Alert archive / Massachusetts / Norfolk County

Weather alerts in Norfolk County, Massachusetts, 2018

261 weather alerts in 2018, 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 2018. Tap one for its archive.

Alerts
261
Warnings
62
Watches
39
Advisories
109
Busiest month
March45 alerts
Busiest day
July 17, 201812 alerts

Over time

By month

Warning verification

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

1 of 2 tornado warnings covering Norfolk County in 2018 had a tornado report inside them.

Norfolk County, 2018

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings2150%0
Severe thunderstorm warnings13654%1155%22 min
Flash flood warnings6350%12100%94 min

Each office's whole area, 2018

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Boston/Norton, MA: tornado warnings16475%1242%11 min
NWS Boston/Norton, MA: severe thunderstorm warnings914452%23359%24 min
NWS Boston/Norton, MA: flash flood warnings361072%11494%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.

IssuedProductOfficeLasted
Jan 2, 3:09 AM ESTWinter Storm WatchBOX25 hr
Jan 2, 2:57 PM ESTCoastal Flood WatchBOX17 hr
Jan 2, 3:50 PM ESTHigh Wind WatchBOX12 hr
Jan 3, 3:50 AM ESTBlizzard WarningBOX39 hr
Jan 3, 3:50 AM ESTWinter Storm WarningBOX39 hr
Jan 3, 8:18 AM ESTCoastal Flood WarningBOX32 hr
Jan 4, 3:46 AM ESTWind Chill WatchBOX24 hr
Jan 4, 6:06 AM ESTMesoscale DiscussionSPC6 hr
Jan 4, 4:59 PM ESTCoastal Flood StatementBOX23 hr
Jan 4, 7:14 PM ESTWind AdvisoryBOX5 hr
Jan 5, 4:02 AM ESTWind Chill AdvisoryBOX54 hr
Jan 5, 8:22 AM ESTWind AdvisoryBOX14 hr
Jan 10, 3:17 PM ESTFlood WatchBOX70 hr
Jan 12, 2:58 AM ESTWind AdvisoryBOX30 hr
Jan 12, 3:35 AM ESTWinter Weather AdvisoryBOX33 hr
Jan 12, 7:30 PM ESTAreal Flood WarningBOX6 hr
Jan 13, 1:06 AM ESTAreal Flood WarningBOX6 hr
Jan 13, 7:02 AM ESTAreal Flood WarningBOX4 hr
Jan 14, 3:09 PM ESTWinter Weather AdvisoryBOX31 hr
Jan 15, 3:46 AM ESTWinter Storm WatchBOX24 hr
Jan 15, 10:13 PM ESTWinter Weather AdvisoryBOX78 min
Jan 16, 3:56 AM ESTWinter Storm WarningBOX35 hr
Jan 16, 3:56 AM ESTWinter Weather AdvisoryBOX35 hr
Jan 22, 1:11 PM ESTDense Fog AdvisoryBOX22 hr
Jan 22, 2:08 PM ESTWind AdvisoryBOX28 hr
Jan 28, 4:02 PM ESTWinter Weather AdvisoryBOX45 hr
Jan 29, 3:36 AM ESTWind AdvisoryBOX30 hr
Jan 29, 3:38 AM ESTCoastal Flood AdvisoryBOX32 hr
Jan 29, 9:23 PM ESTCoastal Flood WarningBOX15 hr
Feb 1, 9:22 AM ESTCoastal Flood StatementBOX4 hr
Feb 1, 3:32 PM ESTWinter Weather AdvisoryBOX17 hr
Feb 6, 4:17 PM ESTWinter Weather AdvisoryBOX30 hr
Feb 10, 2:15 PM ESTFlood WatchBOX32 hr
Feb 16, 3:30 AM ESTWinter Storm WatchBOX34 hr
Feb 17, 3:30 AM ESTWinter Storm WarningBOX27 hr
Feb 17, 3:30 AM ESTWinter Weather AdvisoryBOX27 hr
