Alert archive / Virginia / Fairfax County

Weather alerts in Fairfax County, Virginia, 2019

234 weather alerts in 2019, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Fairfax County and its neighbors

Each county as a circle sized by its count in 2019. Tap one for its archive.

Alerts: 234
Warnings: 117
Watches: 34
Advisories: 30
Busiest month: July58 alerts
Busiest day: August 20, 201913 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 Fairfax County in 2019 had a tornado report inside them; 1 of 1 tornado reports fell inside a warning, on average 6 minutes after it went out.

Fairfax County, 2019

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	2	1	50%	1	100%	6 min
Severe thunderstorm warnings	86	70	19%	106	95%	17 min
Flash flood warnings	3	3	0%	24	100%	136 min

Each office's whole area, 2019

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Baltimore/Washington: tornado warnings	34	4	88%	8	50%	5 min
NWS Baltimore/Washington: severe thunderstorm warnings	694	468	33%	1,610	81%	19 min
NWS Baltimore/Washington: flash flood warnings	36	16	56%	74	96%	103 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
Jan 11, 2:17 PM EST	Winter Storm Warning	LWX	56 hr
Jan 11, 2:17 PM EST	Winter Weather Advisory	LWX	56 hr
Jan 13, 3:54 AM EST	Mesoscale Discussion	SPC	4 hr
Jan 13, 6:19 PM EST	Special Weather Statement	LWX	116 min
Jan 13, 9:47 PM EST	Winter Weather Advisory	LWX	20 hr
Jan 17, 3:41 AM EST	Winter Weather Advisory	LWX	30 hr
Jan 18, 8:31 AM EST	Dense Fog Advisory	LWX	3 hr
Jan 19, 1:44 PM EST	Wind Advisory	LWX	29 hr
Jan 20, 3:44 AM EST	Wind Chill Advisory	LWX	31 hr
Jan 20, 8:23 AM EST	Areal Flood Warning	LWX	6 hr
Jan 21, 8:55 AM EST	Wind Advisory	LWX	4 hr
Jan 23, 4:03 AM EST	Flood Watch	LWX	35 hr
Jan 23, 12:54 PM EST	Wind Advisory	LWX	21 hr
Jan 24, 11:36 AM EST	Areal Flood Warning	LWX	6 hr
Jan 24, 2:08 PM EST	Areal Flood Warning	LWX	15 hr
Jan 28, 2:58 PM EST	Winter Weather Advisory	LWX	29 hr
Jan 29, 9:00 PM EST	Wind Advisory	LWX	20 hr
Jan 30, 3:33 AM EST	Wind Chill Advisory	LWX	30 hr
Jan 31, 3:27 PM EST	Winter Weather Advisory	LWX	27 hr
Feb 7, 8:32 PM EST	Dense Fog Advisory	LWX	8 hr
Feb 10, 3:02 AM EST	Winter Weather Advisory	LWX	61 hr
Feb 18, 3:38 AM EST	Winter Storm Watch	LWX	23 hr
Feb 19, 2:47 AM EST	Winter Storm Warning	LWX	46 hr
Feb 19, 2:47 AM EST	Winter Weather Advisory	LWX	46 hr
Feb 23, 3:01 PM EST	High Wind Warning	LWX	44 hr
Feb 23, 3:01 PM EST	Wind Advisory	LWX	44 hr
Feb 24, 3:02 AM EST	Wind Advisory	LWX	38 hr
Feb 28, 9:28 AM EST	Winter Weather Advisory	LWX	24 hr
Mar 19, 10:00 AM EDT	Special Weather Statement	LWX	15 min
Mar 20, 8:53 PM EDT	Flood Watch	LWX	26 hr
Mar 21, 4:01 PM EDT	Areal Flood Warning	LWX	24 hr
Mar 21, 6:29 PM EDT	Areal Flood Warning	LWX	8 hr
Mar 22, 3:26 PM EDT	Severe Thunderstorm Warning	LWX	49 min
Mar 22, 3:52 PM EDT	Severe Thunderstorm Warning	LWX	38 min
Apr 3, 3:56 AM EDT	Red Flag Warning	LWX	16 hr
