Alert archive / Maryland / Washington County

Weather alerts in Washington County, Maryland, 2011

256 weather alerts in 2011, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Washington County and its neighbors

Each county as a circle sized by its count in 2011. Tap one for its archive.

Alerts
256
Warnings
96
Watches
43
Advisories
27
Busiest month
April55 alerts
Busiest day
April 16, 201114 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 5 tornado warnings covering Washington County in 2011 had a tornado report inside them; 0 of 2 tornado reports fell inside a warning.

Washington County, 2011

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings50100%20%
Severe thunderstorm warnings554616%3080%14 min
Flash flood warnings9544%3100%186 min

Each office's whole area, 2011

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Baltimore/Washington: tornado warnings962772%4567%11 min
NWS Baltimore/Washington: severe thunderstorm warnings44033524%96378%18 min
NWS Baltimore/Washington: flash flood warnings1709942%34184%121 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 7, 6:50 PM ESTWinter Weather AdvisoryLWX35 hr
Jan 10, 9:39 PM ESTWinter Weather AdvisoryLWX55 hr
Jan 17, 2:44 PM ESTWinter Weather AdvisoryLWX20 hr
Jan 18, 11:32 PM ESTFreezing Rain AdvisoryLWX6 hr
Jan 20, 8:54 AM ESTWinter Weather AdvisoryLWX24 hr
Jan 25, 10:16 AM ESTWinter Storm WatchLWX18 hr
Jan 25, 6:02 PM ESTWinter Storm WarningLWX29 hr
Jan 26, 7:30 AM ESTMesoscale DiscussionSPC5 hr
Jan 31, 4:07 AM ESTWinter Storm WatchLWX32 hr
Jan 31, 2:40 PM ESTWinter Weather AdvisoryLWX21 hr
Feb 1, 11:57 AM ESTFreezing Rain AdvisoryLWX19 hr
Feb 1, 8:39 PM ESTMesoscale DiscussionSPC6 hr
Feb 4, 2:44 PM ESTFreezing Rain AdvisoryLWX22 hr
Feb 8, 3:26 AM ESTWind AdvisoryLWX13 hr
Feb 14, 2:45 AM ESTWind AdvisoryLWX22 hr
Feb 18, 3:16 AM ESTFire Weather WatchLWX11 hr
Feb 18, 10:30 AM ESTHigh Wind WatchLWX7 hr
Feb 18, 2:03 PM ESTRed Flag WarningLWX31 hr
Feb 18, 5:22 PM ESTHigh Wind WarningLWX26 hr
Feb 18, 5:22 PM ESTWind AdvisoryLWX19 hr
Feb 19, 6:33 PM ESTWind AdvisoryLWX5 hr
Feb 21, 3:51 AM ESTWinter Storm WatchLWX8 hr
Feb 21, 11:57 AM ESTWinter Storm WarningLWX18 hr
Feb 21, 5:58 PM ESTMesoscale DiscussionSPC4 hr
Feb 21, 6:33 PM ESTMesoscale DiscussionSPC5 hr
Feb 24, 4:05 AM ESTHigh Wind WatchLWX10 hr
Feb 24, 1:41 PM ESTWind AdvisoryLWX24 hr
Feb 24, 8:36 PM ESTHigh Wind WarningLWX22 hr
Feb 28, 8:36 AM ESTMesoscale DiscussionSPC24 min
Feb 28, 8:57 AM ESTTornado WatchSPC9 hr
Feb 28, 9:31 AM ESTSpecial Weather StatementLWX29 min
Feb 28, 9:40 AM ESTSevere Thunderstorm WarningLWX50 min
Mar 5, 3:16 AM ESTFlood WatchLWX43 hr
Mar 6, 2:37 PM ESTWinter Weather AdvisoryLWX12 hr
Mar 6, 10:10 PM ESTRiver Flood WarningLWX13 hr
Mar 8, 3:14 AM ESTFlood WatchLWX65 hr
Mar 9, 2:43 PM ESTRiver Flood WarningLWX54 hr
