Alert archive / Missouri / Jefferson County

Weather alerts in Jefferson County, Missouri, 2010

179 weather alerts in 2010, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Jefferson County and its neighbors

Each county as a circle sized by its count in 2010. Tap one for its archive.

Alerts: 179
Warnings: 60
Watches: 43
Advisories: 31
Busiest month: June31 alerts
Busiest day: May 1, 201010 alerts

Over time

By month

Warning verification

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

5 of 12 tornado warnings covering Jefferson County in 2010 had a tornado report inside them; 11 of 11 tornado reports fell inside a warning, on average 41 minutes after it went out.

Jefferson County, 2010

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	12	5	58%	11	100%	41 min
Severe thunderstorm warnings	22	15	32%	20	50%	12 min
Flash flood warnings	6	2	67%	1	100%	28 min

Each office's whole area, 2010

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS St. Louis, MO: tornado warnings	94	16	83%	43	84%	33 min
NWS St. Louis, MO: severe thunderstorm warnings	301	122	59%	404	62%	23 min
NWS St. Louis, MO: flash flood warnings	112	44	61%	122	73%	122 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, 3:50 PM CST	Winter Storm Watch	LSX	12 hr
Jan 6, 4:16 AM CST	Winter Weather Advisory	LSX	37 hr
Jan 7, 4:16 AM CST	Wind Chill Advisory	LSX	24 hr
Jan 7, 3:54 PM CST	Wind Chill Advisory	LSX	43 hr
Jan 15, 3:42 PM CST	Dense Fog Advisory	LSX	20 hr
Jan 15, 3:42 PM CST	Freezing Fog Advisory	LSX	20 hr
Jan 16, 2:33 PM CST	Dense Fog Advisory	LSX	21 hr
Jan 17, 2:12 PM CST	Dense Fog Advisory	LSX	22 hr
Jan 18, 3:00 PM CST	Dense Fog Advisory	LSX	21 hr
Jan 20, 3:55 PM CST	Dense Fog Advisory	LSX	17 hr
Jan 24, 10:48 AM CST	River Flood Warning	LSX	4 days
Feb 4, 4:08 AM CST	Winter Weather Advisory	LSX	44 hr
Feb 6, 4:18 AM CST	Winter Storm Watch	LSX	36 hr
Feb 7, 3:55 PM CST	Winter Weather Advisory	LSX	45 hr
Feb 12, 3:29 PM CST	Winter Weather Advisory	LSX	63 hr
Mar 10, 7:48 PM CST	Tornado Watch	SPC	6 hr
Mar 10, 11:08 PM CST	Mesoscale Discussion	SPC	97 min
Mar 11, 8:31 PM CST	River Flood Warning	LSX	33 days
Mar 30, 2:47 PM CDT	Fire Weather Watch	LSX	20 hr
Mar 31, 10:23 AM CDT	Red Flag Warning	LSX	8 hr
Apr 4, 8:43 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Apr 4, 11:16 PM CDT	Mesoscale Discussion	SPC	59 min
Apr 5, 1:56 AM CDT	Mesoscale Discussion	SPC	94 min
Apr 5, 12:28 PM CDT	Mesoscale Discussion	SPC	62 min
Apr 7, 1:24 PM CDT	Tornado Watch	SPC	8 hr
Apr 8, 4:16 AM CDT	Frost Advisory	LSX	29 hr
Apr 17, 3:34 PM CDT	Frost Advisory	LSX	16 hr
Apr 24, 11:08 AM CDT	Mesoscale Discussion	SPC	67 min
Apr 24, 2:52 PM CDT	Mesoscale Discussion	SPC	53 min
Apr 24, 3:20 PM CDT	Tornado Watch	SPC	7 hr
Apr 24, 3:31 PM CDT	Severe Thunderstorm Warning	LSX	44 min