Apr 14, 5:49 PM EDT	Mesoscale Discussion	SPC	26 min
Apr 14, 6:08 PM EDT	Tornado Watch	SPC	9 hr
Apr 14, 7:42 PM EDT	Mesoscale Discussion	SPC	63 min
Apr 15, 1:18 AM EDT	Severe Thunderstorm Warning	LWX	42 min
Apr 15, 1:43 AM EDT	Severe Thunderstorm Warning	LWX	36 min
Apr 15, 2:05 AM EDT	Severe Thunderstorm Warning	LWX	14 min
Apr 15, 3:51 AM EDT	Wind Advisory	LWX	16 hr
Apr 18, 2:07 PM EDT	Flash Flood Watch	LWX	32 hr
Apr 19, 12:08 PM EDT	Mesoscale Discussion	SPC	2 hr
Apr 19, 12:48 PM EDT	Tornado Watch	SPC	9 hr
Apr 19, 4:32 PM EDT	Mesoscale Discussion	SPC	58 min
Apr 19, 6:21 PM EDT	Mesoscale Discussion	SPC	84 min
Apr 19, 8:41 PM EDT	Severe Thunderstorm Warning	LWX	34 min
Apr 19, 8:53 PM EDT	Tornado Warning	LWX	22 min
Apr 26, 11:37 AM EDT	Mesoscale Discussion	SPC	113 min
Apr 26, 1:33 PM EDT	Tornado Watch	SPC	6 hr
Apr 26, 2:20 PM EDT	Severe Thunderstorm Warning	LWX	40 min
Apr 26, 2:25 PM EDT	Severe Thunderstorm Warning	LWX	50 min
Apr 26, 2:39 PM EDT	Tornado Warning	LWX	19 min
Apr 26, 2:56 PM EDT	Severe Thunderstorm Warning	LWX	49 min
Apr 26, 5:39 PM EDT	Wind Advisory	LWX	19 hr
May 2, 4:30 AM EDT	Dense Fog Advisory	LWX	4 hr
May 2, 3:03 PM EDT	Severe Thunderstorm Warning	LWX	42 min
May 2, 3:28 PM EDT	Mesoscale Discussion	SPC	2 hr
May 2, 3:38 PM EDT	Severe Thunderstorm Warning	LWX	52 min
May 4, 4:05 AM EDT	Flash Flood Watch	LWX	30 hr
May 4, 11:10 PM EDT	Areal Flood Warning	LWX	6 hr
May 5, 10:02 PM EDT	Areal Flood Warning	LWX	6 hr
May 23, 1:02 PM EDT	Severe Thunderstorm Watch	SPC	5 hr
May 23, 3:11 PM EDT	Severe Thunderstorm Warning	LWX	34 min
May 23, 3:36 PM EDT	Severe Thunderstorm Warning	LWX	39 min
May 23, 3:42 PM EDT	Mesoscale Discussion	SPC	93 min
May 25, 5:43 PM EDT	Mesoscale Discussion	SPC	62 min
May 26, 11:14 AM EDT	Mesoscale Discussion	SPC	3 hr
May 26, 1:45 PM EDT	Mesoscale Discussion	SPC	2 hr
May 26, 5:45 PM EDT	Mesoscale Discussion	SPC	2 hr
May 26, 8:32 PM EDT	Severe Thunderstorm Watch	SPC	4 hr
May 26, 10:26 PM EDT	Mesoscale Discussion	SPC	94 min
May 30, 12:15 PM EDT	Mesoscale Discussion	SPC	2 hr
May 30, 2:01 PM EDT	Severe Thunderstorm Watch	SPC	5 hr
May 30, 2:32 PM EDT	Severe Thunderstorm Warning	LWX	43 min
May 30, 3:10 PM EDT	Severe Thunderstorm Warning	LWX	50 min
May 30, 3:42 PM EDT	Severe Thunderstorm Warning	LWX	48 min
May 30, 3:56 PM EDT	Mesoscale Discussion	SPC	64 min
May 30, 4:03 PM EDT	Severe Thunderstorm Warning	LWX	27 min
Jun 2, 12:53 PM EDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 2, 3:33 PM EDT	Mesoscale Discussion	SPC	87 min
Jun 2, 4:40 PM EDT	Severe Thunderstorm Warning	LWX	50 min
Jun 2, 5:13 PM EDT	Severe Thunderstorm Warning	LWX	26 min
Jun 2, 5:21 PM EDT	Severe Thunderstorm Warning	LWX	39 min
Jun 2, 5:25 PM EDT	Severe Thunderstorm Warning	LWX	26 min
Jun 2, 5:37 PM EDT	Severe Thunderstorm Warning	LWX	38 min
Jun 2, 5:52 PM EDT	Severe Thunderstorm Warning	LWX	23 min
Jun 2, 5:57 PM EDT	Mesoscale Discussion	SPC	93 min
