Alert archive / Missouri / Saint Charles County

Weather alerts in Saint Charles County, Missouri, 2011

252 weather alerts in 2011, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Saint Charles County and its neighbors

Each county as a circle sized by its count in 2011. Tap one for its archive.

Alerts
252
Warnings
118
Watches
39
Advisories
33
Busiest month
June72 alerts
Busiest day
April 19, 201122 alerts

Over time

By month

Warning verification

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

6 of 11 tornado warnings covering Saint Charles County in 2011 had a tornado report inside them; 2 of 2 tornado reports fell inside a warning, on average 39 minutes after it went out.

Saint Charles County, 2011

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings11645%2100%39 min
Severe thunderstorm warnings704437%6467%21 min
Flash flood warnings3233%4100%139 min

Each office's whole area, 2011

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS St. Louis, MO: tornado warnings1352184%5680%23 min
NWS St. Louis, MO: severe thunderstorm warnings51123754%1,03166%23 min
NWS St. Louis, MO: flash flood warnings803457%8483%150 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.

IssuedProductOfficeLasted
Jan 10, 3:27 AM CSTWinter Weather AdvisoryLSX39 hr
Jan 18, 3:33 PM CSTWinter Weather AdvisoryLSX48 hr
Jan 19, 12:50 PM CSTWinter Storm WarningLSX26 hr
Jan 19, 7:25 PM CSTMesoscale DiscussionSPC4 hr
Jan 22, 4:11 AM CSTWinter Weather AdvisoryLSX34 hr
Jan 23, 10:21 PM CSTWinter Weather AdvisoryLSX11 hr
Jan 29, 8:30 PM CSTWinter Storm WatchLSX19 hr
Jan 30, 3:56 PM CSTWinter Storm WarningLSX60 hr
Jan 31, 11:52 AM CSTMesoscale DiscussionSPC4 hr
Jan 31, 2:08 PM CSTBlizzard WarningLSX46 hr
Feb 1, 6:54 AM CSTMesoscale DiscussionSPC5 hr
Feb 1, 10:36 AM CSTMesoscale DiscussionSPC6 hr
Feb 1, 11:42 AM CSTMesoscale DiscussionSPC5 hr
Feb 1, 3:36 PM CSTMesoscale DiscussionSPC6 hr
Feb 2, 3:55 AM CSTWind Chill AdvisoryLSX30 hr
Feb 4, 3:55 PM CSTWinter Weather AdvisoryLSX19 hr
Feb 21, 12:33 PM CSTRiver Flood WarningLSX5 days
Feb 27, 8:25 PM CSTMesoscale DiscussionSPC65 min
Feb 27, 9:40 PM CSTTornado WatchSPC6 hr
Feb 27, 10:41 PM CSTMesoscale DiscussionSPC94 min
Feb 27, 10:47 PM CSTTornado WarningLSX43 min
Feb 27, 11:18 PM CSTTornado WarningLSX42 min
Feb 28, 2:19 AM CSTRiver Flood WarningLSX4 days
Mar 1, 11:10 AM CSTRiver Flood WarningLSX48 hr
Mar 3, 3:42 PM CSTFlash Flood WatchLSX36 hr
Mar 4, 1:33 PM CSTSevere Thunderstorm WatchSPC5 hr
Mar 4, 3:22 PM CSTMesoscale DiscussionSPC83 min
Mar 4, 4:39 PM CSTSevere Thunderstorm WarningLSX51 min
Mar 4, 4:54 PM CSTTornado WatchSPC118 min
Mar 4, 5:23 PM CSTSevere Thunderstorm WarningLSX29 min
Mar 4, 6:20 PM CSTFlash Flood WarningLSX5 hr
Mar 4, 9:57 PM CSTRiver Flood WarningLSX21 hr
