Weather alerts in District of Columbia, 2021

212 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered any part of the state, so the counties below add up to more than the state.

Alerts: 212
Warnings: 78
Watches: 41
Advisories: 93
Busiest month: August46 alerts
Busiest day: September 1, 20217 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 District of Columbia in 2021 had a tornado report inside them; 2 of 2 tornado reports fell inside a warning, on average 6 minutes after it went out.

District of Columbia, 2021

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	2	1	50%	2	100%	6 min
Severe thunderstorm warnings	35	33	6%	45	87%	17 min
Flash flood warnings	11	8	27%	7	86%	57 min

Each office's whole area, 2021

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Baltimore/Washington: tornado warnings	49	10	80%	13	100%	11 min
NWS Baltimore/Washington: severe thunderstorm warnings	544	396	27%	1,446	83%	20 min
NWS Baltimore/Washington: flash flood warnings	76	32	58%	96	77%	60 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, Central Time. Each opens its own page with the text, the map, the radar and the sounding.

Issued	Product	Office	Lasted
Jan 5, 10:59 AM CST	Coastal Flood Advisory	LWX	2 hr
Jan 5, 7:40 PM CST	Coastal Flood Advisory	LWX	5 hr
Jan 8, 2:03 PM CST	Coastal Flood Advisory	LWX	83 min
Jan 15, 4:01 PM CST	Coastal Flood Advisory	LWX	6 hr
Jan 16, 1:11 PM CST	Coastal Flood Advisory	LWX	9 hr
Jan 25, 12:05 AM CST	Winter Weather Advisory	LWX	36 hr
Jan 29, 2:10 PM CST	Winter Storm Watch	LWX	23 hr
Jan 30, 8:02 AM CST	Winter Storm Warning	LWX	69 hr
Jan 31, 5:50 PM CST	Winter Weather Advisory	LWX	42 hr
Jan 31, 7:42 PM CST	Coastal Flood Advisory	LWX	3 hr
Feb 5, 2:13 PM CST	Winter Storm Watch	LWX	12 hr
Feb 6, 2:22 AM CST	Winter Storm Warning	LWX	33 hr
Feb 6, 2:22 AM CST	Winter Weather Advisory	LWX	33 hr
Feb 10, 2:33 AM CST	Winter Weather Advisory	LWX	30 hr
Feb 11, 5:08 PM CST	Winter Storm Watch	LWX	21 hr
Feb 12, 2:10 PM CST	Ice Storm Warning	LWX	30 hr
Feb 12, 2:10 PM CST	Winter Weather Advisory	LWX	43 hr
Feb 16, 3:56 AM CST	Winter Storm Watch	LWX	29 hr
Feb 16, 7:38 AM CST	Coastal Flood Advisory	LWX	3 hr
Feb 17, 2:24 AM CST	Winter Storm Warning	LWX	57 hr
Feb 18, 12:05 PM CST	Winter Weather Advisory	LWX	23 hr
Feb 22, 7:22 PM CST	Wind Advisory	LWX	22 hr
Feb 28, 8:09 PM CST	Dense Fog Advisory	LWX	8 hr
Mar 1, 8:41 AM CST	Coastal Flood Advisory	LWX	79 min
Mar 2, 2:52 PM CST	Coastal Flood Advisory	LWX	18 hr
Mar 10, 2:43 PM CST	Fire Weather Watch	LWX	12 hr
Mar 11, 2:28 AM CST	Red Flag Warning	LWX	15 hr
Mar 13, 12:53 PM CST	Fire Weather Watch	LWX	13 hr
Mar 14, 3:01 AM CDT	Red Flag Warning	LWX	18 hr