Apr 24, 3:59 PM CDT	Tornado Warning	LSX	31 min
Apr 24, 4:20 PM CDT	Severe Thunderstorm Warning	LSX	25 min
Apr 24, 4:25 PM CDT	Tornado Warning	LSX	35 min
Apr 24, 5:14 PM CDT	Mesoscale Discussion	SPC	61 min
Apr 25, 9:21 PM CDT	River Flood Warning	LSX	7 days
Apr 30, 2:08 PM CDT	Mesoscale Discussion	SPC	67 min
Apr 30, 2:40 PM CDT	Tornado Watch	SPC	6 hr
Apr 30, 7:12 PM CDT	Mesoscale Discussion	SPC	63 min
Apr 30, 7:40 PM CDT	Tornado Warning	LSX	50 min
Apr 30, 7:55 PM CDT	Tornado Warning	LSX	50 min
Apr 30, 8:14 PM CDT	Flash Flood Warning	LSX	6 hr
Apr 30, 8:21 PM CDT	Tornado Warning	LSX	39 min
Apr 30, 8:36 PM CDT	Mesoscale Discussion	SPC	54 min
Apr 30, 8:54 PM CDT	Tornado Warning	LSX	51 min
Apr 30, 9:02 PM CDT	Tornado Warning	LSX	29 min
Apr 30, 9:03 PM CDT	Tornado Watch	SPC	6 hr
May 1, 3:54 AM CDT	Flash Flood Watch	LSX	23 hr
May 1, 10:14 PM CDT	Tornado Watch	SPC	7 hr
May 3, 12:54 PM CDT	Mesoscale Discussion	SPC	96 min
May 3, 1:45 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
May 3, 2:12 PM CDT	Severe Thunderstorm Warning	LSX	48 min
May 3, 5:12 PM CDT	Mesoscale Discussion	SPC	93 min
May 8, 4:02 AM CDT	Frost Advisory	LSX	27 hr
May 12, 3:02 AM CDT	Severe Thunderstorm Warning	LSX	58 min
May 12, 3:27 AM CDT	Severe Thunderstorm Warning	LSX	48 min
May 12, 4:00 AM CDT	Flash Flood Warning	LSX	6 hr
May 12, 4:51 AM CDT	Mesoscale Discussion	SPC	54 min
May 13, 10:30 AM CDT	River Flood Warning	LSX	17 days
May 13, 5:41 PM CDT	Mesoscale Discussion	SPC	94 min
May 16, 10:54 AM CDT	River Flood Warning	LSX	10 hr
May 20, 9:19 AM CDT	River Flood Warning	LSX	36 hr
May 20, 9:19 AM CDT	River Flood Warning	LSX	4 days
May 26, 3:52 PM CDT	Severe Thunderstorm Warning	LSX	23 min
Jun 2, 1:31 AM CDT	Mesoscale Discussion	SPC	89 min
Jun 2, 7:58 PM CDT	Mesoscale Discussion	SPC	62 min
Jun 6, 2:58 PM CDT	Flash Flood Watch	LSX	61 hr
Jun 8, 12:37 PM CDT	Severe Thunderstorm Warning	LSX	23 min
Jun 8, 10:20 PM CDT	Severe Thunderstorm Warning	LSX	37 min
Jun 9, 10:20 AM CDT	River Flood Warning	LSX	60 days
Jun 11, 4:01 AM CDT	Flash Flood Watch	LSX	12 hr
Jun 12, 1:31 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Jun 13, 11:55 AM CDT	Mesoscale Discussion	SPC	65 min
Jun 13, 12:24 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 13, 2:14 PM CDT	Mesoscale Discussion	SPC	61 min
Jun 14, 1:45 PM CDT	Mesoscale Discussion	SPC	60 min
Jun 14, 2:17 PM CDT	Severe Thunderstorm Watch	SPC	8 hr
Jun 15, 11:55 AM CDT	Mesoscale Discussion	SPC	95 min
Jun 15, 12:29 PM CDT	Severe Thunderstorm Watch	SPC	9 hr
Jun 15, 1:25 PM CDT	Severe Thunderstorm Warning	LSX	39 min
Jun 15, 1:51 PM CDT	Flash Flood Warning	LSX	6 hr
Jun 15, 2:42 PM CDT	Mesoscale Discussion	SPC	2 hr
Jun 18, 4:14 AM CDT	Heat Advisory	LSX	6 days
Jun 18, 5:20 PM CDT	Severe Thunderstorm Warning	LSX	25 min
Jun 18, 5:46 PM CDT	Severe Thunderstorm Warning	LSX	31 min