Mar 9, 3:32 PM ESTRiver Flood WarningLWX3 days
Mar 10, 5:34 PM ESTSevere Thunderstorm WarningLWX41 min
Mar 10, 6:06 PM ESTSpecial Weather StatementLWX24 min
Mar 10, 6:07 PM ESTFlash Flood WarningLWX3 hr
Mar 10, 6:38 PM ESTAreal Flood WarningLWX3 hr
Mar 23, 3:54 PM EDTMesoscale DiscussionSPC96 min
Mar 23, 4:13 PM EDTSevere Thunderstorm WatchSPC5 hr
Mar 23, 7:03 PM EDTSpecial Weather StatementLWX42 min
Apr 3, 7:52 PM EDTSpecial Weather StatementLWX23 min
Apr 3, 8:18 PM EDTSpecial Weather StatementLWX27 min
Apr 3, 8:52 PM EDTSpecial Weather StatementLWX23 min
Apr 3, 9:19 PM EDTSpecial Weather StatementLWX26 min
Apr 3, 10:06 PM EDTSpecial Weather StatementLWX39 min
Apr 11, 7:12 PM EDTSpecial Weather StatementLWX33 min
Apr 15, 4:34 AM EDTFlash Flood WatchLWX41 hr
Apr 15, 11:54 AM EDTWind AdvisoryLWX29 hr
Apr 16, 12:52 PM EDTMesoscale DiscussionSPC113 min
Apr 16, 1:29 PM EDTTornado WatchSPC8 hr
Apr 16, 2:58 PM EDTSevere Thunderstorm WarningLWX47 min
Apr 16, 3:18 PM EDTSpecial Weather StatementLWX57 min
Apr 16, 3:19 PM EDTSpecial Weather StatementLWX56 min
Apr 16, 3:29 PM EDTAreal Flood WarningLWX7 hr
Apr 16, 4:19 PM EDTSevere Thunderstorm WarningLWX41 min
Apr 16, 4:29 PM EDTMesoscale DiscussionSPC31 min
Apr 16, 4:53 PM EDTAreal Flood WarningLWX5 hr
Apr 16, 5:02 PM EDTSpecial Weather StatementLWX28 min
Apr 16, 6:35 PM EDTSevere Thunderstorm WarningLWX40 min
Apr 16, 6:38 PM EDTMesoscale DiscussionSPC97 min
Apr 16, 7:01 PM EDTSevere Thunderstorm WarningLWX44 min
Apr 16, 7:44 PM EDTRiver Flood WarningLWX26 hr
Apr 16, 9:20 PM EDTWind AdvisoryLWX22 hr
Apr 16, 10:03 PM EDTRiver Flood WarningLWX37 hr
Apr 16, 10:14 PM EDTRiver Flood WarningLWX42 hr
Apr 16, 11:27 PM EDTAreal Flood WarningLWX17 hr
Apr 17, 4:02 AM EDTSpecial Weather StatementLWX58 min
Apr 19, 9:54 AM EDTFlood WatchLWX8 hr
Apr 21, 2:05 PM EDTFlood WatchLWX44 hr
Apr 23, 4:06 AM EDTFlash Flood WatchLWX18 hr
Apr 23, 9:05 PM EDTSpecial Weather StatementLWX40 min
Apr 24, 2:12 PM EDTMesoscale DiscussionSPC93 min
Apr 26, 1:18 PM EDTMesoscale DiscussionSPC57 min
Apr 26, 2:09 PM EDTSevere Thunderstorm WatchSPC7 hr
Apr 26, 4:34 PM EDTMesoscale DiscussionSPC56 min
Apr 26, 7:44 PM EDTMesoscale DiscussionSPC61 min
Apr 27, 9:51 AM EDTFlash Flood WatchLWX29 hr
Apr 27, 1:23 PM EDTTornado WatchSPC5 hr
Apr 27, 4:39 PM EDTMesoscale DiscussionSPC66 min
Apr 27, 6:15 PM EDTTornado WatchSPC6 hr
Apr 27, 6:50 PM EDTMesoscale DiscussionSPC55 min
Apr 27, 8:19 PM EDTSevere Thunderstorm WarningLWX36 min
Apr 27, 8:28 PM EDTSevere Thunderstorm WarningLWX19 min
Apr 28, 12:27 AM EDTMesoscale DiscussionSPC63 min
Apr 28, 12:41 AM EDTTornado WatchSPC7 hr
Apr 28, 1:29 AM EDTSevere Thunderstorm WarningLWX35 min
Apr 28, 1:33 AM EDTFlash Flood WarningLWX4 hr
Apr 28, 2:59 AM EDTSevere Thunderstorm WarningLWX62 min