Mar 20, 2:12 AM CDT	Coastal Flood Advisory	LWX	12 hr
Mar 24, 8:09 PM CDT	Dense Fog Advisory	LWX	14 hr
Mar 25, 1:41 PM CDT	Wind Advisory	LWX	27 hr
Mar 28, 3:16 AM CDT	Wind Advisory	LWX	23 hr
Mar 28, 4:05 PM CDT	Severe Thunderstorm Watch	SPC	4 hr
Apr 8, 4:57 PM CDT	Coastal Flood Advisory	LWX	2 hr
Apr 9, 4:53 AM CDT	Coastal Flood Advisory	LWX	3 hr
Apr 10, 5:15 AM CDT	Coastal Flood Advisory	LWX	3 hr
Apr 11, 7:33 AM CDT	Coastal Flood Advisory	LWX	87 min
Apr 12, 8:38 PM CDT	Coastal Flood Advisory	LWX	14 hr
Apr 13, 6:54 PM CDT	Coastal Flood Advisory	LWX	4 hr
Apr 13, 8:05 PM CDT	Coastal Flood Advisory	LWX	15 hr
Apr 15, 8:27 AM CDT	Coastal Flood Advisory	LWX	3 hr
Apr 21, 1:47 PM CDT	Wind Advisory	LWX	5 hr
Apr 22, 11:03 AM CDT	Frost Advisory	LWX	20 hr
Apr 29, 2:59 AM CDT	High Wind Watch	LWX	16 hr
Apr 29, 7:18 PM CDT	High Wind Warning	LWX	25 hr
Apr 29, 7:18 PM CDT	Wind Advisory	LWX	30 hr
Apr 30, 3:39 PM CDT	Severe Thunderstorm Warning	LWX	36 min
May 4, 12:51 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
May 4, 3:55 PM CDT	Severe Thunderstorm Warning	LWX	50 min
May 25, 2:10 AM CDT	Coastal Flood Advisory	LWX	5 hr
May 25, 2:03 PM CDT	Coastal Flood Advisory	LWX	19 hr
May 26, 1:48 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
May 26, 3:54 PM CDT	Severe Thunderstorm Warning	LWX	66 min
May 26, 6:59 PM CDT	Severe Thunderstorm Warning	LWX	46 min
May 26, 7:21 PM CDT	Severe Thunderstorm Warning	LWX	39 min
May 26, 8:19 PM CDT	Severe Thunderstorm Warning	LWX	41 min
May 29, 4:09 AM CDT	Coastal Flood Advisory	LWX	6 hr
May 30, 2:02 AM CDT	Coastal Flood Advisory	LWX	11 hr
Jun 3, 1:48 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 4, 11:36 AM CDT	Severe Thunderstorm Warning	LWX	39 min
Jun 8, 5:23 PM CDT	Areal Flood Warning	LWX	3 hr
Jun 10, 1:53 AM CDT	Flash Flood Watch	LWX	43 hr
Jun 11, 2:15 AM CDT	Coastal Flood Advisory	LWX	8 hr
Jun 11, 1:47 PM CDT	Coastal Flood Advisory	LWX	22 hr
Jun 12, 7:43 PM CDT	Coastal Flood Advisory	LWX	15 hr
Jun 14, 2:07 AM CDT	Coastal Flood Advisory	LWX	10 hr
Jun 14, 6:29 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 14, 9:25 PM CDT	Flash Flood Watch	LWX	4 hr
Jun 14, 9:30 PM CDT	Severe Thunderstorm Warning	LWX	45 min
Jun 14, 9:49 PM CDT	Flash Flood Warning Considerable damage threat	LWX	3 hr
Jun 15, 12:43 AM CDT	Areal Flood Warning	LWX	17 min
Jun 15, 12:53 AM CDT	Areal Flood Warning	LWX	4 hr
Jun 15, 9:01 AM CDT	Coastal Flood Advisory	LWX	2 hr
Jun 21, 1:20 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 21, 4:02 PM CDT	Severe Thunderstorm Warning	LWX	43 min
Jun 24, 4:36 AM CDT	Coastal Flood Advisory	LWX	3 hr
Jun 30, 1:23 PM CDT	Flash Flood Watch	LWX	42 hr