Mar 5, 9:52 PM CSTRiver Flood WarningLSX18 hr
Mar 14, 12:00 AM CDTWinter Weather AdvisoryLSX16 hr
Mar 23, 12:45 PM CDTRiver Flood WarningLSX114 days
Mar 25, 3:26 PM CDTWinter Weather AdvisoryLSX31 hr
Mar 26, 4:05 PM CDTFreeze WarningLSX17 hr
Mar 27, 4:27 AM CDTFreeze WarningLSX24 hr
Apr 2, 4:05 AM CDTWind AdvisoryLSX40 hr
Apr 4, 1:29 AM CDTMesoscale DiscussionSPC91 min
Apr 4, 3:55 AM CDTSevere Thunderstorm WarningLSX35 min
Apr 6, 5:34 AM CDTRed Flag WarningLSX13 hr
Apr 9, 4:12 AM CDTMesoscale DiscussionSPC93 min
Apr 9, 5:08 AM CDTSevere Thunderstorm WarningLSX22 min
Apr 9, 5:44 AM CDTAreal Flood AdvisoryLSX3 hr
Apr 10, 6:05 PM CDTTornado WatchSPC7 hr
Apr 10, 10:57 PM CDTSevere Thunderstorm WarningLSX48 min
Apr 15, 12:29 PM CDTMesoscale DiscussionSPC61 min
Apr 15, 12:47 PM CDTTornado WatchSPC9 hr
Apr 15, 2:20 PM CDTSevere Thunderstorm WarningLSX40 min
Apr 15, 2:54 PM CDTSevere Thunderstorm WarningLSX51 min
Apr 15, 3:32 PM CDTMesoscale DiscussionSPC58 min
Apr 15, 4:03 PM CDTSevere Thunderstorm WarningLSX42 min
Apr 15, 4:43 PM CDTSevere Thunderstorm WarningLSX47 min
Apr 17, 11:15 AM CDTRiver Flood WarningLSX30 days
Apr 18, 11:41 PM CDTMesoscale DiscussionSPC94 min
Apr 19, 2:53 AM CDTMesoscale DiscussionSPC67 min
Apr 19, 3:11 AM CDTSevere Thunderstorm WatchSPC7 hr
Apr 19, 5:23 AM CDTSevere Thunderstorm WarningLSX37 min
Apr 19, 5:43 AM CDTSevere Thunderstorm WarningLSX47 min
Apr 19, 5:52 AM CDTMesoscale DiscussionSPC83 min
Apr 19, 6:21 AM CDTAreal Flood AdvisoryLSX3 hr
Apr 19, 6:26 AM CDTSevere Thunderstorm WarningLSX49 min
Apr 19, 7:08 AM CDTSevere Thunderstorm WarningLSX37 min
Apr 19, 8:05 AM CDTRiver Flood WarningLSX30 hr
Apr 19, 12:40 PM CDTMesoscale DiscussionSPC95 min
Apr 19, 1:00 PM CDTTornado WatchSPC10 hr
Apr 19, 4:41 PM CDTSevere Thunderstorm WarningLSX49 min
Apr 19, 5:01 PM CDTSevere Thunderstorm WarningLSX44 min
Apr 19, 5:13 PM CDTSevere Thunderstorm WarningLSX47 min
Apr 19, 5:28 PM CDTSevere Thunderstorm WarningLSX47 min
Apr 19, 5:47 PM CDTMesoscale DiscussionSPC88 min
Apr 19, 5:56 PM CDTSevere Thunderstorm WarningLSX34 min
Apr 19, 6:12 PM CDTSevere Thunderstorm WarningLSX48 min
Apr 19, 6:30 PM CDTFlash Flood WarningLSX3 hr
Apr 19, 6:45 PM CDTSevere Thunderstorm WarningLSX30 min
Apr 19, 6:56 PM CDTSevere Thunderstorm WarningLSX64 min
Apr 19, 9:37 PM CDTSevere Thunderstorm WarningLSX21 min
Apr 21, 3:45 PM CDTFlash Flood WatchLSX6 days
Apr 22, 10:09 AM CDTMesoscale DiscussionSPC66 min
Apr 22, 10:17 AM CDTSevere Thunderstorm WarningLSX43 min
Apr 22, 11:00 AM CDTSevere Thunderstorm WarningLSX45 min
Apr 22, 12:34 PM CDTRiver Flood WarningLSX26 hr
Apr 22, 1:04 PM CDTMesoscale DiscussionSPC116 min
Apr 22, 3:34 PM CDTTornado WatchSPC6 hr
Apr 22, 5:21 PM CDTMesoscale DiscussionSPC114 min
Apr 22, 6:55 PM CDTTornado WarningLSX50 min
