Alert archive / Colorado / Washington County

Weather alerts in Washington County, Colorado, 2019

200 weather alerts in 2019, 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 2019. Tap one for its archive.

Alerts: 200
Warnings: 61
Watches: 37
Advisories: 28
Busiest month: June45 alerts
Busiest day: August 11, 201912 alerts

Over time

By month

Warning verification

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

2 of 6 tornado warnings covering Washington County in 2019 had a tornado report inside them; 3 of 4 tornado reports fell inside a warning, on average 13 minutes after it went out.

Washington County, 2019

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	6	2	67%	4	75%	13 min
Severe thunderstorm warnings	33	11	67%	17	65%	13 min
Flash flood warnings	4	0	100%	0

Each office's whole area, 2019

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Denver/Boulder, CO: tornado warnings	32	11	66%	33	48%	11 min
NWS Denver/Boulder, CO: severe thunderstorm warnings	281	117	58%	382	77%	18 min
NWS Denver/Boulder, CO: flash flood warnings	15	2	87%	3	67%	58 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, Mountain Time. Each opens its own page with the text, the map, the radar and the sounding.

Issued	Product	Office	Lasted
Jan 6, 12:31 PM MST	High Wind Warning	BOU	33 hr
Jan 6, 8:09 PM MST	High Wind Watch	BOU	7 hr
Jan 20, 3:01 PM MST	Winter Storm Watch	BOU	20 hr
Jan 21, 11:18 AM MST	Blizzard Warning	BOU	24 hr
Jan 27, 9:05 PM MST	Special Weather Statement	BOU	40 min
Feb 5, 4:11 AM MST	Winter Weather Advisory	BOU	48 hr
Feb 7, 3:49 AM MST	Wind Chill Advisory	BOU	7 hr
Feb 20, 3:59 PM MST	Winter Weather Advisory	BOU	66 hr
Feb 21, 3:17 PM MST	Winter Storm Watch	BOU	19 hr
Feb 22, 8:54 PM MST	Winter Storm Warning	BOU	13 hr
Feb 28, 5:33 PM MST	Winter Weather Advisory	BOU	58 hr
Mar 2, 6:44 PM MST	Mesoscale Discussion	SPC	4 hr
Mar 3, 3:36 AM MST	Wind Chill Advisory	BOU	5 hr
Mar 3, 3:36 AM MST	Wind Chill Advisory	BOU	29 hr
Mar 11, 6:48 AM MDT	Winter Storm Watch	BOU	28 hr
Mar 11, 3:24 PM MDT	Blizzard Warning	BOU	68 hr
Mar 13, 10:27 AM MDT	Mesoscale Discussion	SPC	3 hr
Mar 13, 1:37 PM MDT	Mesoscale Discussion	SPC	4 hr
Mar 13, 5:26 PM MDT	Mesoscale Discussion	SPC	6 hr
Mar 14, 11:52 AM MDT	Winter Weather Advisory	BOU	6 hr
Apr 7, 3:05 PM MDT	Fire Weather Watch	BOU	21 hr
Apr 8, 12:03 PM MDT	Red Flag Warning	BOU	31 hr
Apr 8, 3:10 PM MDT	Winter Storm Watch	BOU	21 hr
Apr 9, 11:47 AM MDT	Blizzard Warning	BOU	47 hr