Apr 28, 3:04 AM EDTFlash Flood WarningLWX7 hr
Apr 28, 4:24 AM EDTTornado WarningLWX51 min
Apr 28, 8:01 AM EDTFlash Flood WarningLWX119 min
Apr 28, 9:58 AM EDTAreal Flood WarningLWX3 hr
Apr 28, 10:44 AM EDTMesoscale DiscussionSPC61 min
Apr 28, 12:28 PM EDTRiver Flood WarningLWX11 hr
Apr 28, 9:43 PM EDTRiver Flood WarningLWX10 hr
May 3, 2:27 PM EDTMesoscale DiscussionSPC2 hr
May 3, 3:47 PM EDTSevere Thunderstorm WatchSPC6 hr
May 3, 6:51 PM EDTMesoscale DiscussionSPC84 min
May 17, 3:45 AM EDTFlash Flood WatchLWX44 hr
May 17, 5:18 PM EDTSpecial Weather StatementLWX27 min
May 17, 5:45 PM EDTFlash Flood WarningLWX3 hr
May 17, 6:27 PM EDTMesoscale DiscussionSPC2 hr
May 17, 8:17 PM EDTTornado WarningLWX11 min
May 18, 6:31 AM EDTRiver Flood WarningLWX45 hr
May 18, 9:47 AM EDTRiver Flood WarningLWX28 hr
May 18, 11:23 AM EDTTornado WarningLWX22 min
May 18, 11:55 AM EDTMesoscale DiscussionSPC65 min
May 18, 12:55 PM EDTSevere Thunderstorm WatchSPC8 hr
May 18, 3:08 PM EDTMesoscale DiscussionSPC67 min
May 18, 3:12 PM EDTSevere Thunderstorm WarningLWX33 min
May 18, 3:44 PM EDTSevere Thunderstorm WarningLWX19 min
May 18, 5:01 PM EDTSpecial Weather StatementLWX29 min
May 18, 6:01 PM EDTMesoscale DiscussionSPC89 min
May 19, 4:36 AM EDTFlash Flood WatchLWX14 hr
May 23, 10:33 AM EDTMesoscale DiscussionSPC87 min
May 23, 10:48 AM EDTSevere Thunderstorm WatchSPC9 hr
May 23, 2:33 PM EDTMesoscale DiscussionSPC87 min
May 23, 4:37 PM EDTSpecial Weather StatementLWX23 min
May 23, 4:40 PM EDTMesoscale DiscussionSPC95 min
May 26, 1:42 PM EDTSevere Thunderstorm WatchSPC11 hr
May 26, 4:29 PM EDTTornado WarningLWX31 min
May 26, 4:51 PM EDTTornado WarningLWX39 min
May 26, 5:24 PM EDTSevere Thunderstorm WarningLWX22 min
May 26, 5:27 PM EDTSevere Thunderstorm WarningLWX48 min
May 26, 5:54 PM EDTSevere Thunderstorm WarningLWX51 min
May 26, 6:26 PM EDTSevere Thunderstorm WarningLWX45 min
May 26, 6:40 PM EDTSpecial Weather StatementLWX65 min
May 26, 6:46 PM EDTSevere Thunderstorm WarningLWX59 min
May 27, 1:00 AM EDTSevere Thunderstorm WarningLWX45 min
May 27, 12:24 PM EDTMesoscale DiscussionSPC96 min
May 27, 12:57 PM EDTSevere Thunderstorm WatchSPC9 hr
May 27, 6:14 PM EDTMesoscale DiscussionSPC2 hr
May 27, 7:29 PM EDTSevere Thunderstorm WarningLWX46 min
May 27, 7:59 PM EDTSpecial Weather StatementLWX46 min
May 27, 8:08 PM EDTSevere Thunderstorm WarningLWX22 min
Jun 1, 2:24 PM EDTSevere Thunderstorm WatchSPC7 hr
Jun 1, 3:02 PM EDTSpecial Weather StatementLWX28 min
Jun 1, 3:07 PM EDTSevere Thunderstorm WarningLWX38 min
Jun 8, 1:28 PM EDTHeat AdvisoryLWX31 hr
Jun 9, 12:53 PM EDTSevere Thunderstorm WatchSPC7 hr
Jun 9, 6:17 PM EDTMesoscale DiscussionSPC58 min
Jun 9, 10:19 PM EDTSpecial Weather StatementLWX26 min
Jun 10, 3:00 PM EDTSpecial Weather StatementLWX30 min
Jun 10, 5:28 PM EDTMesoscale DiscussionSPC92 min
