Alert archive / Colorado / Washington County

Weather alerts in Washington County, Colorado, 2015

177 weather alerts in 2015, 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 2015. Tap one for its archive.

Alerts: 177
Warnings: 62
Watches: 31
Advisories: 26
Busiest month: June44 alerts
Busiest day: June 5, 201511 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 11 tornado warnings covering Washington County in 2015 had a tornado report inside them; 3 of 4 tornado reports fell inside a warning, on average 7 minutes after it went out.

Washington County, 2015

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	11	2	82%	4	75%	7 min
Severe thunderstorm warnings	25	5	80%	3	67%	7 min
Flash flood warnings	1	1	0%	1	100%	61 min

Each office's whole area, 2015

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Denver/Boulder, CO: tornado warnings	59	12	80%	29	52%	13 min
NWS Denver/Boulder, CO: severe thunderstorm warnings	193	70	64%	208	67%	15 min
NWS Denver/Boulder, CO: flash flood warnings	33	5	85%	9	100%	37 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 2, 3:37 PM MST	Winter Weather Advisory	BOU	29 hr
Jan 3, 9:12 PM MST	Wind Chill Advisory	BOU	12 hr
Feb 19, 2:26 PM MST	Winter Storm Watch	BOU	22 hr
Feb 20, 4:25 AM MST	Winter Storm Warning	BOU	67 hr
Feb 20, 12:53 PM MST	Winter Weather Advisory	BOU	58 hr
Mar 16, 3:39 AM MDT	Red Flag Warning	BOU	14 hr
Mar 22, 2:56 PM MDT	Fire Weather Watch	BOU	24 hr
Mar 23, 2:40 PM MDT	Red Flag Warning	BOU	27 hr
Mar 30, 2:18 PM MDT	Red Flag Warning	BOU	5 hr
Apr 11, 2:39 PM MDT	Fire Weather Watch	BOU	7 hr
Apr 11, 9:10 PM MDT	Red Flag Warning	BOU	22 hr
Apr 13, 2:45 PM MDT	Red Flag Warning	BOU	29 hr
Apr 15, 1:41 PM MDT	Mesoscale Discussion	SPC	3 hr
Apr 17, 11:58 AM MDT	Mesoscale Discussion	SPC	92 min
Apr 17, 4:05 PM MDT	Mesoscale Discussion	SPC	2 hr
Apr 17, 4:27 PM MDT	Tornado Warning	BOU	18 min
Apr 17, 4:37 PM MDT	Tornado Watch	SPC	7 hr
Apr 17, 6:06 PM MDT	Mesoscale Discussion	SPC	84 min
Apr 17, 6:11 PM MDT	Tornado Warning	BOU	19 min
Apr 17, 7:56 PM MDT	Mesoscale Discussion	SPC	94 min
Apr 18, 1:38 PM MDT	Tornado Warning Tornado observed	BOU	22 min
Apr 18, 2:08 PM MDT	Tornado Watch	SPC	6 hr
Apr 23, 1:10 PM MDT	Mesoscale Discussion	SPC	95 min
May 5, 8:28 AM MDT	Dense Fog Advisory	BOU	4 hr
May 8, 11:08 AM MDT	Areal Flood Advisory	BOU	60 hr
May 8, 10:02 PM MDT	River Flood Warning	BOU	6 days
May 9, 5:10 AM MDT	Flash Flood Watch	BOU	15 hr
May 9, 5:15 AM MDT	Winter Storm Warning	BOU	25 hr
May 9, 9:09 AM MDT	Winter Storm Watch	BOU	4 hr
May 9, 10:52 AM MDT	Areal Flood Warning	BOU	9 hr
May 9, 11:55 AM MDT	Tornado Watch	SPC	11 hr
May 9, 2:34 PM MDT	Mesoscale Discussion	SPC	56 min
May 9, 5:16 PM MDT	Mesoscale Discussion	SPC	119 min