Apr 10, 8:31 PM MDT	Winter Weather Advisory	BOU	22 hr
Apr 21, 4:11 PM MDT	Special Weather Statement	BOU	49 min
Apr 26, 7:19 PM MDT	Special Weather Statement	BOU	56 min
Apr 26, 8:07 PM MDT	Special Weather Statement	BOU	38 min
Apr 28, 1:11 PM MDT	Mesoscale Discussion	SPC	2 hr
Apr 28, 2:51 PM MDT	Special Weather Statement	BOU	54 min
May 7, 1:01 AM MDT	Dense Fog Advisory	BOU	7 hr
May 7, 8:53 PM MDT	Dense Fog Advisory	BOU	12 hr
May 8, 3:50 PM MDT	Freeze Watch	BOU	24 hr
May 9, 4:03 PM MDT	Frost Advisory	BOU	16 hr
May 10, 2:51 PM MDT	Frost Advisory	BOU	18 hr
May 11, 5:45 PM MDT	Frost Advisory	BOU	14 hr
May 17, 12:54 PM MDT	Severe Thunderstorm Watch	SPC	6 hr
May 17, 4:07 PM MDT	Mesoscale Discussion	SPC	113 min
May 18, 2:49 PM MDT	Frost Advisory	BOU	17 hr
May 21, 12:01 PM MDT	Freeze Warning	BOU	19 hr
May 26, 3:46 PM MDT	Tornado Watch	SPC	4 hr
May 27, 12:36 PM MDT	Mesoscale Discussion	SPC	2 hr
May 27, 12:56 PM MDT	Tornado Watch	SPC	8 hr
May 27, 2:43 PM MDT	Mesoscale Discussion	SPC	2 hr
Jun 2, 12:11 PM MDT	Severe Thunderstorm Watch	SPC	8 hr
Jun 2, 5:24 PM MDT	Mesoscale Discussion	SPC	66 min
Jun 3, 1:31 PM MDT	Mesoscale Discussion	SPC	119 min
Jun 3, 1:53 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 3, 3:52 PM MDT	Special Weather Statement	BOU	23 min
Jun 3, 4:31 PM MDT	Special Weather Statement	BOU	29 min
Jun 3, 4:40 PM MDT	Severe Thunderstorm Warning	BOU	50 min
Jun 4, 12:59 PM MDT	Mesoscale Discussion	SPC	2 hr
Jun 7, 6:07 PM MDT	Severe Thunderstorm Warning	BOU	38 min
Jun 7, 6:31 PM MDT	Severe Thunderstorm Warning	BOU	29 min
Jun 7, 6:41 PM MDT	Severe Thunderstorm Warning	BOU	34 min
Jun 7, 7:03 PM MDT	Severe Thunderstorm Warning	BOU	42 min
Jun 7, 7:13 PM MDT	Severe Thunderstorm Warning	BOU	47 min
Jun 7, 7:47 PM MDT	Severe Thunderstorm Warning	BOU	20 min
Jun 7, 8:01 PM MDT	Severe Thunderstorm Warning	BOU	19 min
Jun 8, 1:18 PM MDT	Mesoscale Discussion	SPC	87 min
Jun 8, 3:44 PM MDT	Mesoscale Discussion	SPC	61 min
Jun 8, 3:44 PM MDT	Severe Thunderstorm Watch	SPC	5 hr
Jun 8, 6:19 PM MDT	Mesoscale Discussion	SPC	86 min
Jun 8, 6:28 PM MDT	Severe Thunderstorm Warning	BOU	32 min
Jun 8, 8:09 PM MDT	Mesoscale Discussion	SPC	96 min
Jun 13, 5:51 PM MDT	Special Weather Statement	BOU	39 min
Jun 13, 5:58 PM MDT	Mesoscale Discussion	SPC	92 min
Jun 14, 12:44 PM MDT	Mesoscale Discussion	SPC	3 hr
Jun 14, 1:49 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 17, 12:04 PM MDT	Mesoscale Discussion	SPC	86 min
Jun 17, 3:59 PM MDT	Severe Thunderstorm Warning	BOU	46 min