Apr 22, 6:58 PM CDTSevere Thunderstorm WarningLSX47 min
Apr 22, 7:11 PM CDTSevere Thunderstorm WarningLSX49 min
Apr 22, 7:20 PM CDTTornado WarningLSX40 min
Apr 22, 7:36 PM CDTTornado WarningLSX39 min
Apr 22, 9:20 PM CDTMesoscale DiscussionSPC55 min
Apr 24, 9:39 AM CDTRiver Flood WarningLSX7 days
Apr 24, 10:57 AM CDTRiver Flood WarningLSX45 hr
Apr 28, 12:38 PM CDTMesoscale DiscussionSPC97 min
May 3, 3:36 AM CDTFrost AdvisoryLSX28 hr
May 10, 12:25 PM CDTSevere Thunderstorm WarningLSX35 min
May 11, 2:07 PM CDTSevere Thunderstorm WarningLSX38 min
May 11, 2:18 PM CDTMesoscale DiscussionSPC57 min
May 11, 2:24 PM CDTSevere Thunderstorm WarningLSX29 min
May 13, 4:40 PM CDTMesoscale DiscussionSPC95 min
May 21, 9:26 PM CDTRiver Flood WarningLSX55 days
May 21, 10:55 PM CDTRiver Flood WarningLSX3 days
May 22, 12:51 PM CDTTornado WatchSPC10 hr
May 22, 4:32 PM CDTSevere Thunderstorm WarningLSX58 min
May 22, 5:37 PM CDTTornado WarningLSX38 min
May 22, 7:45 PM CDTSevere Thunderstorm WarningLSX45 min
May 22, 7:52 PM CDTMesoscale DiscussionSPC53 min
May 22, 8:01 PM CDTSevere Thunderstorm WarningLSX29 min
May 22, 8:15 PM CDTSevere Thunderstorm WarningLSX45 min
May 22, 8:26 PM CDTTornado WatchSPC8 hr
May 23, 12:34 AM CDTRiver Flood WarningLSX66 hr
May 23, 10:55 AM CDTSevere Thunderstorm WatchSPC7 hr
May 23, 11:41 AM CDTSevere Thunderstorm WarningLSX49 min
May 23, 12:04 PM CDTSevere Thunderstorm WarningLSX41 min
May 23, 12:34 PM CDTAreal Flood AdvisoryLSX3 hr
May 24, 1:38 PM CDTSevere Thunderstorm WatchSPC5 hr
May 24, 3:44 PM CDTFlash Flood WatchLSX32 hr
May 24, 4:55 PM CDTMesoscale DiscussionSPC65 min
May 25, 12:48 AM CDTMesoscale DiscussionSPC57 min
May 25, 1:22 AM CDTTornado WatchSPC7 hr
May 25, 4:15 AM CDTSevere Thunderstorm WarningLSX35 min
May 25, 4:58 AM CDTMesoscale DiscussionSPC92 min
May 25, 11:03 AM CDTRiver Flood WarningLSX20 days
May 25, 11:09 AM CDTTornado Watch PDSSPC10 hr
May 25, 2:32 PM CDTMesoscale DiscussionSPC58 min
May 25, 3:09 PM CDTSevere Thunderstorm WarningLSX36 min
May 25, 3:16 PM CDTTornado WarningLSX44 min
May 25, 3:41 PM CDTSevere Thunderstorm WarningLSX38 min
May 25, 4:00 PM CDTSevere Thunderstorm WarningLSX45 min
May 25, 4:05 PM CDTSevere Thunderstorm WarningLSX40 min
May 25, 4:11 PM CDTTornado WarningLSX49 min
May 25, 4:40 PM CDTTornado WarningLSX21 min
May 25, 5:00 PM CDTSevere Thunderstorm WarningLSX25 min
May 25, 7:46 PM CDTRiver Flood WarningLSX16 hr
May 28, 5:39 PM CDTMesoscale DiscussionSPC66 min
Jun 2, 2:57 PM CDTMesoscale DiscussionSPC2 hr
Jun 2, 3:46 PM CDTTornado WatchSPC4 hr
Jun 2, 6:20 PM CDTMesoscale DiscussionSPC55 min
Jun 4, 3:45 AM CDTHeat AdvisoryLSX5 days
Jun 5, 2:52 AM CDTMesoscale DiscussionSPC2 hr
Jun 5, 5:00 AM CDTSevere Thunderstorm WatchSPC7 hr
Jun 10, 4:18 PM CDTMesoscale DiscussionSPC87 min