May 9, 7:49 PM MDT	Areal Flood Warning	BOU	18 hr
May 10, 5:26 AM MDT	Frost Advisory	BOU	26 hr
May 10, 5:56 AM MDT	Winter Storm Warning	BOU	3 hr
May 10, 1:04 PM MDT	Areal Flood Warning	BOU	24 hr
May 15, 12:58 PM MDT	Tornado Watch	SPC	7 hr
May 16, 3:17 PM MDT	Special Weather Statement	BOU	43 min
May 18, 7:53 PM MDT	River Flood Watch	BOU	30 hr
May 19, 6:52 AM MDT	Areal Flood Advisory	BOU	8 hr
May 19, 9:47 AM MDT	River Flood Warning	BOU	4 days
May 23, 5:41 AM MDT	Flash Flood Watch	BOU	18 hr
May 23, 12:27 PM MDT	Mesoscale Discussion	SPC	2 hr
May 23, 12:54 PM MDT	Tornado Watch	SPC	6 hr
May 23, 4:11 PM MDT	Mesoscale Discussion	SPC	2 hr
May 23, 6:27 PM MDT	River Flood Warning	BOU	72 hr
May 24, 4:44 AM MDT	Flash Flood Watch	BOU	14 hr
May 24, 12:22 PM MDT	Mesoscale Discussion	SPC	83 min
May 24, 2:17 PM MDT	Special Weather Statement	BOU	28 min
May 24, 2:43 PM MDT	Areal Flood Advisory	BOU	3 hr
May 24, 3:15 PM MDT	Special Weather Statement	BOU	30 min
May 27, 2:11 PM MDT	Severe Thunderstorm Warning	BOU	34 min
May 28, 12:39 PM MDT	Mesoscale Discussion	SPC	2 hr
May 28, 1:18 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
May 28, 3:15 PM MDT	Severe Thunderstorm Warning	BOU	45 min
May 28, 3:28 PM MDT	Severe Thunderstorm Warning	BOU	32 min
May 31, 2:50 PM MDT	Mesoscale Discussion	SPC	115 min
Jun 1, 9:48 PM MDT	Severe Thunderstorm Warning	BOU	27 min
Jun 1, 10:20 PM MDT	Areal Flood Advisory	BOU	3 hr
Jun 3, 12:34 PM MDT	Mesoscale Discussion	SPC	86 min
Jun 3, 7:14 PM MDT	Mesoscale Discussion	SPC	61 min
Jun 3, 8:59 PM MDT	Severe Thunderstorm Watch	SPC	5 hr
Jun 4, 1:53 PM MDT	Mesoscale Discussion	SPC	97 min
Jun 5, 2:21 AM MDT	Areal Flood Advisory	BOU	3 hr
Jun 5, 4:27 AM MDT	Flash Flood Watch	BOU	18 hr
Jun 5, 9:10 AM MDT	River Flood Warning	BOU	4 days
Jun 5, 12:49 PM MDT	Mesoscale Discussion	SPC	86 min
Jun 5, 1:09 PM MDT	Tornado Watch	SPC	6 hr
Jun 5, 3:41 PM MDT	Severe Thunderstorm Warning	BOU	49 min
Jun 5, 4:34 PM MDT	Severe Thunderstorm Warning	BOU	26 min
Jun 5, 4:36 PM MDT	Areal Flood Advisory	BOU	3 hr
Jun 5, 4:44 PM MDT	Tornado Warning	BOU	31 min
Jun 5, 4:58 PM MDT	Tornado Warning	BOU	32 min
Jun 5, 5:24 PM MDT	Severe Thunderstorm Warning	BOU	39 min
Jun 6, 2:14 PM MDT	Mesoscale Discussion	SPC	91 min
Jun 6, 3:48 PM MDT	Special Weather Statement	BOU	42 min
Jun 6, 3:59 PM MDT	Tornado Warning	BOU	31 min
Jun 6, 4:25 PM MDT	Severe Thunderstorm Watch	SPC	5 hr
Jun 6, 4:29 PM MDT	Tornado Warning	BOU	31 min
Jun 6, 6:55 PM MDT	Mesoscale Discussion	SPC	95 min
Jun 6, 9:33 PM MDT	Mesoscale Discussion	SPC	57 min
Jun 7, 10:00 AM MDT	River Flood Advisory	BOU	30 hr
Jun 7, 1:36 PM MDT	Mesoscale Discussion	SPC	114 min
Jun 8, 9:42 AM MDT	River Flood Warning	BOU	38 hr
Jun 10, 11:41 AM MDT	Flash Flood Watch	BOU	39 hr
Jun 11, 10:35 AM MDT	River Flood Warning	BOU	5 days
