Alert archive / Maryland / Baltimore County

Weather alerts in Baltimore County, Maryland, 2020

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

Baltimore County and its neighbors

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

Alerts
259
Warnings
106
Watches
42
Advisories
67
Busiest month
August58 alerts
Busiest day
April 13, 202012 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 4 tornado warnings covering Baltimore County in 2020 had a tornado report inside them.

Baltimore County, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings40100%0
Severe thunderstorm warnings463720%3678%22 min
Flash flood warnings141029%1486%60 min

Each office's whole area, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Baltimore/Washington: tornado warnings27678%1547%9 min
NWS Baltimore/Washington: severe thunderstorm warnings45631431%1,04779%23 min
NWS Baltimore/Washington: flash flood warnings663448%13090%72 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 4, 4:14 AM ESTDense Fog AdvisoryLWX7 hr
Jan 6, 1:49 PM ESTWinter Weather AdvisoryLWX29 hr
Jan 7, 12:29 PM ESTMesoscale DiscussionSPC2 hr
Jan 8, 3:40 AM ESTWind AdvisoryLWX13 hr
Jan 8, 7:33 AM ESTSnow Squall WarningLWX27 min
Jan 8, 8:03 AM ESTSnow Squall WarningLWX57 min
Jan 11, 1:13 PM ESTWind AdvisoryLWX20 hr
Jan 14, 10:41 PM ESTDense Fog AdvisoryLWX10 hr
Jan 17, 1:33 PM ESTWinter Weather AdvisoryLWX29 hr
Feb 1, 1:28 AM ESTDense Fog AdvisoryLWX9 hr
Feb 5, 3:23 PM ESTFlood WatchLWX35 hr
Feb 6, 10:04 AM ESTCoastal Flood AdvisoryLWX9 hr
Feb 6, 9:30 PM ESTWind AdvisoryLWX20 hr
Feb 7, 4:08 AM ESTDense Fog AdvisoryLWX3 hr
Feb 7, 7:56 AM ESTSevere Thunderstorm WarningLWX34 min
Feb 7, 11:22 AM ESTCoastal Flood AdvisoryLWX12 hr
Feb 26, 12:54 AM ESTDense Fog AdvisoryLWX8 hr
Mar 3, 6:50 PM ESTMesoscale DiscussionSPC2 hr
Mar 3, 10:52 PM ESTMesoscale DiscussionSPC113 min
Mar 3, 11:49 PM ESTSevere Thunderstorm WarningLWX41 min
Mar 20, 2:18 AM EDTDense Fog AdvisoryLWX7 hr
Mar 27, 3:31 AM EDTCoastal Flood AdvisoryLWX10 hr
Mar 29, 11:16 PM EDTDense Fog AdvisoryLWX5 hr
Apr 4, 4:57 PM EDTCoastal Flood AdvisoryLWX52 hr
Apr 8, 3:53 AM EDTSevere Thunderstorm WarningLWX37 min
Apr 8, 8:13 PM EDTWind AdvisoryLWX23 hr
Apr 9, 11:09 AM EDTMesoscale DiscussionSPC66 min
Apr 9, 11:51 AM EDTSevere Thunderstorm WarningLWX39 min
Apr 9, 12:01 PM EDTSevere Thunderstorm WatchSPC4 hr
Apr 9, 12:24 PM EDTSevere Thunderstorm WarningLWX66 min
Apr 9, 1:16 PM EDTSevere Thunderstorm WarningLWX18 min
Apr 9, 7:38 PM EDTWind AdvisoryLWX22 hr
Apr 9, 7:47 PM EDTFreeze WatchLWX19 hr
Apr 9, 11:21 PM EDTSevere Thunderstorm WarningLWX28 min
Apr 10, 2:28 PM EDTFreeze WarningLWX19 hr
Apr 12, 10:53 AM EDTCoastal Flood WatchLWX16 hr
Apr 12, 12:35 PM EDTWind AdvisoryLWX29 hr
Apr 13, 3:01 AM EDTCoastal Flood WarningLWX14 hr