Jun 2, 6:27 PM EDT	Severe Thunderstorm Warning	LWX	36 min
Jun 13, 3:51 PM EDT	Mesoscale Discussion	SPC	114 min
Jun 13, 4:47 PM EDT	Severe Thunderstorm Warning	LWX	43 min
Jun 13, 5:04 PM EDT	Severe Thunderstorm Warning	LWX	41 min
Jun 16, 1:53 PM EDT	Mesoscale Discussion	SPC	97 min
Jun 17, 3:57 AM EDT	Flash Flood Watch	LWX	15 hr
Jun 17, 2:03 PM EDT	Mesoscale Discussion	SPC	117 min
Jun 17, 4:05 PM EDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 17, 7:11 PM EDT	Severe Thunderstorm Warning	LWX	34 min
Jun 18, 3:38 AM EDT	Flash Flood Watch	LWX	19 hr
Jun 18, 12:23 PM EDT	Mesoscale Discussion	SPC	97 min
Jun 18, 2:11 PM EDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 18, 4:47 PM EDT	Mesoscale Discussion	SPC	88 min
Jun 20, 12:23 PM EDT	Mesoscale Discussion	SPC	2 hr
Jun 24, 7:17 PM EDT	Mesoscale Discussion	SPC	2 hr
Jun 27, 4:42 PM EDT	Severe Thunderstorm Warning	LWX	48 min
Jun 27, 5:12 PM EDT	Severe Thunderstorm Warning	LWX	48 min
Jun 27, 5:15 PM EDT	Areal Flood Warning	LWX	6 hr
Jun 27, 5:36 PM EDT	Severe Thunderstorm Warning	LWX	39 min
Jun 27, 6:15 PM EDT	Severe Thunderstorm Warning	LWX	45 min
Jun 27, 6:54 PM EDT	Areal Flood Warning	LWX	4 hr
Jun 28, 5:59 PM EDT	Mesoscale Discussion	SPC	2 hr
Jun 29, 2:04 PM EDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 29, 4:05 PM EDT	Severe Thunderstorm Warning	LWX	33 min
Jun 29, 4:45 PM EDT	Severe Thunderstorm Warning	LWX	45 min
Jul 2, 4:38 PM EDT	Severe Thunderstorm Warning	LWX	37 min
Jul 2, 5:53 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 2, 6:29 PM EDT	Severe Thunderstorm Warning	LWX	25 min
Jul 2, 6:31 PM EDT	Severe Thunderstorm Warning	LWX	33 min
Jul 2, 7:41 PM EDT	Severe Thunderstorm Warning	LWX	34 min
Jul 2, 8:20 PM EDT	Severe Thunderstorm Warning	LWX	25 min
Jul 4, 11:23 AM EDT	Flash Flood Watch	LWX	12 hr
Jul 4, 12:49 PM EDT	Mesoscale Discussion	SPC	116 min
Jul 4, 2:56 PM EDT	Severe Thunderstorm Warning	LWX	49 min
Jul 4, 4:29 PM EDT	Severe Thunderstorm Warning	LWX	33 min
Jul 6, 1:48 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 6, 6:25 PM EDT	Severe Thunderstorm Warning	LWX	35 min
Jul 6, 6:45 PM EDT	Severe Thunderstorm Warning	LWX	60 min
Jul 7, 4:06 AM EDT	Flash Flood Watch	LWX	34 hr
Jul 8, 7:46 AM EDT	Flash Flood Warning	LWX	5 hr
Jul 8, 8:20 AM EDT	Flash Flood Warning	LWX	5 hr
Jul 8, 9:21 AM EDT	Flash Flood Warning Emergency	LWX	114 min
Jul 8, 12:53 PM EDT	Areal Flood Warning	LWX	5 hr
Jul 11, 4:18 AM EDT	Flash Flood Watch	LWX	15 hr
Jul 11, 12:51 PM EDT	Mesoscale Discussion	SPC	84 min
Jul 11, 5:14 PM EDT	Severe Thunderstorm Warning	LWX	46 min
Jul 11, 5:59 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 11, 6:13 PM EDT	Areal Flood Warning	LWX	3 hr
Jul 16, 3:28 PM EDT	Mesoscale Discussion	SPC	3 hr
Jul 16, 8:49 PM EDT	Heat Advisory	LWX	22 hr
Jul 17, 1:29 PM EDT	Mesoscale Discussion	SPC	3 hr
Jul 17, 4:43 PM EDT	Severe Thunderstorm Warning	LWX	47 min