Jun 11, 5:27 PM MDT	Flash Flood Warning	BOU	4 hr
Jun 14, 3:36 PM MDT	Severe Thunderstorm Warning	BOU	39 min
Jun 15, 4:37 PM MDT	Areal Flood Warning	BOU	8 days
Jun 16, 2:44 PM MDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 16, 4:53 PM MDT	Mesoscale Discussion	SPC	97 min
Jun 16, 6:43 PM MDT	Severe Thunderstorm Warning	BOU	32 min
Jun 16, 7:29 PM MDT	Severe Thunderstorm Warning	BOU	46 min
Jun 16, 9:28 PM MDT	Mesoscale Discussion	SPC	62 min
Jun 23, 4:23 PM MDT	Areal Flood Warning	BOU	47 hr
Jun 23, 9:15 PM MDT	Severe Thunderstorm Warning	BOU	30 min
Jun 24, 2:34 PM MDT	Mesoscale Discussion	SPC	86 min
Jun 25, 2:10 PM MDT	Mesoscale Discussion	SPC	65 min
Jun 25, 2:30 PM MDT	Severe Thunderstorm Watch	SPC	8 hr
Jun 25, 4:25 PM MDT	Mesoscale Discussion	SPC	95 min
Jun 25, 5:22 PM MDT	Mesoscale Discussion	SPC	83 min
Jun 30, 11:01 PM MDT	Special Weather Statement	BOU	59 min
Jul 4, 6:11 PM MDT	Severe Thunderstorm Warning	BOU	49 min
Jul 14, 2:20 PM MDT	Mesoscale Discussion	SPC	85 min
Jul 18, 7:14 PM MDT	Special Weather Statement	GLD	16 min
Jul 18, 7:29 PM MDT	Special Weather Statement	GLD	31 min
Jul 19, 1:18 PM MDT	Mesoscale Discussion	SPC	117 min
Jul 19, 2:37 PM MDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 19, 6:06 PM MDT	Mesoscale Discussion	SPC	114 min
Jul 21, 3:50 PM MDT	Flash Flood Watch	BOU	4 hr
Jul 21, 4:28 PM MDT	Severe Thunderstorm Warning	BOU	34 min
Jul 26, 12:30 PM MDT	Mesoscale Discussion	SPC	2 hr
Jul 26, 1:07 PM MDT	Severe Thunderstorm Watch	SPC	9 hr
Jul 26, 1:12 PM MDT	Severe Thunderstorm Warning	BOU	48 min
Jul 26, 3:57 PM MDT	Areal Flood Advisory	BOU	2 hr
Jul 26, 4:22 PM MDT	Mesoscale Discussion	SPC	83 min
Jul 27, 3:57 PM MDT	Mesoscale Discussion	SPC	2 hr
Jul 30, 3:33 PM MDT	Areal Flood Advisory	BOU	117 min
Jul 30, 3:39 PM MDT	Special Weather Statement	BOU	36 min
Jul 30, 4:16 PM MDT	Special Weather Statement	BOU	29 min
Jul 30, 4:48 PM MDT	Areal Flood Advisory	BOU	117 min
Jul 30, 5:36 PM MDT	Special Weather Statement	BOU	24 min
Jul 30, 5:47 PM MDT	Areal Flood Advisory	BOU	118 min
Aug 1, 6:46 PM MDT	Severe Thunderstorm Warning	BOU	29 min
Aug 1, 7:23 PM MDT	Severe Thunderstorm Warning	BOU	22 min
Aug 1, 7:42 PM MDT	Severe Thunderstorm Warning	BOU	33 min
Aug 7, 2:12 PM MDT	Mesoscale Discussion	SPC	3 hr
Aug 7, 3:05 PM MDT	Severe Thunderstorm Watch	SPC	8 hr
Aug 7, 5:50 PM MDT	Tornado Warning	BOU	40 min
Aug 7, 5:55 PM MDT	Severe Thunderstorm Warning	BOU	50 min
Aug 7, 6:27 PM MDT	Mesoscale Discussion	SPC	2 hr
Aug 7, 6:33 PM MDT	Severe Thunderstorm Warning	BOU	42 min
Aug 7, 6:33 PM MDT	Tornado Warning	BOU	27 min
Aug 7, 6:49 PM MDT	Tornado Warning	BOU	26 min
Aug 7, 6:54 PM MDT	Tornado Warning	BOU	25 min
Aug 7, 7:22 PM MDT	Severe Thunderstorm Warning	BOU	38 min