Apr 13, 10:34 AM EDTMesoscale DiscussionSPC86 min
Apr 13, 11:09 AM EDTAreal Flood WarningLWX12 hr
Apr 13, 11:33 AM EDTTornado WatchSPC5 hr
Apr 13, 12:07 PM EDTTornado WarningLWX23 min
Apr 13, 1:20 PM EDTMesoscale DiscussionSPC85 min
Apr 13, 2:00 PM EDTSevere Thunderstorm WarningLWX45 min
Apr 13, 2:01 PM EDTSevere Thunderstorm WarningLWX44 min
Apr 13, 2:24 PM EDTSevere Thunderstorm WarningLWX51 min
Apr 13, 2:27 PM EDTSevere Thunderstorm WarningLWX48 min
Apr 13, 2:51 PM EDTAreal Flood WarningLWX4 hr
Apr 13, 5:08 PM EDTCoastal Flood AdvisoryLWX2 hr
Apr 15, 1:09 PM EDTFreeze WatchLWX24 hr
Apr 16, 1:19 PM EDTFreeze WarningLWX20 hr
Apr 18, 1:19 PM EDTFrost AdvisoryLWX20 hr
Apr 21, 4:04 AM EDTFreeze WarningLWX27 hr
Apr 21, 12:23 PM EDTMesoscale DiscussionSPC2 hr
Apr 25, 3:38 AM EDTDense Fog AdvisoryLWX3 hr
Apr 29, 4:24 AM EDTFlood WatchLWX39 hr
Apr 29, 4:31 AM EDTCoastal Flood WatchLWX35 hr
Apr 29, 7:47 AM EDTCoastal Flood AdvisoryLWX52 hr
Apr 30, 4:52 AM EDTCoastal Flood WarningLWX23 hr
Apr 30, 4:55 AM EDTCoastal Flood AdvisoryLWX23 hr
Apr 30, 9:17 AM EDTWind AdvisoryLWX5 hr
May 7, 2:16 PM EDTFreeze WatchLWX24 hr
May 7, 2:16 PM EDTFreeze WarningLWX43 hr
May 9, 3:36 AM EDTFrost AdvisoryLWX28 hr
May 9, 3:36 AM EDTFreeze WarningLWX28 hr
May 11, 3:43 AM EDTFrost AdvisoryLWX26 hr
May 12, 2:41 PM EDTFrost AdvisoryLWX18 hr
May 19, 2:58 PM EDTCoastal Flood AdvisoryLWX42 hr
May 25, 2:47 AM EDTCoastal Flood AdvisoryLWX9 hr
May 26, 8:03 AM EDTDense Fog AdvisoryLWX3 hr
May 27, 6:45 AM EDTDense Fog AdvisoryLWX3 hr
May 29, 12:27 PM EDTMesoscale DiscussionSPC63 min
May 29, 2:25 PM EDTSevere Thunderstorm WatchSPC7 hr
May 29, 3:03 PM EDTMesoscale DiscussionSPC87 min
May 29, 8:01 PM EDTMesoscale DiscussionSPC119 min
Jun 3, 11:34 AM EDTMesoscale DiscussionSPC86 min
Jun 3, 3:10 PM EDTMesoscale DiscussionSPC2 hr
Jun 4, 2:02 PM EDTMesoscale DiscussionSPC118 min
Jun 4, 2:29 PM EDTSevere Thunderstorm WatchSPC8 hr
Jun 4, 4:41 PM EDTMesoscale DiscussionSPC94 min
Jun 4, 7:56 PM EDTSevere Thunderstorm WarningLWX34 min
Jun 5, 3:40 AM EDTFlash Flood WatchLWX17 hr
Jun 5, 4:21 PM EDTAreal Flood WarningLWX13 hr
Jun 5, 4:47 PM EDTFlash Flood Warning Considerable damage threatLWX3 hr
Jun 10, 10:24 PM EDTSevere Thunderstorm WarningLWX26 min
Jun 16, 2:05 PM EDTCoastal Flood AdvisoryLWX17 hr
Jun 20, 10:45 AM EDTFlash Flood WatchLWX10 hr
Jun 20, 1:21 PM EDTAreal Flood WarningLWX92 min
Jun 22, 1:58 PM EDTMesoscale DiscussionSPC3 hr
Jun 22, 4:54 PM EDTSevere Thunderstorm WarningLWX51 min
Jun 22, 5:00 PM EDTSevere Thunderstorm WarningLWX45 min
Jun 22, 5:30 PM EDTSevere Thunderstorm WarningLWX45 min
Jun 22, 5:45 PM EDTFlash Flood Warning Considerable damage threatLWX96 min
Jun 22, 6:11 PM EDTSevere Thunderstorm WarningLWX30 min