Jul 1, 11:46 AM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 1, 12:03 PM CDT	Severe Thunderstorm Warning	LWX	42 min
Jul 1, 12:44 PM CDT	Severe Thunderstorm Warning	LWX	46 min
Jul 1, 1:43 PM CDT	Severe Thunderstorm Warning	LWX	47 min
Jul 1, 2:14 PM CDT	Flash Flood Warning Considerable damage threat	LWX	3 hr
Jul 1, 7:30 PM CDT	Flash Flood Warning Considerable damage threat	LWX	2 hr
Jul 1, 7:47 PM CDT	Severe Thunderstorm Warning	LWX	43 min
Jul 1, 7:58 PM CDT	Tornado Warning	LWX	32 min
Jul 1, 8:13 PM CDT	Tornado Warning	LWX	21 min
Jul 1, 9:45 PM CDT	Areal Flood Warning	LWX	3 hr
Jul 7, 2:12 PM CDT	Flash Flood Watch	LWX	33 hr
Jul 9, 4:25 AM CDT	Coastal Flood Advisory	LWX	3 hr
Jul 9, 4:02 PM CDT	Areal Flood Warning	LWX	3 hr
Jul 16, 1:57 PM CDT	Heat Advisory	LWX	28 hr
Jul 16, 9:20 PM CDT	Flash Flood Watch	LWX	24 hr
Jul 17, 12:13 PM CDT	Severe Thunderstorm Watch	SPC	10 hr
Jul 21, 10:56 AM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 21, 12:14 PM CDT	Severe Thunderstorm Warning	LWX	46 min
Jul 24, 11:31 PM CDT	Coastal Flood Advisory	LWX	13 hr
Jul 26, 5:46 PM CDT	Severe Thunderstorm Warning	LWX	44 min
Jul 26, 6:07 PM CDT	Severe Thunderstorm Warning	LWX	23 min
Jul 26, 6:30 PM CDT	Severe Thunderstorm Warning	LWX	14 min
Jul 26, 6:36 PM CDT	Severe Thunderstorm Warning	LWX	24 min
Jul 28, 8:48 PM CDT	Severe Thunderstorm Warning	LWX	42 min
Jul 29, 2:00 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 29, 4:01 PM CDT	Severe Thunderstorm Warning	LWX	29 min
Jul 29, 4:30 PM CDT	Severe Thunderstorm Warning	LWX	40 min
Aug 9, 5:23 PM CDT	Severe Thunderstorm Warning	LWX	52 min
Aug 9, 5:39 PM CDT	Flash Flood Warning Considerable damage threat	LWX	3 hr
Aug 9, 6:28 PM CDT	Severe Thunderstorm Warning	LWX	29 min
Aug 9, 8:32 PM CDT	Areal Flood Warning	LWX	105 min
Aug 10, 12:33 PM CDT	Excessive Heat Watch	LWX	37 hr
Aug 10, 12:33 PM CDT	Heat Advisory	LWX	29 hr
Aug 10, 4:25 PM CDT	Severe Thunderstorm Warning	LWX	50 min
Aug 10, 4:53 PM CDT	Severe Thunderstorm Warning	LWX	29 min
Aug 11, 1:02 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 11, 3:20 PM CDT	Severe Thunderstorm Warning	LWX	40 min
Aug 11, 3:45 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LWX	30 min
Aug 12, 1:15 AM CDT	Heat Advisory	LWX	18 hr
Aug 12, 5:04 PM CDT	Heat Advisory	LWX	25 hr
Aug 13, 12:11 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Aug 13, 3:46 PM CDT	Severe Thunderstorm Warning	LWX	29 min
Aug 13, 4:11 PM CDT	Severe Thunderstorm Warning	LWX	49 min
Aug 13, 4:56 PM CDT	Severe Thunderstorm Warning	LWX	49 min
Aug 14, 5:14 PM CDT	Flash Flood Watch	LWX	10 hr
Aug 14, 11:13 PM CDT	Flash Flood Warning Considerable damage threat	LWX	3 hr
Aug 14, 11:42 PM CDT	Flash Flood Warning Considerable damage threat	LWX	2 hr
