warning	BOX	35 hr
Mar 1, 4:27 AM EST	Winter Weather Advisory	BOX	12 hr
Mar 1, 4:43 PM EST	Winter Weather Advisory	BOX	26 hr
Mar 2, 12:41 AM EST	Mesoscale Discussion	SPC	4 hr
Mar 2, 6:38 AM EST	Mesoscale Discussion	SPC	4 hr
Mar 8, 3:59 PM EDT	Winter Weather Advisory	BOX	26 hr
Apr 2, 8:40 PM EDT	Dense Fog Advisory	BOX	12 hr
Apr 3, 5:39 PM EDT	Dense Fog Advisory	BOX	6 hr
Apr 4, 3:09 PM EDT	Wind Advisory	BOX	3 hr
Apr 6, 4:35 AM EDT	Wind Advisory	BOX	17 hr
Apr 6, 2:28 PM EDT	Areal Flood Advisory	BOX	3 hr
Apr 16, 4:50 PM EDT	Fire Weather Watch	BOX	11 hr
Apr 17, 4:11 AM EDT	Red Flag Warning	BOX	16 hr
Apr 20, 4:19 AM EDT	Wind Advisory	BOX	24 hr
Apr 27, 4:40 PM EDT	Fire Weather Watch	BOX	12 hr
Apr 28, 4:26 AM EDT	Red Flag Warning	BOX	17 hr
May 13, 4:21 PM EDT	Wind Advisory	BOX	27 hr
May 15, 9:54 PM EDT	Dense Fog Advisory	BOX	10 hr
May 18, 4:18 AM EDT	Frost Advisory	BOX	27 hr
May 20, 4:12 PM EDT	Fire Weather Watch	BOX	12 hr
May 21, 3:47 AM EDT	Red Flag Warning	BOX	16 hr
May 24, 1:55 PM EDT	Severe Thunderstorm Warning	BOX	24 min
May 24, 3:05 PM EDT	Severe Thunderstorm Warning	BOX	40 min
May 24, 4:28 PM EDT	Severe Thunderstorm Warning	BOX	32 min
May 24, 4:46 PM EDT	Severe Thunderstorm Warning	BOX	44 min
May 24, 5:14 PM EDT	Severe Thunderstorm Warning	BOX	31 min
Jun 19, 4:35 PM EDT	Flood Watch	BOX	36 hr
Jun 21, 4:41 AM EDT	Wind Advisory	BOX	41 hr
Jun 21, 9:56 AM EDT	Coastal Flood Statement	BOX	6 hr
Jun 21, 4:15 PM EDT	Coastal Flood Advisory	BOX	35 hr
Jun 21, 4:15 PM EDT	High Surf Advisory	BOX	50 hr
Jun 27, 3:45 PM EDT	Areal Flood Advisory	BOX	3 hr
Jun 27, 3:51 PM EDT	Severe Thunderstorm Warning	BOX	39 min
Jun 27, 4:13 PM EDT	Areal Flood Advisory	BOX	3 hr
Jun 27, 4:16 PM EDT	Severe Thunderstorm Warning	BOX	44 min
Jun 27, 4:24 PM EDT	Flash Flood Warning	BOX	2 hr
Jun 27, 4:38 PM EDT	Mesoscale Discussion	SPC	67 min
Jun 27, 6:45 PM EDT	Areal Flood Advisory	BOX	3 hr
Jul 1, 4:54 AM EDT	Flash Flood Watch	BOX	42 hr
Jul 1, 10:57 AM EDT	Areal Flood Advisory	BOX	3 hr
Jul 1, 2:09 PM EDT	Areal Flood Warning	BOX	3 hr
Jul 2, 4:04 AM EDT	Severe Thunderstorm Warning	BOX	26 min
Jul 2, 6:57 AM EDT	Areal Flood Advisory	BOX	3 hr
Jul 2, 7:50 AM EDT	Areal Flood Advisory	BOX	3 hr
Jul 2, 8:18 AM EDT	Flash Flood Warning	BOX	4 hr
Jul 2, 11:02 AM EDT	Areal Flood Advisory	BOX	2 hr
Jul 2, 12:18 PM EDT	Areal Flood Advisory	BOX	3 hr
Jul 2, 3:20 PM EDT	Mesoscale Discussion	SPC	55 min
Jul 3, 4:08 AM EDT	Flash Flood Watch	BOX	16 hr
Jul 3, 3:44 PM EDT	Severe Thunderstorm Warning	BOX	46 min
Jul 7, 11:05 AM EDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 7, 1:54 PM EDT	Severe Thunderstorm Warning	BOX	50 min