Feb 28, 3:55 AM ESTCoastal Flood WatchBOX32 hr
Feb 28, 3:27 PM ESTFlood WatchBOX57 hr
Feb 28, 3:28 PM ESTHigh Wind WatchBOX24 hr
Mar 1, 3:27 AM ESTHigh Wind WarningBOX52 hr
Mar 1, 11:37 AM ESTCoastal Flood WarningBOX63 hr
Mar 1, 3:38 PM ESTWind AdvisoryBOX60 hr
Mar 2, 4:06 AM ESTWinter Weather AdvisoryBOX18 hr
Mar 2, 1:27 PM ESTAreal Flood WarningBOX12 hr
Mar 3, 5:05 AM ESTAreal Flood WarningBOX3 hr
Mar 3, 7:14 AM ESTAreal Flood WarningBOX8 hr
Mar 3, 4:27 PM ESTCoastal Flood AdvisoryBOX11 hr
Mar 4, 4:10 AM ESTCoastal Flood AdvisoryBOX11 hr
Mar 4, 8:55 AM ESTCoastal Flood WarningBOX6 hr
Mar 4, 2:25 PM ESTWind AdvisoryBOX31 hr
Mar 4, 3:13 PM ESTCoastal Flood AdvisoryBOX12 hr
Mar 5, 3:39 AM ESTWinter Storm WatchBOX35 hr
Mar 5, 3:42 AM ESTCoastal Flood AdvisoryBOX11 hr
Mar 5, 3:58 PM ESTCoastal Flood AdvisoryBOX13 hr
Mar 6, 3:48 AM ESTWinter Storm WarningBOX57 hr
Mar 6, 12:22 PM ESTFlood WatchBOX25 hr
Mar 6, 2:26 PM ESTWinter Weather AdvisoryBOX44 hr
Mar 6, 2:33 PM ESTHigh Wind WarningBOX37 hr
Mar 6, 2:33 PM ESTWind AdvisoryBOX37 hr
Mar 6, 2:40 PM ESTCoastal Flood WarningBOX39 hr
Mar 6, 2:40 PM ESTCoastal Flood AdvisoryBOX39 hr
Mar 7, 1:25 PM ESTMesoscale DiscussionSPC6 hr
Mar 7, 9:25 PM ESTWind AdvisoryBOX7 hr
Mar 8, 1:01 AM ESTHigh Wind WarningBOX3 hr
Mar 9, 8:26 AM ESTSpecial Weather StatementBOX3 hr
Mar 11, 3:51 AM EDTWinter Storm WatchBOX24 hr
Mar 11, 3:05 PM EDTHigh Wind WatchBOX21 hr
Mar 12, 3:46 AM EDTWinter Storm WarningBOX46 hr
Mar 12, 9:32 AM EDTCoastal Flood WarningBOX26 hr
Mar 12, 9:32 AM EDTCoastal Flood AdvisoryBOX26 hr
Mar 12, 11:59 AM EDTBlizzard WarningBOX32 hr
Mar 13, 5:47 AM EDTSpecial Weather StatementBOX58 min
Mar 13, 6:48 AM EDTSpecial Weather StatementBOX87 min
Mar 13, 7:08 AM EDTMesoscale DiscussionSPC6 hr
Mar 13, 1:42 PM EDTMesoscale DiscussionSPC3 hr
Mar 19, 3:18 PM EDTCoastal Flood WatchBOX47 hr
Mar 19, 3:27 PM EDTWinter Storm WatchBOX36 hr
Mar 20, 4:02 AM EDTWinter Storm WarningBOX42 hr
Mar 20, 4:05 AM EDTHigh Wind WatchBOX11 hr
Mar 20, 2:48 PM EDTWinter Weather AdvisoryBOX38 hr
Mar 20, 2:53 PM EDTWind AdvisoryBOX43 hr
Mar 21, 3:56 AM EDTCoastal Flood AdvisoryBOX26 hr
Mar 21, 8:57 PM EDTMesoscale DiscussionSPC6 hr
Mar 30, 2:07 AM EDTDense Fog AdvisoryBOX8 hr
Apr 3, 3:00 PM EDTWind AdvisoryBOX37 hr
Apr 3, 7:10 PM EDTDense Fog AdvisoryBOX21 hr
Apr 11, 2:23 AM EDTDense Fog AdvisoryBOX6 hr
Apr 13, 3:02 PM EDTWinter Weather AdvisoryBOX67 hr
Apr 15, 3:26 PM EDTCoastal Flood AdvisoryBOX23 hr
Apr 16, 9:51 AM EDTWind AdvisoryBOX10 hr
Apr 16, 5:14 PM EDTSpecial Weather StatementBOX46 min
Apr 16, 6:35 PM EDTRiver Flood WarningBOX7 hr
May 4, 3:38 AM EDTWind AdvisoryBOX27 hr
May 4, 5:52 PM EDTMesoscale DiscussionSPC83 min