Jul 17, 4:48 PM EDT	Severe Thunderstorm Warning	LWX	42 min
Jul 17, 4:51 PM EDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 17, 5:08 PM EDT	Severe Thunderstorm Warning	LWX	41 min
Jul 17, 5:23 PM EDT	Severe Thunderstorm Warning	LWX	52 min
Jul 17, 5:35 PM EDT	Severe Thunderstorm Warning	LWX	40 min
Jul 17, 8:57 PM EDT	Excessive Heat Watch	LWX	6 hr
Jul 17, 8:57 PM EDT	Excessive Heat Watch	LWX	19 hr
Jul 18, 11:09 AM EDT	Excessive Heat Watch	LWX	28 hr
Jul 18, 11:09 AM EDT	Excessive Heat Watch	LWX	58 hr
Jul 18, 1:49 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 18, 3:43 PM EDT	Heat Advisory	LWX	29 hr
Jul 19, 3:52 AM EDT	Excessive Heat Warning	LWX	17 hr
Jul 19, 3:05 PM EDT	Excessive Heat Warning	LWX	30 hr
Jul 20, 8:49 PM EDT	Excessive Heat Warning	LWX	24 hr
Jul 20, 9:18 PM EDT	Severe Thunderstorm Warning	LWX	30 min
Jul 21, 2:48 PM EDT	Flash Flood Watch	LWX	37 hr
Jul 21, 6:07 PM EDT	Mesoscale Discussion	SPC	83 min
Jul 21, 7:00 PM EDT	Severe Thunderstorm Warning	LWX	45 min
Jul 21, 7:32 PM EDT	Severe Thunderstorm Warning	LWX	43 min
Jul 21, 7:35 PM EDT	Severe Thunderstorm Warning	LWX	26 min
Jul 22, 1:11 PM EDT	Mesoscale Discussion	SPC	94 min
Jul 22, 2:17 PM EDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 22, 2:44 PM EDT	Severe Thunderstorm Warning	LWX	46 min
Jul 22, 7:20 PM EDT	Mesoscale Discussion	SPC	55 min
Jul 22, 7:43 PM EDT	Severe Thunderstorm Warning	LWX	47 min
Jul 22, 8:15 PM EDT	Severe Thunderstorm Warning	LWX	30 min
Jul 22, 8:21 PM EDT	Severe Thunderstorm Warning	LWX	24 min
Jul 22, 8:51 PM EDT	Mesoscale Discussion	SPC	84 min
Jul 31, 12:02 PM EDT	Flash Flood Watch	LWX	7 hr
Jul 31, 1:17 PM EDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 31, 4:19 PM EDT	Mesoscale Discussion	SPC	56 min
Aug 6, 6:21 PM EDT	Severe Thunderstorm Warning	LWX	39 min
Aug 6, 6:36 PM EDT	Severe Thunderstorm Warning	LWX	39 min
Aug 6, 6:56 PM EDT	Severe Thunderstorm Warning	LWX	49 min
Aug 6, 7:02 PM EDT	Areal Flood Warning	LWX	5 hr
Aug 6, 7:22 PM EDT	Severe Thunderstorm Warning	LWX	53 min
Aug 6, 7:42 PM EDT	Severe Thunderstorm Warning	LWX	33 min
Aug 6, 8:07 PM EDT	Areal Flood Warning	LWX	4 hr
Aug 6, 8:16 PM EDT	Severe Thunderstorm Warning	LWX	22 min
Aug 7, 1:02 PM EDT	Mesoscale Discussion	SPC	88 min
Aug 7, 1:53 PM EDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 7, 1:57 PM EDT	Severe Thunderstorm Warning	LWX	48 min
Aug 7, 2:41 PM EDT	Severe Thunderstorm Warning	LWX	38 min
Aug 7, 3:24 PM EDT	Severe Thunderstorm Warning	LWX	51 min
Aug 7, 3:52 PM EDT	Severe Thunderstorm Warning	LWX	38 min
Aug 7, 3:57 PM EDT	Mesoscale Discussion	SPC	93 min
Aug 7, 4:12 PM EDT	Severe Thunderstorm Warning	LWX	48 min
Aug 9, 2:25 PM EDT	Mesoscale Discussion	SPC	95 min
Aug 13, 8:58 PM EDT	Severe Thunderstorm Warning	LWX	32 min
Aug 15, 1:15 PM EDT	Mesoscale Discussion	SPC	2 hr
Aug 15, 2:38 PM EDT	Severe Thunderstorm Warning	LWX	52 min
Aug 15, 3:16 PM EDT	Severe Thunderstorm Warning	LWX	44 min