Jun 11, 6:47 PM EDTSpecial Weather StatementLWX28 min
Jun 11, 7:17 PM EDTSpecial Weather StatementLWX28 min
Jun 12, 12:03 PM EDTMesoscale DiscussionSPC87 min
Jun 12, 1:46 PM EDTSpecial Weather StatementLWX29 min
Jun 12, 1:48 PM EDTSevere Thunderstorm WatchSPC6 hr
Jun 12, 2:10 PM EDTSevere Thunderstorm WarningLWX50 min
Jun 12, 2:56 PM EDTSevere Thunderstorm WarningLWX34 min
Jun 12, 3:16 PM EDTSevere Thunderstorm WarningLWX44 min
Jun 16, 6:01 PM EDTMesoscale DiscussionSPC89 min
Jun 16, 10:17 PM EDTSpecial Weather StatementLWX43 min
Jun 21, 6:12 PM EDTSevere Thunderstorm WarningLWX48 min
Jun 22, 12:50 AM EDTSpecial Weather StatementLWX20 min
Jun 22, 2:03 PM EDTMesoscale DiscussionSPC117 min
Jul 3, 3:14 PM EDTSevere Thunderstorm WarningLWX46 min
Jul 3, 3:22 PM EDTMesoscale DiscussionSPC53 min
Jul 3, 3:56 PM EDTSevere Thunderstorm WarningLWX49 min
Jul 3, 4:21 PM EDTSevere Thunderstorm WatchSPC7 hr
Jul 4, 7:28 PM EDTSpecial Weather StatementLWX32 min
Jul 4, 8:10 PM EDTSpecial Weather StatementLWX35 min
Jul 7, 10:54 PM EDTSpecial Weather StatementLWX36 min
Jul 7, 11:28 PM EDTFlash Flood WarningLWX3 hr
Jul 8, 11:44 AM EDTMesoscale DiscussionSPC61 min
Jul 8, 3:24 PM EDTFlash Flood WarningLWX3 hr
Jul 9, 4:19 AM EDTDense Fog AdvisoryLWX4 hr
Jul 11, 5:47 PM EDTSevere Thunderstorm WatchSPC5 hr
Jul 11, 6:40 PM EDTSevere Thunderstorm WarningLWX35 min
Jul 11, 7:05 PM EDTSevere Thunderstorm WarningLWX40 min
Jul 11, 7:10 PM EDTSevere Thunderstorm WarningLWX35 min
Jul 11, 7:44 PM EDTMesoscale DiscussionSPC61 min
Jul 19, 12:12 PM EDTExcessive Heat WatchLWX27 hr
Jul 19, 5:23 PM EDTSpecial Weather StatementLWX22 min
Jul 19, 5:57 PM EDTSpecial Weather StatementLWX48 min
Jul 19, 6:00 PM EDTSevere Thunderstorm WarningLWX45 min
Jul 20, 3:19 PM EDTExcessive Heat WarningLWX31 hr
Jul 20, 3:19 PM EDTExcessive Heat WarningLWX54 hr
Jul 21, 3:38 PM EDTHeat AdvisoryLWX52 hr
Jul 22, 2:00 PM EDTSpecial Weather StatementLWX30 min
Jul 22, 2:07 PM EDTSevere Thunderstorm WarningLWX38 min
Jul 22, 2:43 PM EDTSevere Thunderstorm WarningLWX47 min
Jul 22, 2:56 PM EDTFlash Flood WarningLWX106 min
Jul 22, 3:07 PM EDTSevere Thunderstorm WarningLWX38 min
Jul 22, 3:07 PM EDTSevere Thunderstorm WarningLWX45 min
Jul 22, 3:17 PM EDTMesoscale DiscussionSPC58 min
Jul 22, 3:33 PM EDTSpecial Weather StatementLWX27 min
Jul 28, 12:53 PM EDTHeat AdvisoryLWX31 hr
Jul 29, 6:17 PM EDTMesoscale DiscussionSPC88 min
Jul 29, 6:34 PM EDTSpecial Weather StatementLWX26 min
Jul 29, 6:58 PM EDTSevere Thunderstorm WarningLWX32 min
Aug 1, 3:22 PM EDTMesoscale DiscussionSPC83 min
Aug 1, 5:54 PM EDTSevere Thunderstorm WarningLWX51 min
Aug 1, 6:13 PM EDTSevere Thunderstorm WarningLWX47 min
Aug 13, 2:07 PM EDTMesoscale DiscussionSPC113 min
Aug 13, 2:13 PM EDTSevere Thunderstorm WarningLWX62 min
Aug 14, 3:47 PM EDTMesoscale DiscussionSPC58 min