May 8, 1:56 AM EDTDense Fog AdvisoryBOX8 hr
May 8, 3:36 PM EDTDense Fog AdvisoryBOX18 hr
May 9, 3:50 PM EDTDense Fog AdvisoryBOX12 hr
May 15, 1:58 PM EDTMesoscale DiscussionSPC2 hr
May 15, 2:26 PM EDTSevere Thunderstorm WatchSPC5 hr
May 15, 5:27 PM EDTSpecial Weather StatementBOX48 min
May 17, 3:59 PM EDTCoastal Flood StatementBOX36 hr
May 19, 7:27 PM EDTDense Fog AdvisoryBOX7 hr
May 23, 8:43 PM EDTSpecial Weather StatementBOX32 min
May 23, 9:12 PM EDTSpecial Weather StatementBOX33 min
May 31, 2:23 AM EDTDense Fog AdvisoryBOX9 hr
Jun 14, 3:51 AM EDTCoastal Flood StatementBOX10 hr
Jun 14, 1:37 PM EDTCoastal Flood AdvisoryBOX13 hr
Jun 15, 4:03 AM EDTCoastal Flood AdvisoryBOX24 hr
Jun 17, 4:51 PM EDTHeat AdvisoryBOX25 hr
Jun 18, 5:55 PM EDTMesoscale DiscussionSPC2 hr
Jun 18, 7:23 PM EDTSevere Thunderstorm WarningBOX29 min
Jun 28, 10:03 AM EDTAreal Flood AdvisoryBOX117 min
Jun 30, 4:16 PM EDTExcessive Heat WarningBOX28 hr
Jun 30, 4:16 PM EDTHeat AdvisoryBOX28 hr
Jul 1, 3:30 PM EDTHeat AdvisoryBOX4 days
Jul 3, 4:04 AM EDTDense Fog AdvisoryBOX5 hr
Jul 5, 3:30 PM EDTFlash Flood WatchBOX24 hr
Jul 6, 10:53 AM EDTSpecial Weather StatementBOX52 min
Jul 6, 11:44 AM EDTSpecial Weather StatementBOX61 min
Jul 12, 3:32 AM EDTCoastal Flood StatementBOX21 hr
Jul 13, 3:53 AM EDTCoastal Flood StatementBOX22 hr
Jul 14, 4:14 AM EDTCoastal Flood StatementBOX23 hr
Jul 16, 3:33 PM EDTSpecial Weather StatementBOX42 min
Jul 17, 3:58 AM EDTHeat AdvisoryBOX12 hr
Jul 17, 4:15 AM EDTFlash Flood WatchBOX15 hr
Jul 17, 10:35 AM EDTMesoscale DiscussionSPC115 min
Jul 17, 11:17 AM EDTSevere Thunderstorm WatchSPC8 hr
Jul 17, 1:08 PM EDTFlash Flood WarningBOX112 min
Jul 17, 2:19 PM EDTMesoscale DiscussionSPC86 min
Jul 17, 3:03 PM EDTAreal Flood WarningBOX3 hr
Jul 17, 4:09 PM EDTAreal Flood WarningBOX2 hr
Jul 17, 5:06 PM EDTSevere Thunderstorm WarningBOX39 min
Jul 17, 5:08 PM EDTSpecial Weather StatementBOX52 min
Jul 17, 5:20 PM EDTFlash Flood WarningBOX60 min
Jul 17, 5:47 PM EDTSevere Thunderstorm WarningBOX43 min
Jul 25, 9:39 AM EDTFlash Flood WatchBOX18 hr
Jul 25, 2:32 PM EDTSpecial Weather StatementBOX43 min
Jul 26, 2:59 AM EDTMesoscale DiscussionSPC2 hr
Jul 26, 3:35 PM EDTSpecial Weather StatementBOX55 min
Jul 26, 4:20 PM EDTSpecial Weather StatementBOX40 min
Jul 27, 7:06 PM EDTMesoscale DiscussionSPC54 min
Aug 2, 3:28 AM EDTHeat AdvisoryBOX15 hr
Aug 2, 6:59 PM EDTSpecial Weather StatementBOX46 min
Aug 3, 3:30 AM EDTHeat AdvisoryBOX15 hr
Aug 3, 1:11 PM EDTSpecial Weather StatementBOX34 min
Aug 3, 1:47 PM EDTSpecial Weather StatementBOX43 min
Aug 3, 2:41 PM EDTFlash Flood WatchBOX25 hr
Aug 4, 10:00 AM EDTAreal Flood AdvisoryBOX2 hr
Aug 4, 10:24 AM EDTFlash Flood WarningBOX106 min