Jun 22, 6:18 PM EDTFlash Flood Warning Considerable damage threatLWX104 min
Jun 23, 1:58 PM EDTFlash Flood WatchLWX10 hr
Jun 23, 6:37 PM EDTSevere Thunderstorm WarningLWX23 min
Jun 23, 6:50 PM EDTAreal Flood WarningLWX5 hr
Jun 23, 6:59 PM EDTSevere Thunderstorm WarningLWX26 min
Jun 25, 1:48 PM EDTMesoscale DiscussionSPC117 min
Jun 25, 6:09 PM EDTMesoscale DiscussionSPC96 min
Jun 28, 4:21 PM EDTSevere Thunderstorm WarningLWX17 min
Jul 5, 1:49 AM EDTCoastal Flood AdvisoryLWX10 hr
Jul 5, 1:50 PM EDTMesoscale DiscussionSPC115 min
Jul 5, 3:23 PM EDTSevere Thunderstorm WarningLWX52 min
Jul 5, 3:51 PM EDTSevere Thunderstorm WarningLWX39 min
Jul 5, 4:24 PM EDTSevere Thunderstorm WarningLWX51 min
Jul 6, 12:33 PM EDTMesoscale DiscussionSPC3 hr
Jul 6, 12:41 PM EDTFlash Flood WatchLWX15 hr
Jul 6, 1:38 PM EDTSevere Thunderstorm WatchSPC9 hr
Jul 6, 4:33 PM EDTMesoscale DiscussionSPC117 min
Jul 6, 6:05 PM EDTSevere Thunderstorm WarningLWX40 min
Jul 6, 6:25 PM EDTMesoscale DiscussionSPC2 hr
Jul 6, 6:44 PM EDTSevere Thunderstorm WarningLWX46 min
Jul 6, 8:39 PM EDTMesoscale DiscussionSPC2 hr
Jul 6, 9:04 PM EDTSevere Thunderstorm WarningLWX40 min
Jul 6, 9:32 PM EDTFlash Flood WarningLWX4 hr
Jul 6, 9:49 PM EDTFlash Flood WarningLWX80 min
Jul 8, 3:12 AM EDTCoastal Flood AdvisoryLWX11 hr
Jul 16, 9:57 PM EDTCoastal Flood AdvisoryLWX12 hr
Jul 18, 2:59 PM EDTHeat AdvisoryLWX29 hr
Jul 19, 2:47 PM EDTExcessive Heat WatchLWX5 hr
Jul 19, 2:47 PM EDTHeat AdvisoryLWX29 hr
Jul 21, 2:01 PM EDTMesoscale DiscussionSPC59 min
Jul 22, 12:07 AM EDTHeat AdvisoryLWX18 hr
Jul 22, 10:48 AM EDTMesoscale DiscussionSPC117 min
Jul 22, 12:01 PM EDTSevere Thunderstorm WatchSPC7 hr
Jul 22, 1:36 PM EDTFlash Flood WatchLWX4 hr
Jul 22, 3:56 PM EDTSevere Thunderstorm WarningLWX49 min
Jul 22, 4:21 PM EDTSevere Thunderstorm WarningLWX39 min
Jul 22, 4:27 PM EDTAreal Flood WarningLWX3 hr
Jul 22, 4:52 PM EDTSevere Thunderstorm WarningLWX38 min
Jul 22, 4:55 PM EDTMesoscale DiscussionSPC95 min
Jul 22, 5:08 PM EDTAreal Flood WarningLWX3 hr
Jul 24, 6:01 PM EDTFlash Flood WatchLWX3 hr
Jul 24, 6:06 PM EDTSevere Thunderstorm WarningLWX28 min
Jul 24, 6:11 PM EDTFlash Flood Warning Considerable damage threatLWX3 hr
Jul 24, 6:19 PM EDTAreal Flood WarningLWX2 hr
Jul 24, 6:34 PM EDTFlash Flood Warning Considerable damage threatLWX2 hr
Jul 24, 7:32 PM EDTFlash Flood Warning Considerable damage threatLWX72 min
Jul 28, 3:19 PM EDTMesoscale DiscussionSPC116 min
Jul 30, 1:06 PM EDTHeat AdvisoryLWX6 hr
Jul 30, 8:27 PM EDTSevere Thunderstorm WarningLWX48 min
Jul 30, 9:08 PM EDTSevere Thunderstorm WarningLWX37 min
Jul 30, 10:01 PM EDTFlash Flood WatchLWX20 hr
Aug 1, 4:00 PM EDTMesoscale DiscussionSPC2 hr
Aug 1, 7:05 PM EDTMesoscale DiscussionSPC115 min
Aug 2, 3:28 PM EDTFlash Flood WatchLWX45 hr
Aug 2, 4:56 PM EDTTropical Storm WatchLWX18 hr