Aug 7, 9:52 PM MDT	Areal Flood Advisory	BOU	3 hr
Aug 15, 4:40 PM MDT	Special Weather Statement	BOU	35 min
Aug 15, 5:09 PM MDT	Special Weather Statement	BOU	36 min
Aug 15, 5:14 PM MDT	Areal Flood Advisory	BOU	2 hr
Aug 15, 5:25 PM MDT	Areal Flood Advisory	BOU	2 hr
Aug 15, 6:28 PM MDT	Special Weather Statement	BOU	32 min
Aug 15, 6:47 PM MDT	Severe Thunderstorm Warning	BOU	28 min
Aug 15, 8:26 PM MDT	Areal Flood Advisory	BOU	2 hr
Aug 16, 5:42 AM MDT	Flash Flood Watch	BOU	15 hr
Aug 16, 12:08 PM MDT	Mesoscale Discussion	SPC	3 hr
Aug 16, 2:53 PM MDT	Mesoscale Discussion	SPC	2 hr
Aug 17, 1:59 PM MDT	Mesoscale Discussion	SPC	2 hr
Aug 17, 2:32 PM MDT	Tornado Watch	SPC	7 hr
Aug 17, 3:47 PM MDT	Severe Thunderstorm Warning	BOU	43 min
Aug 17, 4:21 PM MDT	Severe Thunderstorm Warning	BOU	24 min
Aug 17, 4:28 PM MDT	Severe Thunderstorm Warning	BOU	47 min
Aug 17, 4:41 PM MDT	Mesoscale Discussion	SPC	94 min
Aug 17, 5:07 PM MDT	Severe Thunderstorm Warning	BOU	38 min
Aug 27, 6:14 PM MDT	Special Weather Statement	BOU	46 min
Aug 31, 6:46 PM MDT	Special Weather Statement	BOU	44 min
Sep 7, 4:46 PM MDT	Mesoscale Discussion	SPC	119 min
Sep 14, 3:47 PM MDT	Red Flag Warning	BOU	28 hr
Oct 6, 6:45 AM MDT	Dense Fog Advisory	BOU	3 hr
Oct 11, 3:11 AM MDT	Red Flag Warning	BOU	15 hr
Oct 14, 12:25 PM MDT	Freeze Watch	BOU	16 hr
Oct 15, 4:25 AM MDT	Frost Advisory	BOU	29 hr
Oct 23, 3:54 AM MDT	Frost Advisory	BOU	28 hr
Oct 27, 3:13 AM MDT	Frost Advisory	BOU	29 hr
Oct 28, 3:04 PM MDT	Freeze Warning	BOU	18 hr
Nov 9, 3:05 PM MST	Blizzard Watch	BOU	14 hr
Nov 10, 5:05 AM MST	Blizzard Warning	BOU	30 hr
Nov 11, 1:27 AM MST	Mesoscale Discussion	SPC	6 hr
Nov 15, 3:36 PM MST	Blizzard Watch	BOU	14 hr
Nov 16, 5:57 AM MST	Blizzard Warning	BOU	32 hr
Nov 17, 4:32 AM MST	Mesoscale Discussion	SPC	4 hr
Nov 17, 9:27 AM MST	Mesoscale Discussion	SPC	4 hr
Nov 25, 10:25 AM MST	Winter Weather Advisory	BOU	42 hr
Dec 14, 3:45 AM MST	Winter Storm Watch	BOU	11 hr
Dec 14, 3:12 PM MST	Winter Storm Warning	BOU	26 hr
Dec 23, 3:14 AM MST	Dense Fog Advisory	BOU	7 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	25
Tornado Warning	11
Severe Thunderstorm Watch	8
Tornado Watch	7
Mesoscale Discussion	43
Special Weather Statement	15
Flooding
Areal Flood Warning	5
Flash Flood Warning	1
River Flood Warning	6
Flash Flood Watch	7
River Flood Watch	1
Areal Flood Advisory	14
River Flood Advisory	1
Winter
Blizzard Warning	2
Winter Storm Warning	4
Blizzard Watch	2
Winter Storm Watch	3
Winter Weather Advisory	3
Cold
Freeze Warning	1
Freeze Watch	1
Frost Advisory	4
Wind Chill Advisory	1
Fire
Red Flag Warning	7
Fire Weather Watch	2
Fog and smoke
Dense Fog Advisory	3

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2014 2016

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.