Aug 4, 10:54 AM EDTAreal Flood AdvisoryBOX2 hr
Aug 4, 11:14 AM EDTAreal Flood AdvisoryBOX3 hr
Aug 4, 11:23 AM EDTFlash Flood WarningBOX93 min
Aug 5, 4:00 AM EDTDense Fog AdvisoryBOX5 hr
Aug 5, 2:58 PM EDTHeat AdvisoryBOX53 hr
Aug 8, 3:29 AM EDTHeat AdvisoryBOX15 hr
Aug 8, 3:05 PM EDTSpecial Weather StatementBOX40 min
Aug 8, 3:14 PM EDTAreal Flood AdvisoryBOX39 min
Aug 8, 3:54 PM EDTAreal Flood AdvisoryBOX66 min
Aug 8, 8:11 PM EDTSevere Thunderstorm WarningBOX47 min
Aug 8, 8:20 PM EDTAreal Flood AdvisoryBOX115 min
Aug 8, 8:57 PM EDTAreal Flood WarningBOX2 hr
Aug 8, 9:06 PM EDTSpecial Weather StatementBOX54 min
Aug 8, 9:57 PM EDTSpecial Weather StatementBOX48 min
Aug 9, 3:25 AM EDTHeat AdvisoryBOX14 hr
Aug 10, 3:03 PM EDTCoastal Flood StatementBOX11 hr
Aug 10, 3:20 PM EDTFlash Flood WatchBOX48 hr
Aug 11, 2:44 AM EDTCoastal Flood AdvisoryBOX23 hr
Aug 11, 8:32 PM EDTAreal Flood AdvisoryBOX58 min
Aug 12, 2:51 AM EDTCoastal Flood AdvisoryBOX24 hr
Aug 12, 6:31 AM EDTAreal Flood AdvisoryBOX59 min
Aug 12, 11:07 AM EDTDense Fog AdvisoryBOX3 hr
Aug 12, 3:18 PM EDTAreal Flood AdvisoryBOX35 min
Aug 13, 3:24 AM EDTDense Fog AdvisoryBOX7 hr
Aug 14, 3:47 AM EDTDense Fog AdvisoryBOX5 hr
Aug 18, 12:11 PM EDTMesoscale DiscussionSPC2 hr
Aug 25, 4:21 AM EDTDense Fog AdvisoryBOX3 hr
Aug 27, 2:51 AM EDTExcessive Heat WatchBOX24 hr
Aug 27, 2:51 AM EDTHeat AdvisoryBOX66 hr
Aug 27, 3:20 PM EDTExcessive Heat WarningBOX54 hr
Sep 2, 2:54 PM EDTHeat AdvisoryBOX48 hr
Sep 5, 2:55 PM EDTHeat AdvisoryBOX27 hr
Sep 6, 4:23 PM EDTSevere Thunderstorm WarningBOX41 min
Sep 6, 4:43 PM EDTSevere Thunderstorm WarningBOX47 min
Sep 8, 3:52 PM EDTCoastal Flood StatementBOX8 hr
Sep 9, 4:08 AM EDTCoastal Flood AdvisoryBOX22 hr
Sep 10, 3:59 PM EDTCoastal Flood AdvisoryBOX10 hr
Sep 11, 4:42 PM EDTSpecial Weather StatementBOX48 min
Sep 11, 9:04 PM EDTDense Fog AdvisoryBOX12 hr
Sep 12, 1:13 PM EDTAreal Flood AdvisoryBOX2 hr
Sep 12, 3:10 PM EDTFlash Flood WatchBOX16 hr
Sep 13, 2:56 AM EDTAreal Flood AdvisoryBOX74 min
Sep 13, 3:39 AM EDTAreal Flood AdvisoryBOX2 hr
Sep 14, 8:13 PM EDTDense Fog AdvisoryBOX12 hr
Sep 16, 4:04 AM EDTDense Fog AdvisoryBOX4 hr
Sep 17, 3:36 AM EDTFlash Flood WatchBOX39 hr
Sep 18, 8:21 AM EDTSpecial Weather StatementBOX54 min
Sep 18, 10:17 AM EDTFlash Flood WarningBOX4 hr
Sep 18, 11:23 AM EDTFlash Flood WarningBOX4 hr
Sep 18, 2:01 PM EDTAreal Flood WarningBOX4 hr
Sep 18, 3:14 PM EDTAreal Flood WarningBOX3 hr
Sep 25, 8:32 PM EDTAreal Flood AdvisoryBOX58 min
Sep 25, 10:19 PM EDTAreal Flood WarningBOX61 min
Sep 25, 10:46 PM EDTAreal Flood AdvisoryBOX59 min
Sep 25, 11:14 PM EDTAreal Flood AdvisoryBOX2 hr
Sep 26, 1:44 AM EDTAreal Flood AdvisoryBOX2 hr
Sep 27, 3:30 PM EDTFlash Flood WatchBOX21 hr