Jun 19, 2:33 AM CDT	Mesoscale Discussion	SPC	57 min
Jun 19, 2:42 AM CDT	Excessive Heat Warning	LSX	5 days
Jun 19, 1:07 PM CDT	Mesoscale Discussion	SPC	53 min
Jun 19, 1:48 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Jun 21, 12:58 PM CDT	Severe Thunderstorm Watch	SPC	4 hr
Jun 21, 4:10 PM CDT	Mesoscale Discussion	SPC	35 min
Jun 25, 1:45 PM CDT	Heat Advisory	LSX	29 hr
Jun 27, 5:04 PM CDT	Severe Thunderstorm Watch	SPC	4 hr
Jun 27, 7:17 PM CDT	Severe Thunderstorm Warning	LSX	43 min
Jun 27, 7:26 PM CDT	Mesoscale Discussion	SPC	94 min
Jul 11, 10:07 AM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 11, 12:17 PM CDT	Tornado Watch	SPC	3 hr
Jul 11, 2:06 PM CDT	Mesoscale Discussion	SPC	54 min
Jul 11, 3:37 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 12, 3:30 PM CDT	Mesoscale Discussion	SPC	90 min
Jul 12, 3:55 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 12, 7:56 PM CDT	Mesoscale Discussion	SPC	64 min
Jul 13, 2:35 PM CDT	Heat Advisory	LSX	52 hr
Jul 16, 4:06 PM CDT	Heat Advisory	LSX	38 hr
Jul 18, 5:58 AM CDT	Mesoscale Discussion	SPC	32 min
Jul 18, 6:22 AM CDT	Severe Thunderstorm Watch	SPC	5 hr
Jul 18, 8:47 AM CDT	Severe Thunderstorm Warning	LSX	43 min
Jul 19, 10:05 AM CDT	Mesoscale Discussion	SPC	85 min
Jul 19, 10:38 AM CDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 20, 5:08 AM CDT	Flash Flood Watch	LSX	22 hr
Jul 20, 7:33 AM CDT	Mesoscale Discussion	SPC	27 min
Jul 20, 7:36 AM CDT	Severe Thunderstorm Watch	SPC	4 hr
Jul 20, 10:59 AM CDT	Mesoscale Discussion	SPC	61 min
Jul 21, 3:39 PM CDT	Heat Advisory	LSX	3 days
Jul 23, 3:57 AM CDT	Excessive Heat Warning	LSX	40 hr
Jul 27, 3:32 PM CDT	Flash Flood Warning	LSX	2 hr
Jul 27, 3:50 PM CDT	Heat Advisory	LSX	28 hr
Jul 30, 1:49 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 30, 5:01 PM CDT	Mesoscale Discussion	SPC	89 min
Jul 30, 6:28 PM CDT	Mesoscale Discussion	SPC	62 min
Aug 1, 3:13 PM CDT	Heat Advisory	LSX	3 days
Aug 3, 4:43 AM CDT	Excessive Heat Warning	LSX	39 hr
Aug 5, 5:38 AM CDT	Severe Thunderstorm Warning	LSX	67 min
Aug 6, 2:56 PM CDT	Excessive Heat Watch	LSX	49 hr
Aug 8, 3:55 AM CDT	Excessive Heat Warning	LSX	7 days
Aug 12, 4:15 PM CDT	Severe Thunderstorm Warning	LSX	45 min
Aug 12, 5:28 PM CDT	Flash Flood Warning	LSX	4 hr
Aug 13, 9:34 PM CDT	Mesoscale Discussion	SPC	56 min
Aug 16, 9:22 AM CDT	River Flood Warning	LSX	34 hr
Aug 20, 11:32 AM CDT	Severe Thunderstorm Warning	LSX	28 min
Aug 21, 11:36 AM CDT	River Flood Warning	LSX	70 hr
Sep 2, 4:25 PM CDT	Mesoscale Discussion	SPC	65 min
Sep 2, 4:43 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Sep 2, 7:12 PM CDT	Mesoscale Discussion	SPC	2 hr
Sep 2, 8:47 PM CDT	Mesoscale Discussion	SPC	58 min
Sep 8, 3:48 PM CDT	Flash Flood Watch	LSX	27 hr
Sep 11, 1:41 AM CDT	Areal Flood Advisory	LSX	5 hr
Sep 18, 10:00 PM CDT	Flash Flood Warning	LSX	5 hr