Aug 14, 7:44 PM EDTSevere Thunderstorm WarningLWX42 min
Aug 18, 8:23 PM EDTSpecial Weather StatementLWX37 min
Aug 18, 8:30 PM EDTSevere Thunderstorm WarningLWX30 min
Aug 18, 9:29 PM EDTSpecial Weather StatementLWX46 min
Aug 18, 9:39 PM EDTSevere Thunderstorm WarningLWX51 min
Aug 18, 10:11 PM EDTSevere Thunderstorm WarningLWX49 min
Aug 18, 10:36 PM EDTSevere Thunderstorm WarningLWX39 min
Aug 19, 3:54 PM EDTSevere Thunderstorm WarningLWX32 min
Aug 19, 4:25 PM EDTSpecial Weather StatementCTP65 min
Aug 19, 4:53 PM EDTSevere Thunderstorm WarningLWX39 min
Aug 21, 11:54 AM EDTMesoscale DiscussionSPC2 hr
Aug 21, 12:52 PM EDTSevere Thunderstorm WatchSPC8 hr
Aug 21, 1:40 PM EDTSevere Thunderstorm WarningLWX50 min
Aug 21, 7:12 PM EDTMesoscale DiscussionSPC63 min
Aug 25, 7:29 AM EDTSpecial Weather StatementLWX31 min
Sep 5, 4:06 AM EDTFlash Flood WatchLWX5 days
Sep 6, 12:26 PM EDTRiver Flood WatchLWX22 hr
Sep 6, 12:26 PM EDTRiver Flood WatchLWX19 hr
Sep 6, 12:26 PM EDTRiver Flood WatchLWX29 hr
Sep 6, 12:29 PM EDTRiver Flood WatchLWX5 hr
Sep 6, 5:13 PM EDTRiver Flood WarningLWX24 hr
Sep 6, 5:24 PM EDTRiver Flood WatchLWX24 hr
Sep 9, 8:27 PM EDTRiver Flood WarningLWX25 hr
Sep 11, 6:38 PM EDTMesoscale DiscussionSPC97 min
Sep 11, 6:56 PM EDTSpecial Weather StatementLWX34 min
Sep 11, 7:41 PM EDTSpecial Weather StatementLWX49 min
Sep 14, 3:22 PM EDTMesoscale DiscussionSPC53 min
Sep 14, 3:26 PM EDTSpecial Weather StatementLWX49 min
Sep 14, 4:04 PM EDTSevere Thunderstorm WarningLWX41 min
Sep 14, 4:42 PM EDTSevere Thunderstorm WarningLWX48 min
Sep 14, 4:44 PM EDTSevere Thunderstorm WarningLWX46 min
Sep 14, 5:28 PM EDTSevere Thunderstorm WarningLWX47 min
Sep 14, 5:34 PM EDTSevere Thunderstorm WarningLWX41 min
Sep 14, 6:01 PM EDTSevere Thunderstorm WarningLWX44 min
Sep 14, 6:10 PM EDTFlash Flood WarningLWX68 min
Sep 14, 6:32 PM EDTSevere Thunderstorm WarningLWX43 min
Sep 14, 6:37 PM EDTSevere Thunderstorm WarningLWX38 min
Sep 23, 5:10 AM EDTDense Fog AdvisoryLWX4 hr
Sep 23, 9:31 PM EDTDense Fog AdvisoryLWX11 hr
Sep 27, 12:33 PM EDTSpecial Weather StatementLWX27 min
Sep 29, 5:04 AM EDTDense Fog AdvisoryLWX4 hr
Oct 7, 2:47 PM EDTDense Fog AdvisoryLWX15 hr
Oct 26, 4:24 PM EDTFreeze WatchLWX23 hr
Oct 27, 3:08 PM EDTFrost AdvisoryLWX17 hr
Oct 28, 3:36 AM EDTWinter Storm WatchLWX15 hr
Oct 28, 2:31 PM EDTWinter Storm WarningLWX27 hr
Oct 29, 12:34 AM EDTMesoscale DiscussionSPC6 hr
Oct 29, 7:36 AM EDTMesoscale DiscussionSPC5 hr
Oct 29, 10:32 AM EDTFreeze WarningLWX22 hr
Nov 23, 2:44 AM ESTRiver Flood WarningLWX19 hr
Nov 23, 3:12 AM ESTWind AdvisoryLWX16 hr
Dec 6, 8:24 PM ESTFlood WatchLWX29 hr
Dec 7, 4:30 AM ESTWinter Weather AdvisoryLWX20 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 archive20102012

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.