Aug 16, 4:24 PM CDT	Flash Flood Warning Considerable damage threat	LWX	2 hr
Aug 16, 10:32 PM CDT	Flash Flood Warning Considerable damage threat	LWX	3 hr
Aug 17, 1:17 AM CDT	Areal Flood Warning	LWX	4 hr
Aug 17, 1:37 AM CDT	Coastal Flood Advisory	LWX	2 hr
Aug 17, 12:54 PM CDT	Flash Flood Watch	LWX	27 hr
Aug 17, 5:40 PM CDT	Coastal Flood Advisory	LWX	11 hr
Aug 18, 10:37 AM CDT	Tornado Watch	SPC	11 hr
Aug 18, 3:31 PM CDT	Coastal Flood Advisory	LWX	2 hr
Aug 18, 6:01 PM CDT	Coastal Flood Advisory	LWX	14 hr
Aug 19, 1:11 PM CDT	Flash Flood Watch	LWX	28 hr
Aug 20, 6:35 AM CDT	Areal Flood Warning	LWX	9 hr
Aug 20, 6:55 AM CDT	Flash Flood Warning Considerable damage threat	LWX	2 hr
Aug 20, 7:21 AM CDT	Flash Flood Warning Considerable damage threat	LWX	101 min
Aug 21, 2:12 PM CDT	Areal Flood Warning	LWX	2 hr
Aug 22, 7:31 AM CDT	Coastal Flood Advisory	LWX	89 min
Aug 23, 1:57 AM CDT	Coastal Flood Advisory	LWX	8 hr
Aug 26, 2:31 PM CDT	Severe Thunderstorm Warning	LWX	44 min
Aug 26, 2:45 PM CDT	Areal Flood Warning	LWX	3 hr
Aug 26, 3:03 PM CDT	Severe Thunderstorm Warning	LWX	42 min
Aug 27, 1:56 AM CDT	Flash Flood Watch	LWX	17 hr
Aug 27, 2:05 PM CDT	Severe Thunderstorm Warning	LWX	40 min
Aug 27, 2:36 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LWX	19 min
Aug 27, 3:11 PM CDT	Areal Flood Warning	LWX	3 hr
Aug 27, 3:44 PM CDT	Areal Flood Warning	LWX	3 hr
Aug 30, 3:54 AM CDT	Flash Flood Watch	LWX	62 hr
Aug 30, 10:48 AM CDT	Flash Flood Watch	LWX	6 hr
Aug 31, 11:56 PM CDT	Tornado Watch	SPC	6 hr
Sep 1, 2:23 AM CDT	Areal Flood Warning	LWX	8 hr
Sep 1, 2:24 AM CDT	Severe Thunderstorm Warning	LWX	51 min
Sep 1, 2:50 AM CDT	Areal Flood Warning	LWX	6 hr
Sep 1, 9:14 AM CDT	Coastal Flood Advisory	LWX	19 hr
Sep 1, 9:37 AM CDT	Areal Flood Warning	LWX	7 hr
Sep 1, 10:46 AM CDT	Tornado Watch	SPC	9 hr
Sep 3, 2:01 AM CDT	Coastal Flood Advisory	LWX	6 hr
Sep 3, 1:52 PM CDT	Coastal Flood Advisory	LWX	17 hr
Sep 5, 4:47 AM CDT	Coastal Flood Advisory	LWX	3 hr
Sep 8, 1:28 PM CDT	Coastal Flood Advisory	LWX	11 hr
Sep 8, 5:11 PM CDT	Flash Flood Watch	LWX	10 hr
Sep 8, 7:29 PM CDT	Severe Thunderstorm Watch	SPC	4 hr
Sep 16, 1:44 PM CDT	Flash Flood Watch	LWX	6 hr
Sep 16, 2:21 PM CDT	Areal Flood Warning	LWX	6 hr
Sep 16, 2:50 PM CDT	Flash Flood Warning Considerable damage threat	LWX	3 hr
Sep 20, 7:27 PM CDT	Coastal Flood Advisory	LWX	93 min
Sep 21, 2:04 AM CDT	Flash Flood Watch	LWX	57 hr
Sep 21, 2:11 AM CDT	Coastal Flood Advisory	LWX	20 hr
Sep 22, 2:14 AM CDT	Coastal Flood Advisory	LWX	46 hr
Sep 22, 8:39 AM CDT	Coastal Flood Warning	LWX	34 hr
Sep 23, 2:47 AM CDT	Areal Flood Warning	LWX	12 hr
Sep 23, 7:04 AM CDT	Areal Flood Warning	LWX	10 hr