Jun 17, 4:00 PM MDT	Severe Thunderstorm Warning	BOU	45 min
Jun 17, 4:11 PM MDT	Flash Flood Warning	BOU	3 hr
Jun 17, 4:30 PM MDT	Mesoscale Discussion	SPC	90 min
Jun 17, 4:45 PM MDT	Severe Thunderstorm Warning	BOU	45 min
Jun 17, 5:28 PM MDT	Areal Flood Advisory	BOU	92 min
Jun 17, 5:28 PM MDT	Areal Flood Advisory	BOU	92 min
Jun 17, 5:59 PM MDT	Areal Flood Advisory	BOU	2 hr
Jun 20, 2:51 PM MDT	Mesoscale Discussion	SPC	114 min
Jun 20, 4:04 PM MDT	Tornado Watch	SPC	6 hr
Jun 20, 4:56 PM MDT	Severe Thunderstorm Warning	BOU	49 min
Jun 20, 5:13 PM MDT	Severe Thunderstorm Warning	BOU	32 min
Jun 20, 5:44 PM MDT	Special Weather Statement	BOU	46 min
Jun 20, 6:21 PM MDT	Severe Thunderstorm Warning	BOU	24 min
Jun 20, 6:43 PM MDT	Severe Thunderstorm Warning	BOU	32 min
Jun 23, 12:41 PM MDT	Mesoscale Discussion	SPC	2 hr
Jun 26, 2:36 PM MDT	Mesoscale Discussion	SPC	2 hr
Jun 26, 4:37 PM MDT	Severe Thunderstorm Watch	SPC	6 hr
Jun 30, 5:59 PM MDT	Severe Thunderstorm Warning	BOU	31 min
Jul 4, 2:10 PM MDT	Mesoscale Discussion	SPC	2 hr
Jul 4, 3:01 PM MDT	Tornado Watch	SPC	7 hr
Jul 4, 5:40 PM MDT	Mesoscale Discussion	SPC	95 min
Jul 4, 7:31 PM MDT	Severe Thunderstorm Warning	BOU	44 min
Jul 4, 7:33 PM MDT	Special Weather Statement	GLD	27 min
Jul 4, 7:50 PM MDT	Severe Thunderstorm Warning	BOU	25 min
Jul 4, 8:18 PM MDT	Severe Thunderstorm Warning	BOU	27 min
Jul 4, 8:44 PM MDT	Mesoscale Discussion	SPC	76 min
Jul 4, 8:53 PM MDT	Severe Thunderstorm Warning	BOU	37 min
Jul 4, 9:08 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 4, 9:41 PM MDT	Severe Thunderstorm Warning	BOU	49 min
Jul 5, 12:43 AM MDT	Mesoscale Discussion	SPC	2 hr
Jul 5, 1:18 PM MDT	Mesoscale Discussion	SPC	117 min
Jul 5, 3:36 PM MDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 5, 6:01 PM MDT	Mesoscale Discussion	SPC	89 min
Jul 5, 9:18 PM MDT	Mesoscale Discussion	SPC	57 min
Jul 6, 12:25 PM MDT	Mesoscale Discussion	SPC	95 min
Jul 6, 12:42 PM MDT	Severe Thunderstorm Watch	SPC	10 hr
Jul 6, 4:55 PM MDT	Mesoscale Discussion	SPC	95 min
Jul 6, 8:06 PM MDT	Mesoscale Discussion	SPC	84 min
Jul 7, 2:14 PM MDT	Mesoscale Discussion	SPC	3 hr
Jul 8, 1:26 PM MDT	Mesoscale Discussion	SPC	3 hr
Jul 8, 3:24 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 8, 3:37 PM MDT	Areal Flood Advisory	BOU	2 hr
Jul 8, 4:04 PM MDT	Flash Flood Warning	BOU	3 hr
Jul 8, 5:50 PM MDT	Mesoscale Discussion	SPC	115 min
Jul 8, 6:57 PM MDT	Areal Flood Warning	BOU	3 hr
Jul 14, 3:48 PM MDT	Areal Flood Advisory	BOU	87 min
Jul 14, 4:19 PM MDT	Flash Flood Warning	BOU	2 hr