Aug 2, 5:19 PM EDTCoastal Flood WatchLWX24 hr
Aug 3, 5:29 AM EDTTropical Storm WarningLWX36 hr
Aug 3, 5:15 PM EDTCoastal Flood WarningLWX29 hr
Aug 4, 1:41 AM EDTMesoscale DiscussionSPC3 hr
Aug 4, 2:26 AM EDTTornado WatchSPC9 hr
Aug 4, 8:39 AM EDTFlash Flood Warning Considerable damage threatLWX4 hr
Aug 4, 9:02 AM EDTFlash Flood Warning Considerable damage threatLWX4 hr
Aug 4, 9:31 AM EDTTornado WarningLWX11 min
Aug 4, 9:53 AM EDTAreal Flood WarningLWX6 hr
Aug 4, 12:32 PM EDTAreal Flood WarningLWX11 hr
Aug 4, 12:53 PM EDTAreal Flood WarningLWX4 hr
Aug 5, 10:51 PM EDTFlash Flood WatchLWX25 hr
Aug 6, 5:30 AM EDTAreal Flood WarningLWX5 hr
Aug 7, 3:46 AM EDTFlash Flood WatchLWX21 hr
Aug 7, 1:30 PM EDTMesoscale DiscussionSPC3 hr
Aug 7, 5:28 PM EDTAreal Flood WarningLWX4 hr
Aug 7, 5:36 PM EDTSevere Thunderstorm WarningLWX39 min
Aug 7, 6:12 PM EDTSevere Thunderstorm WarningLWX48 min
Aug 7, 7:39 PM EDTAreal Flood WarningLWX5 hr
Aug 7, 7:41 PM EDTFlash Flood Warning Considerable damage threatLWX104 min
Aug 11, 3:19 PM EDTFlash Flood WatchLWX52 hr
Aug 11, 4:23 PM EDTAreal Flood WarningLWX3 hr
Aug 11, 6:43 PM EDTAreal Flood WarningLWX100 min
Aug 12, 1:15 PM EDTMesoscale DiscussionSPC2 hr
Aug 12, 1:30 PM EDTAreal Flood WarningLWX57 min
Aug 12, 5:05 PM EDTSevere Thunderstorm WarningLWX40 min
Aug 12, 5:23 PM EDTSevere Thunderstorm WarningLWX38 min
Aug 12, 5:35 PM EDTAreal Flood WarningLWX7 hr
Aug 12, 5:42 PM EDTFlash Flood Warning Considerable damage threatLWX3 hr
Aug 12, 6:10 PM EDTFlash Flood Warning Considerable damage threatLWX3 hr
Aug 14, 6:57 PM EDTAreal Flood WarningLWX4 hr
Aug 14, 7:27 PM EDTAreal Flood WarningLWX4 hr
Aug 16, 9:08 PM EDTCoastal Flood AdvisoryLWX12 hr
Aug 17, 12:02 PM EDTCoastal Flood AdvisoryLWX24 hr
Aug 23, 3:57 PM EDTMesoscale DiscussionSPC2 hr
Aug 23, 4:23 PM EDTSevere Thunderstorm WarningLWX52 min
Aug 23, 6:58 PM EDTSevere Thunderstorm WarningLWX47 min
Aug 23, 7:34 PM EDTAreal Flood WarningLWX2 hr
Aug 23, 7:45 PM EDTFlash Flood Warning Considerable damage threatLWX81 min
Aug 24, 12:44 PM EDTMesoscale DiscussionSPC2 hr
Aug 25, 3:10 PM EDTMesoscale DiscussionSPC95 min
Aug 25, 3:34 PM EDTSevere Thunderstorm WatchSPC7 hr
Aug 25, 7:07 PM EDTMesoscale DiscussionSPC113 min
Aug 27, 6:35 PM EDTMesoscale DiscussionSPC115 min
Aug 28, 9:55 AM EDTMesoscale DiscussionSPC3 hr
Aug 28, 1:37 PM EDTSevere Thunderstorm WatchSPC8 hr
Aug 28, 3:07 PM EDTSevere Thunderstorm WarningLWX38 min
Aug 28, 3:19 PM EDTSevere Thunderstorm WarningLWX41 min
Aug 28, 3:45 PM EDTSevere Thunderstorm WarningLWX21 min
Aug 28, 3:50 PM EDTMesoscale DiscussionSPC85 min
Aug 28, 4:02 PM EDTSevere Thunderstorm WarningLWX43 min
Aug 28, 4:33 PM EDTSevere Thunderstorm WarningLWX42 min
Aug 28, 4:59 PM EDTFlash Flood WatchLWX11 hr