Sep 24, 8:55 PM CDT	Coastal Flood Advisory	LWX	5 hr
Sep 25, 8:52 PM CDT	Coastal Flood Advisory	LWX	3 hr
Oct 6, 6:52 PM CDT	Coastal Flood Advisory	LWX	3 hr
Oct 7, 5:49 AM CDT	Coastal Flood Advisory	LWX	3 hr
Oct 7, 12:39 PM CDT	Coastal Flood Advisory	LWX	9 hr
Oct 8, 6:47 PM CDT	Coastal Flood Advisory	LWX	4 hr
Oct 9, 4:39 AM CDT	Coastal Flood Advisory	LWX	7 hr
Oct 9, 2:17 PM CDT	Coastal Flood Advisory	LWX	10 hr
Oct 10, 2:00 AM CDT	Coastal Flood Advisory	LWX	11 hr
Oct 10, 1:29 PM CDT	Coastal Flood Advisory	LWX	33 hr
Oct 11, 2:18 AM CDT	Coastal Flood Advisory	LWX	48 hr
Oct 12, 2:49 AM CDT	Coastal Flood Advisory	LWX	24 hr
Oct 13, 2:38 AM CDT	Coastal Flood Advisory	LWX	25 hr
Oct 14, 1:36 AM CDT	Dense Fog Advisory	LWX	7 hr
Oct 15, 2:11 PM CDT	Coastal Flood Advisory	LWX	30 hr
Oct 25, 4:50 PM CDT	Flash Flood Watch	LWX	5 hr
Oct 25, 7:32 PM CDT	Areal Flood Warning	LWX	7 hr
Oct 26, 1:55 AM CDT	Wind Advisory	LWX	21 hr
Oct 27, 9:50 AM CDT	Coastal Flood Watch	LWX	29 hr
Oct 28, 3:29 AM CDT	Coastal Flood Warning	LWX	72 hr
Oct 28, 3:29 AM CDT	Coastal Flood Advisory	LWX	12 hr
Oct 28, 1:07 PM CDT	Flood Watch	LWX	28 hr
Oct 29, 11:34 AM CDT	Areal Flood Warning	LWX	9 hr
Oct 30, 3:22 AM CDT	Coastal Flood Advisory	LWX	49 hr
Nov 2, 2:22 AM CDT	Frost Advisory	LWX	30 hr
Nov 3, 2:38 PM CDT	Frost Advisory	LWX	17 hr
Nov 4, 3:06 AM CDT	Frost Advisory	LWX	29 hr
Nov 4, 3:06 AM CDT	Freeze Warning	LWX	29 hr
Nov 6, 1:21 PM CDT	Coastal Flood Advisory	LWX	10 hr
Nov 8, 10:06 PM CST	Coastal Flood Advisory	LWX	54 min
Nov 9, 3:48 PM CST	Coastal Flood Advisory	LWX	9 hr
Nov 12, 1:07 AM CST	Coastal Flood Advisory	LWX	53 min
Nov 26, 12:48 PM CST	Wind Advisory	LWX	3 hr
Dec 6, 10:09 AM CST	Wind Advisory	LWX	14 hr
Dec 10, 9:48 AM CST	Wind Advisory	LWX	38 hr
Dec 29, 11:35 AM CST	Coastal Flood Advisory	LWX	5 hr
Dec 30, 1:47 PM CST	Coastal Flood Advisory	LWX	3 hr
Dec 31, 1:21 PM CST	Coastal Flood Advisory	LWX	5 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	35
Tornado Warning	2
Severe Thunderstorm Watch	13
Tornado Watch	3
Flooding
Areal Flood Warning	20
Flash Flood Warning	11
Flash Flood Watch	15
Flood Watch	1
Winter
Ice Storm Warning	1
Winter Storm Warning	3
Winter Storm Watch	4
Winter Weather Advisory	6
Heat
Excessive Heat Watch	1
Heat Advisory	4
Cold
Freeze Warning	1
Frost Advisory	4
Wind and dust
High Wind Warning	1
High Wind Watch	1
Wind Advisory	9
Fire
Red Flag Warning	2
Fire Weather Watch	2
Fog and smoke
Dense Fog Advisory	3
Coast and beach
Coastal Flood Warning	2
Coastal Flood Watch	1
Coastal Flood Advisory	67

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record The radar archive 2020 2022

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.