Aug 15, 3:48 PM EDT	Areal Flood Warning	LWX	2 hr
Aug 15, 4:23 PM EDT	Areal Flood Warning	LWX	2 hr
Aug 19, 10:34 PM EDT	Severe Thunderstorm Warning	LWX	41 min
Aug 19, 10:47 PM EDT	Severe Thunderstorm Warning	LWX	43 min
Aug 19, 11:06 PM EDT	Severe Thunderstorm Warning	LWX	15 min
Aug 20, 2:19 PM EDT	Mesoscale Discussion	SPC	56 min
Aug 20, 3:02 PM EDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 20, 4:34 PM EDT	Severe Thunderstorm Warning	LWX	41 min
Aug 20, 4:44 PM EDT	Severe Thunderstorm Warning	LWX	46 min
Aug 20, 5:10 PM EDT	Severe Thunderstorm Warning	LWX	20 min
Aug 20, 5:28 PM EDT	Severe Thunderstorm Warning	LWX	30 min
Aug 20, 5:33 PM EDT	Severe Thunderstorm Warning	LWX	27 min
Aug 20, 5:43 PM EDT	Severe Thunderstorm Warning	LWX	32 min
Aug 20, 6:12 PM EDT	Severe Thunderstorm Warning	LWX	48 min
Aug 20, 7:00 PM EDT	Mesoscale Discussion	SPC	2 hr
Aug 21, 3:27 PM EDT	Severe Thunderstorm Watch	SPC	4 hr
Sep 2, 4:53 PM EDT	Severe Thunderstorm Warning	LWX	37 min
Sep 2, 6:13 PM EDT	Severe Thunderstorm Warning	LWX	28 min
Sep 2, 6:26 PM EDT	Severe Thunderstorm Warning	LWX	49 min
Sep 11, 3:08 PM EDT	Mesoscale Discussion	SPC	2 hr
Sep 11, 4:57 PM EDT	Severe Thunderstorm Warning	LWX	48 min
Sep 12, 2:02 PM EDT	Mesoscale Discussion	SPC	118 min
Sep 28, 5:51 PM EDT	Mesoscale Discussion	SPC	114 min
Oct 16, 3:51 AM EDT	Wind Advisory	LWX	34 hr
Oct 18, 3:15 AM EDT	Frost Advisory	LWX	30 hr
Oct 22, 11:46 PM EDT	Dense Fog Advisory	LWX	6 hr
Oct 27, 11:45 AM EDT	Areal Flood Warning	LWX	100 min
Oct 31, 3:48 AM EDT	Wind Advisory	LWX	24 hr
Oct 31, 1:11 PM EDT	Mesoscale Discussion	SPC	3 hr
Oct 31, 2:56 PM EDT	Tornado Watch	SPC	10 hr
Oct 31, 4:01 PM EDT	Mesoscale Discussion	SPC	119 min
Oct 31, 7:14 PM EDT	Mesoscale Discussion	SPC	2 hr
Oct 31, 9:08 PM EDT	Severe Thunderstorm Warning	LWX	37 min
Oct 31, 10:07 PM EDT	Severe Thunderstorm Warning	LWX	38 min
Nov 1, 1:00 AM EDT	Areal Flood Warning	LWX	4 hr
Nov 1, 4:07 AM EDT	Freeze Watch	LWX	5 hr
Nov 1, 6:58 AM EDT	Areal Flood Warning	LWX	2 hr
Nov 1, 9:17 AM EDT	Freeze Warning	LWX	24 hr
Nov 26, 2:47 PM EST	Wind Advisory	LWX	45 hr
Dec 13, 4:59 PM EST	Dense Fog Advisory	LWX	6 hr
Dec 17, 11:47 AM EST	Dense Fog Advisory	LWX	3 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	86
Tornado Warning	2
Severe Thunderstorm Watch	13
Tornado Watch	4
Mesoscale Discussion	51
Special Weather Statement	2
Flooding
Areal Flood Warning	18
Flash Flood Warning	3
Flash Flood Watch	9
Flood Watch	2
Winter
Winter Storm Warning	2
Winter Storm Watch	1
Winter Weather Advisory	8
Heat
Excessive Heat Warning	3
Excessive Heat Watch	4
Heat Advisory	2
Cold
Freeze Warning	1
Freeze Watch	1
Frost Advisory	1
Wind Chill Advisory	2
Wind and dust
High Wind Warning	1
Wind Advisory	11
Fire
Red Flag Warning	1
Fog and smoke
Dense Fog Advisory	6

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2018 2020

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.