Oct 10, 2:42 PM EDTFlash Flood WatchBOX47 hr
Oct 11, 3:14 PM EDTWind AdvisoryBOX26 hr
Oct 11, 4:38 PM EDTSpecial Weather StatementBOX22 min
Oct 11, 4:40 PM EDTSevere Thunderstorm WarningBOX35 min
Oct 11, 5:00 PM EDTSevere Thunderstorm WarningBOX30 min
Oct 13, 4:13 AM EDTFrost AdvisoryBOX29 hr
Oct 15, 8:44 PM EDTWind AdvisoryBOX9 hr
Oct 17, 2:51 AM EDTFreeze WatchBOX12 hr
Oct 17, 2:51 AM EDTWind AdvisoryBOX31 hr
Oct 17, 3:18 PM EDTFreeze WarningBOX12 hr
Oct 18, 3:42 AM EDTFrost AdvisoryBOX29 hr
Oct 18, 3:42 AM EDTFreeze WarningBOX29 hr
Oct 20, 4:12 PM EDTFreeze WatchBOX24 hr
Oct 21, 2:15 AM EDTFreeze WarningBOX31 hr
Oct 23, 3:32 PM EDTSevere Thunderstorm WarningBOX28 min
Oct 23, 3:34 PM EDTTornado WarningBOX26 min
Oct 23, 3:46 PM EDTSevere Thunderstorm WarningBOX29 min
Oct 23, 3:54 PM EDTMesoscale DiscussionSPC66 min
Oct 23, 3:59 PM EDTTornado WarningBOX31 min
Oct 23, 4:24 PM EDTSevere Thunderstorm WarningBOX23 min
Oct 23, 6:28 PM EDTSpecial Weather StatementBOX47 min
Oct 26, 3:33 AM EDTHigh Wind WatchBOX12 hr
Oct 26, 2:30 PM EDTFlash Flood WatchBOX28 hr
Oct 26, 3:23 PM EDTCoastal Flood AdvisoryBOX26 hr
Oct 26, 3:28 PM EDTHigh Wind WarningBOX31 hr
Oct 26, 3:28 PM EDTWind AdvisoryBOX31 hr
Oct 27, 9:21 AM EDTCoastal Flood WarningBOX8 hr
Oct 29, 9:55 AM EDTSevere Thunderstorm WarningBOX22 min
Oct 29, 12:38 PM EDTSpecial Weather StatementBOX22 min
Nov 2, 4:35 AM EDTHigh Wind WatchBOX10 hr
Nov 2, 2:40 PM EDTHigh Wind WarningBOX28 hr
Nov 2, 2:40 PM EDTWind AdvisoryBOX28 hr
Nov 3, 5:59 AM EDTAreal Flood AdvisoryBOX3 hr
Nov 3, 6:33 AM EDTSevere Thunderstorm WarningBOX27 min
Nov 8, 3:20 PM ESTFlood WatchBOX36 hr
Nov 9, 3:32 PM ESTWind AdvisoryBOX27 hr
Nov 13, 7:37 PM ESTRiver Flood WarningBOX8 days
Nov 14, 3:31 PM ESTWinter Weather AdvisoryBOX34 hr
Nov 15, 1:20 PM ESTWind AdvisoryBOX20 hr
Nov 15, 4:39 PM ESTMesoscale DiscussionSPC6 hr
Nov 21, 5:19 PM ESTSpecial Weather StatementBOX56 min
Nov 24, 2:32 AM ESTCoastal Flood AdvisoryBOX36 hr
Nov 26, 2:54 AM ESTCoastal Flood AdvisoryBOX26 hr
Nov 26, 3:16 AM ESTDense Fog AdvisoryBOX7 hr
Nov 26, 3:16 AM ESTHigh Wind WatchBOX12 hr
Nov 26, 3:16 AM ESTWind AdvisoryBOX36 hr
Nov 26, 3:19 PM ESTHigh Wind WarningBOX10 hr
Nov 27, 4:23 AM ESTCoastal Flood StatementBOX12 hr
Dec 2, 3:37 PM ESTDense Fog AdvisoryBOX17 hr
Dec 17, 4:02 PM ESTWind AdvisoryBOX19 hr
Dec 19, 3:17 PM ESTHigh Wind WatchBOX24 hr
Dec 19, 3:18 PM ESTFlood WatchBOX58 hr
Dec 20, 3:16 PM ESTHigh Wind WarningBOX28 hr
Dec 20, 3:16 PM ESTWind AdvisoryBOX31 hr
Dec 21, 10:19 PM ESTCoastal Flood AdvisoryBOX15 hr

By product

Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20172019

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.