Jul 14, 6:07 PM MDT	Flash Flood Warning	BOU	83 min
Jul 15, 7:37 PM MDT	Special Weather Statement	BOU	53 min
Jul 15, 7:49 PM MDT	Severe Thunderstorm Warning	BOU	41 min
Jul 20, 2:29 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 20, 5:43 PM MDT	Mesoscale Discussion	SPC	92 min
Jul 21, 4:37 PM MDT	Mesoscale Discussion	SPC	83 min
Jul 27, 7:42 PM MDT	Special Weather Statement	GLD	48 min
Jul 29, 1:52 PM MDT	Mesoscale Discussion	SPC	113 min
Aug 1, 3:14 AM MDT	Flash Flood Watch	BOU	20 hr
Aug 1, 1:25 PM MDT	Mesoscale Discussion	SPC	95 min
Aug 1, 1:55 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Aug 1, 4:37 PM MDT	Mesoscale Discussion	SPC	83 min
Aug 1, 5:19 PM MDT	Severe Thunderstorm Warning	BOU	26 min
Aug 1, 5:42 PM MDT	Areal Flood Advisory	BOU	2 hr
Aug 1, 6:21 PM MDT	Severe Thunderstorm Warning	BOU	24 min
Aug 11, 12:54 PM MDT	Mesoscale Discussion	SPC	2 hr
Aug 11, 1:24 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Aug 11, 2:45 PM MDT	Severe Thunderstorm Warning	BOU	30 min
Aug 11, 3:07 PM MDT	Tornado Warning	BOU	38 min
Aug 11, 3:30 PM MDT	Severe Thunderstorm Warning	BOU	30 min
Aug 11, 3:35 PM MDT	Tornado Warning	BOU	25 min
Aug 11, 3:36 PM MDT	Areal Flood Advisory	BOU	51 min
Aug 11, 3:40 PM MDT	Tornado Warning	BOU	35 min
Aug 11, 3:54 PM MDT	Severe Thunderstorm Warning	BOU	36 min
Aug 11, 3:59 PM MDT	Severe Thunderstorm Warning	BOU	31 min
Aug 11, 4:10 PM MDT	Tornado Warning Tornado observed	BOU	20 min
Aug 11, 4:51 PM MDT	Mesoscale Discussion	SPC	114 min
Aug 11, 6:13 PM MDT	Mesoscale Discussion	SPC	2 hr
Aug 13, 11:32 AM MDT	Mesoscale Discussion	SPC	118 min
Aug 13, 11:49 AM MDT	Tornado Watch	SPC	7 hr
Aug 14, 2:13 AM MDT	Special Weather Statement	BOU	47 min
Aug 14, 1:54 PM MDT	Mesoscale Discussion	SPC	2 hr
Aug 14, 3:00 PM MDT	Severe Thunderstorm Watch	SPC	6 hr
Aug 14, 5:58 PM MDT	Mesoscale Discussion	SPC	92 min
Aug 16, 1:40 PM MDT	Mesoscale Discussion	SPC	65 min
Aug 16, 2:54 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Aug 16, 5:06 PM MDT	Severe Thunderstorm Warning	BOU	39 min
Aug 16, 5:27 PM MDT	Mesoscale Discussion	SPC	2 hr
Aug 16, 5:33 PM MDT	Tornado Warning	BOU	27 min
Aug 16, 5:33 PM MDT	Tornado Warning	BOU	27 min
Aug 16, 7:18 PM MDT	Severe Thunderstorm Warning	BOU	42 min
Aug 16, 7:43 PM MDT	Mesoscale Discussion	SPC	2 hr
Aug 17, 1:34 PM MDT	Mesoscale Discussion	SPC	116 min
Aug 17, 5:28 PM MDT	Mesoscale Discussion	SPC	2 hr
Aug 22, 2:11 PM MDT	Mesoscale Discussion	SPC	94 min
Aug 23, 1:55 PM MDT	Mesoscale Discussion	SPC	110 min