Jun 10, 4:57 PM CDTSevere Thunderstorm WatchSPC7 hr
Jun 10, 7:47 PM CDTMesoscale DiscussionSPC58 min
Jun 10, 9:33 PM CDTSevere Thunderstorm WarningLSX42 min
Jun 10, 9:51 PM CDTSevere Thunderstorm WarningLSX39 min
Jun 10, 9:58 PM CDTSevere Thunderstorm WarningLSX35 min
Jun 10, 10:07 PM CDTSevere Thunderstorm WarningLSX39 min
Jun 10, 10:30 PM CDTSevere Thunderstorm WarningLSX23 min
Jun 10, 10:56 PM CDTMesoscale DiscussionSPC94 min
Jun 13, 5:16 AM CDTSevere Thunderstorm WatchSPC8 hr
Jun 13, 6:52 AM CDTMesoscale DiscussionSPC83 min
Jun 13, 8:33 AM CDTSevere Thunderstorm WarningLSX42 min
Jun 13, 10:04 AM CDTMesoscale DiscussionSPC86 min
Jun 13, 4:02 PM CDTFlash Flood WatchLSX39 hr
Jun 13, 11:57 PM CDTMesoscale DiscussionSPC93 min
Jun 14, 1:50 AM CDTSevere Thunderstorm WarningLSX16 min
Jun 14, 2:56 PM CDTMesoscale DiscussionSPC94 min
Jun 15, 3:23 AM CDTSevere Thunderstorm WarningLSX41 min
Jun 15, 3:29 AM CDTSevere Thunderstorm WarningLSX46 min
Jun 15, 3:45 AM CDTAreal Flood AdvisoryLSX3 hr
Jun 15, 4:24 AM CDTMesoscale DiscussionSPC96 min
Jun 17, 11:51 AM CDTAreal Flood AdvisoryLSX3 hr
Jun 17, 4:44 PM CDTRiver Flood WarningLSX3 hr
Jun 18, 2:44 AM CDTSevere Thunderstorm WatchSPC5 hr
Jun 18, 4:30 AM CDTSevere Thunderstorm WarningLSX60 min
Jun 18, 4:56 AM CDTTornado WarningLSX49 min
Jun 18, 5:18 AM CDTSevere Thunderstorm WarningLSX57 min
Jun 18, 5:30 AM CDTTornado WarningLSX19 min
Jun 18, 5:39 AM CDTMesoscale DiscussionSPC66 min
Jun 18, 5:50 AM CDTAreal Flood AdvisoryLSX3 hr
Jun 18, 6:09 AM CDTSevere Thunderstorm WarningLSX51 min
Jun 18, 3:57 PM CDTFlash Flood WatchLSX15 hr
Jun 18, 8:26 PM CDTSevere Thunderstorm WatchSPC8 hr
Jun 19, 12:52 AM CDTSevere Thunderstorm WarningLSX53 min
Jun 19, 10:10 AM CDTRiver Flood WarningLSX11 hr
Jun 21, 12:56 PM CDTMesoscale DiscussionSPC64 min
Jun 21, 1:22 PM CDTTornado WatchSPC9 hr
Jun 21, 3:31 PM CDTMesoscale DiscussionSPC89 min
Jun 25, 3:51 AM CDTMesoscale DiscussionSPC84 min
Jun 25, 11:17 AM CDTMesoscale DiscussionSPC118 min
Jun 25, 1:06 PM CDTSevere Thunderstorm WatchSPC3 hr
Jun 25, 7:07 PM CDTMesoscale DiscussionSPC113 min
Jun 25, 7:36 PM CDTSevere Thunderstorm WarningLSX39 min
Jun 25, 7:36 PM CDTSevere Thunderstorm WatchSPC6 hr
Jun 25, 8:09 PM CDTSevere Thunderstorm WarningLSX51 min
Jun 25, 8:13 PM CDTSevere Thunderstorm WarningLSX47 min
Jun 25, 11:11 PM CDTSevere Thunderstorm WarningLSX49 min
Jun 25, 11:42 PM CDTAreal Flood AdvisoryLSX6 hr
Jun 26, 12:21 AM CDTFlash Flood WarningLSX6 hr
Jun 26, 12:43 AM CDTSevere Thunderstorm WarningLSX47 min
Jun 26, 1:43 AM CDTRiver Flood WarningLSX13 hr
Jun 26, 1:58 AM CDTSevere Thunderstorm WatchSPC4 hr
Jun 26, 6:29 AM CDTAreal Flood WarningLSX12 hr
Jun 26, 2:43 PM CDTFlash Flood WatchLSX31 hr
Jun 26, 6:22 PM CDTMesoscale DiscussionSPC83 min
Jun 26, 6:55 PM CDTTornado WatchSPC7 hr