Jul 7, 2:00 PM EDT	Mesoscale Discussion	SPC	90 min
Jul 7, 2:39 PM EDT	Severe Thunderstorm Warning	BOX	66 min
Jul 7, 3:46 PM EDT	Severe Thunderstorm Warning	BOX	44 min
Jul 7, 4:41 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 8, 3:09 PM EDT	Severe Thunderstorm Warning	BOX	51 min
Jul 8, 3:11 PM EDT	Tornado Warning	BOX	34 min
Jul 8, 3:33 PM EDT	Areal Flood Advisory	BOX	115 min
Jul 8, 3:52 PM EDT	Severe Thunderstorm Warning	BOX	38 min
Jul 8, 4:27 PM EDT	Severe Thunderstorm Warning	BOX	36 min
Jul 8, 4:49 PM EDT	Severe Thunderstorm Warning	BOX	41 min
Jul 21, 9:28 AM EDT	Areal Flood Advisory	BOX	6 hr
Jul 23, 4:48 AM EDT	Coastal Flood Statement	BOX	11 hr
Jul 23, 2:54 PM EDT	Flood Watch	BOX	19 hr
Jul 23, 4:16 PM EDT	Coastal Flood Advisory	BOX	11 hr
Jul 24, 1:10 AM EDT	Areal Flood Advisory	BOX	4 hr
Jul 26, 4:38 AM EDT	Flash Flood Watch	BOX	24 hr
Jul 26, 1:13 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 26, 3:14 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 26, 3:51 PM EDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 26, 6:37 PM EDT	Mesoscale Discussion	SPC	113 min
Jul 27, 12:38 AM EDT	Severe Thunderstorm Warning	BOX	22 min
Jul 31, 11:55 AM EDT	Areal Flood Advisory	BOX	3 hr
Jul 31, 2:32 PM EDT	Mesoscale Discussion	SPC	88 min
Jul 31, 3:57 PM EDT	Areal Flood Advisory	BOX	3 hr
Jul 31, 4:33 PM EDT	Severe Thunderstorm Warning	BOX	42 min
Jul 31, 4:52 PM EDT	Severe Thunderstorm Warning	BOX	23 min
Jul 31, 4:58 PM EDT	Areal Flood Advisory	BOX	2 hr
Jul 31, 5:22 PM EDT	Severe Thunderstorm Warning	BOX	23 min
Jul 31, 5:32 PM EDT	Severe Thunderstorm Warning	BOX	58 min
Jul 31, 5:40 PM EDT	Areal Flood Advisory	BOX	80 min
Aug 5, 2:16 PM EDT	Mesoscale Discussion	SPC	59 min
Aug 5, 4:08 PM EDT	Severe Thunderstorm Warning	BOX	42 min
Aug 10, 4:13 AM EDT	Heat Advisory	BOX	11 hr
Aug 20, 2:29 PM EDT	Areal Flood Advisory	BOX	91 min
Aug 20, 3:21 PM EDT	Severe Thunderstorm Warning	BOX	24 min
Aug 21, 4:23 PM EDT	High Surf Advisory	BOX	72 hr
Aug 21, 5:55 PM EDT	Mesoscale Discussion	SPC	80 min
Aug 28, 4:29 PM EDT	Flood Watch	BOX	26 hr
Aug 29, 1:20 PM EDT	Areal Flood Advisory	BOX	3 hr
Aug 29, 4:18 PM EDT	Areal Flood Advisory	BOX	3 hr
Sep 12, 9:07 AM EDT	Areal Flood Advisory	BOX	3 hr
Sep 12, 10:56 PM EDT	Areal Flood Advisory	BOX	64 min
Sep 12, 11:10 PM EDT	Areal Flood Advisory	BOX	65 min
Sep 19, 2:49 AM EDT	Frost Advisory	BOX	29 hr
Oct 3, 4:51 AM EDT	Areal Flood Advisory	BOX	5 hr
Oct 3, 6:55 AM EDT	Areal Flood Advisory	BOX	3 hr
Oct 6, 3:28 PM EDT	Wind Advisory	BOX	36 hr
Oct 11, 3:05 AM EDT	Frost Advisory	BOX	29 hr