Aug 23, 2:34 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Aug 23, 4:28 PM MDT	Mesoscale Discussion	SPC	2 hr
Aug 23, 6:26 PM MDT	Special Weather Statement	BOU	34 min
Aug 30, 11:31 PM MDT	Severe Thunderstorm Warning	BOU	44 min
Sep 8, 2:40 PM MDT	Mesoscale Discussion	SPC	95 min
Sep 8, 2:56 PM MDT	Severe Thunderstorm Watch	SPC	6 hr
Sep 8, 6:34 PM MDT	Severe Thunderstorm Warning	BOU	41 min
Sep 8, 6:39 PM MDT	Mesoscale Discussion	SPC	81 min
Sep 11, 1:28 PM MDT	Mesoscale Discussion	SPC	92 min
Sep 11, 2:31 PM MDT	Severe Thunderstorm Watch	SPC	10 hr
Sep 27, 3:02 PM MDT	Fire Weather Watch	BOU	13 hr
Sep 27, 3:02 PM MDT	Fire Weather Watch	BOU	37 hr
Sep 28, 4:15 AM MDT	Red Flag Warning	BOU	39 hr
Sep 29, 3:56 AM MDT	Red Flag Warning	BOU	39 hr
Oct 2, 2:26 AM MDT	Frost Advisory	BOU	30 hr
Oct 6, 3:37 AM MDT	Frost Advisory	BOU	28 hr
Oct 8, 3:06 PM MDT	Freeze Watch	BOU	13 hr
Oct 9, 4:18 AM MDT	Freeze Warning	BOU	29 hr
Oct 20, 2:49 AM MDT	High Wind Warning	BOU	16 hr
Oct 28, 5:17 AM MDT	Mesoscale Discussion	SPC	3 hr
Oct 28, 2:26 PM MDT	Winter Storm Warning	BOU	37 hr
Nov 24, 4:38 AM MST	Winter Storm Watch	BOU	9 hr
Nov 24, 1:40 PM MST	Winter Storm Warning	BOU	51 hr
Nov 24, 1:40 PM MST	Winter Weather Advisory	BOU	51 hr
Nov 26, 1:34 AM MST	Mesoscale Discussion	SPC	5 hr
Nov 26, 4:16 AM MST	Blizzard Warning	BOU	8 hr
Nov 26, 9:58 AM MST	Mesoscale Discussion	SPC	6 hr
Nov 28, 3:00 AM MST	High Wind Watch	BOU	24 hr
Nov 29, 1:44 AM MST	Dense Fog Advisory	BOU	9 hr
Nov 29, 2:55 AM MST	Winter Weather Advisory	BOU	48 hr
Nov 29, 3:02 AM MST	High Wind Warning	BOU	39 hr
Nov 29, 5:39 PM MST	Dense Fog Advisory	BOU	6 hr
Dec 6, 3:20 AM MST	Dense Fog Advisory	BOU	6 hr
Dec 14, 2:35 PM MST	Snow Squall Warning	BOU	55 min
Dec 26, 3:36 AM MST	Winter Storm Watch	BOU	34 hr
Dec 27, 1:57 PM MST	Winter Storm Warning	BOU	34 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	33
Tornado Warning	6
Severe Thunderstorm Watch	18
Tornado Watch	5
Mesoscale Discussion	60
Special Weather Statement	14
Flooding
Areal Flood Warning	1
Flash Flood Warning	4
Flash Flood Watch	1
Areal Flood Advisory	7
Winter
Blizzard Warning	4
Snow Squall Warning	1
Winter Storm Warning	4
Winter Storm Watch	6
Winter Weather Advisory	7
Cold
Freeze Warning	2
Freeze Watch	2
Frost Advisory	6
Wind Chill Advisory	3
Wind and dust
High Wind Warning	3
High Wind Watch	2
Fire
Red Flag Warning	3
Fire Weather Watch	3
Fog and smoke
Dense Fog Advisory	5

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.