Jun 26, 10:06 PM CDTMesoscale DiscussionSPC84 min
Jun 27, 12:58 AM CDTMesoscale DiscussionSPC92 min
Jun 27, 1:27 AM CDTSevere Thunderstorm WarningLSX63 min
Jun 27, 1:32 AM CDTSevere Thunderstorm WatchSPC7 hr
Jun 27, 2:04 AM CDTSevere Thunderstorm WarningLSX41 min
Jun 27, 2:17 AM CDTSevere Thunderstorm WarningLSX43 min
Jun 27, 2:42 AM CDTSevere Thunderstorm WarningLSX48 min
Jun 27, 5:38 AM CDTMesoscale DiscussionSPC97 min
Jun 27, 3:11 PM CDTRiver Flood WarningLSX44 days
Jun 29, 4:09 PM CDTHeat AdvisoryLSX4 days
Jul 2, 6:17 PM CDTMesoscale DiscussionSPC58 min
Jul 3, 12:26 PM CDTMesoscale DiscussionSPC64 min
Jul 3, 1:15 PM CDTSevere Thunderstorm WatchSPC6 hr
Jul 3, 1:29 PM CDTSevere Thunderstorm WarningLSX46 min
Jul 3, 2:12 PM CDTSevere Thunderstorm WarningLSX48 min
Jul 3, 2:50 PM CDTSevere Thunderstorm WarningLSX40 min
Jul 3, 3:26 PM CDTSevere Thunderstorm WarningLSX64 min
Jul 3, 3:35 PM CDTMesoscale DiscussionSPC55 min
Jul 3, 3:56 PM CDTSevere Thunderstorm WarningLSX49 min
Jul 3, 4:34 PM CDTAreal Flood AdvisoryLSX5 hr
Jul 3, 5:19 PM CDTMesoscale DiscussionSPC26 min
Jul 7, 5:03 PM CDTSevere Thunderstorm WatchSPC7 hr
Jul 7, 5:46 PM CDTAreal Flood AdvisoryLSX3 hr
Jul 8, 3:17 PM CDTHeat AdvisoryLSX4 days
Jul 10, 11:54 AM CDTExcessive Heat WarningLSX55 hr
Jul 12, 1:00 PM CDTMesoscale DiscussionSPC2 hr
Jul 12, 1:45 PM CDTSevere Thunderstorm WatchSPC7 hr
Jul 12, 3:48 PM CDTMesoscale DiscussionSPC87 min
Jul 12, 5:03 PM CDTSevere Thunderstorm WarningLSX57 min
Jul 12, 6:43 PM CDTMesoscale DiscussionSPC62 min
Jul 14, 3:29 PM CDTExcessive Heat WatchLSX23 hr
Jul 15, 2:23 PM CDTExcessive Heat WarningLSX19 days
Aug 5, 4:10 AM CDTHeat AdvisoryLSX63 hr
Aug 7, 5:20 PM CDTMesoscale DiscussionSPC115 min
Aug 7, 5:41 PM CDTSevere Thunderstorm WatchSPC6 hr
Aug 12, 1:44 PM CDTMesoscale DiscussionSPC91 min
Aug 20, 8:55 PM CDTRiver Flood WarningLSX7 days
Aug 23, 3:35 AM CDTHeat AdvisoryLSX39 hr
Aug 24, 6:08 PM CDTSevere Thunderstorm WatchSPC6 hr
Aug 30, 4:15 PM CDTHeat AdvisoryLSX4 days
Sep 3, 5:57 PM CDTSevere Thunderstorm WarningLSX19 min
Sep 19, 11:52 PM CDTDense Fog AdvisoryLSX9 hr
Sep 22, 11:52 PM CDTDense Fog AdvisoryLSX10 hr
Oct 1, 2:25 PM CDTFrost AdvisoryLSX18 hr
Oct 12, 4:58 AM CDTAreal Flood AdvisoryLSX4 hr
Oct 20, 3:48 AM CDTFrost AdvisoryLSX29 hr
Oct 27, 3:55 AM CDTFrost AdvisoryLSX28 hr
Nov 5, 6:12 AM CDTDense Fog AdvisoryLSX5 hr
Nov 8, 1:17 AM CSTMesoscale DiscussionSPC118 min
Nov 9, 3:03 PM CSTFreeze WarningLSX15 hr
Nov 10, 3:09 PM CSTFreeze WarningLSX17 hr
Nov 18, 4:29 AM CSTRed Flag WarningLSX13 hr
Dec 19, 9:24 PM CSTRiver Flood WarningLSX9 hr
Dec 20, 10:59 PM CSTDense Fog AdvisoryLSX7 hr

By product

Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20102012

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.