Oct 14, 4:09 AM EDT	Frost Advisory	BOX	28 hr
Oct 14, 4:09 AM EDT	Freeze Warning	BOX	28 hr
Oct 14, 4:43 PM EDT	Coastal Flood Statement	BOX	36 hr
Oct 15, 4:43 AM EDT	Wind Advisory	BOX	29 hr
Oct 15, 4:58 AM EDT	Coastal Flood Watch	BOX	23 hr
Oct 16, 4:18 AM EDT	Coastal Flood Advisory	BOX	7 hr
Oct 16, 6:30 PM EDT	Coastal Flood Statement	BOX	10 hr
Oct 17, 4:42 AM EDT	Coastal Flood Watch	BOX	11 hr
Oct 17, 3:59 PM EDT	Coastal Flood Warning	BOX	24 hr
Oct 17, 4:15 PM EDT	Wind Advisory	BOX	36 hr
Oct 18, 4:01 PM EDT	Coastal Flood Advisory	BOX	11 hr
Oct 19, 11:42 PM EDT	Freeze Warning	BOX	7 hr
Oct 24, 9:19 PM EDT	Wind Advisory	BOX	5 hr
Oct 31, 3:31 AM EDT	Wind Advisory	BOX	16 hr
Nov 13, 3:52 PM EST	Coastal Flood Advisory	BOX	19 hr
Nov 15, 7:09 PM EST	Dense Fog Advisory	BOX	6 hr
Nov 27, 4:10 AM EST	Wind Advisory	BOX	34 hr
Nov 28, 8:40 AM EST	High Wind Warning	BOX	6 hr
Nov 28, 2:26 PM EST	Wind Advisory	BOX	2 hr
Dec 2, 4:16 AM EST	High Wind Watch	BOX	12 hr
Dec 2, 4:25 PM EST	High Wind Warning	BOX	18 hr
Dec 2, 4:25 PM EST	Wind Advisory	BOX	18 hr
Dec 3, 5:38 AM EST	Areal Flood Advisory	BOX	112 min
Dec 5, 4:36 AM EST	Winter Weather Advisory	BOX	22 hr
Dec 5, 4:39 AM EST	Wind Advisory	BOX	27 hr
Dec 8, 3:39 PM EST	Coastal Flood Advisory	BOX	27 hr
Dec 8, 3:59 PM EST	Winter Storm Warning	BOX	21 hr
Dec 8, 3:59 PM EST	Winter Weather Advisory	BOX	19 hr
Dec 8, 4:11 PM EST	Wind Advisory	BOX	23 hr
Dec 18, 3:20 PM EST	Blizzard Watch	BOX	13 hr
Dec 18, 3:20 PM EST	Winter Storm Watch	BOX	13 hr
Dec 19, 4:23 AM EST	Blizzard Warning	BOX	33 hr
Dec 19, 4:23 AM EST	Winter Storm Warning	BOX	32 hr
Dec 20, 12:32 AM EST	Mesoscale Discussion	SPC	4 hr
Dec 25, 4:25 PM EST	Freezing Rain Advisory	BOX	3 hr
Dec 25, 7:09 PM EST	Winter Weather Advisory	BOX	27 hr
Dec 29, 4:04 AM EST	Wind Advisory	BOX	21 hr
Dec 31, 4:03 AM EST	Winter Weather Advisory	BOX	11 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	23
Tornado Warning	1
Severe Thunderstorm Watch	2
Mesoscale Discussion	16
Flooding
Areal Flood Warning	1
Flash Flood Warning	2
Flash Flood Watch	3
Flood Watch	3
Areal Flood Advisory	26
Winter
Blizzard Warning	1
Winter Storm Warning	6
Blizzard Watch	1
Winter Storm Watch	6
Freezing Rain Advisory	2
Winter Weather Advisory	13
Heat
Heat Advisory	1
Cold
Freeze Warning	2
Frost Advisory	4
Wind and dust
High Wind Warning	2
High Wind Watch	2
Wind Advisory	21
Fire
Red Flag Warning	3
Fire Weather Watch	3
Fog and smoke
Dense Fog Advisory	5
Coast and beach
Coastal Flood Warning	1
Coastal Flood Watch	2
Coastal Flood Advisory	7
High Surf Advisory	2
Coastal Flood Statement	4

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.