Sep 18, 11:14 PM CDT	Severe Thunderstorm Warning	LSX	31 min
Sep 19, 3:17 AM CDT	Areal Flood Warning	LSX	12 hr
Oct 4, 4:16 AM CDT	Frost Advisory	LSX	28 hr
Oct 24, 3:38 PM CDT	Mesoscale Discussion	SPC	2 hr
Oct 24, 10:30 PM CDT	Severe Thunderstorm Warning	LSX	19 min
Oct 25, 9:36 PM CDT	Mesoscale Discussion	SPC	24 min
Oct 25, 10:03 PM CDT	Tornado Watch	SPC	9 hr
Oct 26, 2:21 AM CDT	Mesoscale Discussion	SPC	114 min
Oct 26, 3:31 AM CDT	Severe Thunderstorm Warning	LSX	44 min
Oct 26, 3:34 AM CDT	Severe Thunderstorm Warning	LSX	41 min
Oct 26, 3:38 AM CDT	Mesoscale Discussion	SPC	2 hr
Oct 26, 4:09 AM CDT	Severe Thunderstorm Warning	LSX	66 min
Oct 26, 7:30 PM CDT	Fire Weather Watch	LSX	9 hr
Oct 27, 4:47 AM CDT	Red Flag Warning	LSX	12 hr
Oct 27, 3:53 PM CDT	Freeze Watch	LSX	12 hr
Oct 28, 3:47 AM CDT	Freeze Warning	LSX	29 hr
Oct 29, 2:43 AM CDT	Fire Weather Watch	LSX	13 hr
Oct 29, 3:58 PM CDT	Red Flag Warning	LSX	26 hr
Nov 6, 3:47 PM CDT	Fire Weather Watch	LSX	25 hr
Nov 7, 3:57 PM CST	Red Flag Warning	LSX	26 hr
Nov 22, 4:50 PM CST	Tornado Watch	SPC	7 hr
Nov 22, 6:43 PM CST	Severe Thunderstorm Warning	LSX	36 min
Nov 22, 7:31 PM CST	Mesoscale Discussion	SPC	89 min
Nov 24, 3:48 PM CST	Flash Flood Watch	LSX	12 hr
Nov 24, 8:23 PM CST	Tornado Watch	SPC	8 hr
Nov 24, 9:26 PM CST	Areal Flood Advisory	LSX	6 hr
Nov 24, 10:31 PM CST	Tornado Warning	LSX	44 min
Nov 24, 11:03 PM CST	Tornado Warning	LSX	42 min
Nov 25, 3:31 AM CST	Areal Flood Advisory	LSX	6 hr
Dec 11, 4:15 AM CST	Winter Weather Advisory	LSX	32 hr
Dec 11, 4:09 PM CST	Wind Advisory	LSX	29 hr
Dec 12, 4:19 AM CST	Wind Chill Advisory	LSX	30 hr
Dec 15, 4:00 AM CST	Winter Weather Advisory	LSX	32 hr
Dec 23, 12:07 PM CST	Winter Weather Advisory	LSX	40 hr
Dec 31, 2:25 AM CST	Severe Thunderstorm Watch	SPC	2 hr
Dec 31, 4:05 AM CST	Mesoscale Discussion	SPC	115 min
Dec 31, 5:45 AM CST	Mesoscale Discussion	SPC	2 hr
Dec 31, 7:29 AM CST	Tornado Watch	SPC	8 hr
Dec 31, 10:56 AM CST	Tornado Warning	LSX	64 min
Dec 31, 11:22 AM CST	Tornado Warning	LSX	53 min
Dec 31, 12:29 PM CST	Tornado Warning	LSX	31 min

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	22
Tornado Warning	12
Severe Thunderstorm Watch	18
Tornado Watch	11
Mesoscale Discussion	45
Flooding
Areal Flood Warning	1
Flash Flood Warning	6
River Flood Warning	10
Flash Flood Watch	6
Areal Flood Advisory	3
Winter
Winter Storm Watch	2
Winter Weather Advisory	7
Heat
Excessive Heat Warning	4
Excessive Heat Watch	1
Heat Advisory	7
Cold
Freeze Warning	1
Freeze Watch	1
Frost Advisory	4
Wind Chill Advisory	3
Wind and dust
Wind Advisory	1
Fire
Red Flag Warning	4
Fire Weather Watch	4
Fog and smoke
Dense Fog Advisory	5
Freezing Fog Advisory	1

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2009 2011

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.