Aug 29, 12:08 PM EDTMesoscale DiscussionSPC3 hr
Sep 2, 3:37 PM EDTMesoscale DiscussionSPC53 min
Sep 2, 6:43 PM EDTSevere Thunderstorm WatchSPC5 hr
Sep 2, 7:36 PM EDTSevere Thunderstorm WarningLWX39 min
Sep 2, 8:20 PM EDTMesoscale DiscussionSPC115 min
Sep 3, 3:06 PM EDTMesoscale DiscussionSPC114 min
Sep 3, 3:42 PM EDTTornado WatchSPC6 hr
Sep 3, 4:31 PM EDTSevere Thunderstorm WarningLWX44 min
Sep 3, 4:36 PM EDTTornado WarningLWX24 min
Sep 3, 5:05 PM EDTTornado WarningLWX40 min
Sep 3, 5:33 PM EDTAreal Flood WarningLWX3 hr
Sep 9, 2:15 PM EDTFlash Flood WatchLWX30 hr
Sep 12, 6:37 PM EDTCoastal Flood AdvisoryLWX12 hr
Sep 21, 1:28 PM EDTCoastal Flood AdvisoryLWX20 hr
Sep 21, 1:31 PM EDTFrost AdvisoryLWX19 hr
Sep 23, 7:15 PM EDTCoastal Flood AdvisoryLWX10 hr
Oct 15, 1:38 PM EDTCoastal Flood AdvisoryLWX9 hr
Oct 17, 2:25 PM EDTFrost AdvisoryLWX20 hr
Oct 18, 3:21 PM EDTCoastal Flood AdvisoryLWX9 hr
Oct 21, 1:51 AM EDTDense Fog AdvisoryLWX9 hr
Oct 22, 1:01 AM EDTDense Fog AdvisoryLWX9 hr
Oct 22, 10:21 AM EDTDense Fog AdvisoryLWX99 min
Oct 23, 3:26 AM EDTDense Fog AdvisoryLWX8 hr
Oct 28, 3:05 PM EDTFlood WatchLWX25 hr
Oct 29, 3:24 AM EDTFreeze WatchLWX13 hr
Oct 29, 11:30 AM EDTAreal Flood WarningLWX6 hr
Oct 29, 4:14 PM EDTFreeze WarningLWX41 hr
Oct 29, 8:44 PM EDTFrost AdvisoryLWX36 hr
Oct 31, 8:59 AM EDTCoastal Flood AdvisoryLWX14 hr
Oct 31, 6:59 PM EDTWind AdvisoryLWX44 hr
Nov 1, 4:55 AM ESTCoastal Flood AdvisoryLWX16 hr
Nov 1, 8:45 PM ESTWind AdvisoryLWX3 hr
Nov 3, 8:41 PM ESTFrost AdvisoryLWX12 hr
Nov 9, 4:44 AM ESTDense Fog AdvisoryLWX5 hr
Nov 15, 7:03 AM ESTCoastal Flood AdvisoryLWX15 hr
Nov 15, 3:02 PM ESTCoastal Flood WarningLWX10 hr
Nov 15, 3:33 PM ESTMesoscale DiscussionSPC2 hr
Nov 15, 5:35 PM ESTSevere Thunderstorm WatchSPC5 hr
Nov 15, 6:28 PM ESTSevere Thunderstorm WarningLWX92 min
Nov 15, 6:52 PM ESTMesoscale DiscussionSPC113 min
Nov 29, 10:21 PM ESTCoastal Flood WatchLWX10 hr
Nov 30, 8:13 AM ESTCoastal Flood AdvisoryLWX16 hr
Nov 30, 1:07 PM ESTTornado WatchSPC6 hr
Nov 30, 1:11 PM ESTAreal Flood WarningLWX4 hr
Nov 30, 1:44 PM ESTAreal Flood WarningLWX5 hr
Dec 12, 7:09 AM ESTDense Fog AdvisoryLWX5 hr
Dec 14, 4:43 AM ESTWinter Storm WatchLWX35 hr
Dec 15, 4:09 AM ESTWinter Storm WarningLWX46 hr
Dec 15, 4:00 PM ESTWinter Weather AdvisoryLWX33 hr
Dec 21, 4:21 AM ESTDense Fog AdvisoryLWX8 hr
Dec 23, 4:27 AM ESTFlash Flood WatchLWX47 hr
Dec 23, 4:34 AM ESTCoastal Flood WatchLWX37 hr
Dec 23, 9:07 PM ESTWind AdvisoryLWX29 hr
Dec 24, 5:54 PM ESTCoastal Flood WarningLWX13 hr
Dec 24, 5:54 PM ESTCoastal Flood AdvisoryLWX24 hr
Dec 25, 2:11 AM ESTAreal Flood WarningLWX9 hr
Dec 25, 2:18 AM ESTAreal Flood WarningLWX6 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 archive20192021

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.