Alert archive / Iowa / Polk County

Weather alerts in Polk County, Iowa, 2015

151 weather alerts in 2015, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Polk County and its neighbors

Each county as a circle sized by its count in 2015. Tap one for its archive.

Alerts
151
Warnings
48
Watches
25
Advisories
30
Busiest month
June33 alerts
Busiest day
June 25, 20159 alerts

Over time

By month

Warning verification

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

0 of 3 tornado reports fell inside a warning.

Polk County, 2015

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings030%
Severe thunderstorm warnings9544%1283%16 min
Flash flood warnings220%743%125 min

Each office's whole area, 2015

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Des Moines, IA: tornado warnings381463%3762%13 min
NWS Des Moines, IA: severe thunderstorm warnings20110150%30178%19 min
NWS Des Moines, IA: flash flood warnings392244%8686%121 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 3, 3:51 AM CSTWinter Weather AdvisoryDMX26 hr
Jan 4, 4:00 AM CSTWinter Storm WatchDMX24 hr
Jan 4, 6:07 AM CSTWind Chill AdvisoryDMX27 hr
Jan 4, 3:42 PM CSTWinter Storm WarningDMX31 hr
Jan 5, 12:25 PM CSTMesoscale DiscussionSPC6 hr
Jan 6, 4:15 AM CSTWind Chill WarningDMX32 hr
Jan 6, 4:15 AM CSTWind Chill AdvisoryDMX53 hr
Jan 7, 3:44 PM CSTWinter Weather AdvisoryDMX38 hr
Jan 8, 4:57 PM CSTSpecial Weather StatementDMX48 min
Jan 9, 5:38 AM CSTWind Chill AdvisoryDMX6 hr
Jan 28, 3:36 PM CSTWind AdvisoryDMX17 hr
Jan 30, 10:48 AM CSTWinter Storm WatchDMX17 hr
Jan 31, 3:31 AM CSTWinter Storm WarningDMX41 hr
Jan 31, 10:13 PM CSTMesoscale DiscussionSPC6 hr
Feb 17, 3:51 AM CSTWind Chill AdvisoryDMX32 hr
Feb 20, 3:08 PM CSTWind Chill AdvisoryDMX67 hr
Feb 24, 11:34 AM CSTWinter Storm WatchDMX4 hr
Feb 24, 3:19 PM CSTWinter Storm WarningDMX30 hr
Feb 24, 3:19 PM CSTWinter Weather AdvisoryDMX30 hr
Feb 26, 9:48 PM CSTWind Chill AdvisoryDMX11 hr
Mar 2, 4:11 PM CSTWinter Weather AdvisoryDMX19 hr
Mar 14, 11:06 AM CDTFire Weather WatchDMX17 hr
Mar 15, 3:41 AM CDTRed Flag WarningDMX15 hr
Mar 16, 3:43 AM CDTRed Flag WarningDMX15 hr
Mar 28, 3:44 PM CDTWind AdvisoryDMX26 hr
Mar 30, 4:14 AM CDTRed Flag WarningDMX15 hr
Mar 31, 3:38 PM CDTFire Weather WatchDMX12 hr
Apr 1, 3:46 AM CDTRed Flag WarningDMX15 hr
Apr 8, 12:09 PM CDTSpecial Weather StatementDMX36 min
Apr 8, 12:23 PM CDTSevere Thunderstorm WarningDMX37 min
Apr 12, 10:48 PM CDTSpecial Weather StatementDMX42 min
Apr 18, 6:49 PM CDTSpecial Weather StatementDMX41 min
Apr 20, 3:45 AM CDTWind AdvisoryDMX15 hr
Apr 22, 3:23 PM CDTFreeze WarningDMX17 hr
May 10, 9:19 PM CDTMesoscale DiscussionSPC56 min
May 15, 12:05 AM CDTDense Fog AdvisoryDMX9 hr
May 25, 5:33 PM CDTSevere Thunderstorm WatchSPC6 hr
May 25, 8:18 PM CDTMesoscale DiscussionSPC87 min
Jun 6, 3:37 PM CDTFlash Flood WatchDMX12 hr
Jun 6, 11:23 PM CDTSevere Thunderstorm WatchSPC6 hr
Jun 7, 1:43 AM CDTSpecial Weather StatementDMX47 min
Jun 7, 1:56 AM CDTMesoscale DiscussionSPC2 hr
Jun 7, 2:32 AM CDTSpecial Weather StatementDMX43 min
Jun 10, 2:12 PM CDTFlash Flood WatchDMX38 hr
Jun 10, 8:38 PM CDTSpecial Weather StatementDMX52 min
Jun 11, 12:52 PM CDTRiver Flood WarningDMX8 days
Jun 11, 12:53 PM CDTRiver Flood WarningDMX7 days
Jun 11, 1:27 PM CDTRiver Flood WarningDMX42 hr
Jun 15, 3:18 AM CDTFlash Flood WarningDMX6 hr
Jun 15, 4:17 AM CDTRiver Flood WarningDMX55 hr
Jun 15, 5:25 PM CDTRiver Flood WarningDMX40 hr
Jun 20, 12:48 PM CDTMesoscale DiscussionSPC117 min
Jun 20, 3:10 PM CDTMesoscale DiscussionSPC2 hr
Jun 20, 3:49 PM CDTTornado WatchSPC7 hr
Jun 20, 6:33 PM CDTMesoscale DiscussionSPC57 min
Jun 20, 10:12 PM CDTMesoscale DiscussionSPC63 min
Jun 22, 1:22 PM CDTMesoscale DiscussionSPC113 min
Jun 23, 3:59 PM CDTFlash Flood WatchDMX38 hr
Jun 24, 12:39 AM CDTMesoscale DiscussionSPC66 min
Jun 24, 5:58 PM CDTMesoscale DiscussionSPC2 hr
Jun 24, 6:21 PM CDTTornado WatchSPC5 hr
Jun 24, 11:26 PM CDTSevere Thunderstorm WatchSPC3 hr
Jun 25, 12:59 AM CDTFlash Flood WarningDMX6 hr
Jun 25, 1:25 AM CDTSevere Thunderstorm WarningDMX35 min
Jun 25, 1:54 AM CDTRiver Flood WarningDMX6 days
Jun 25, 1:54 AM CDTRiver Flood WarningDMX5 days
Jun 25, 1:54 AM CDTRiver Flood WarningDMX5 days
Jun 25, 2:27 AM CDTRiver Flood WarningDMX6 days
Jun 25, 5:07 AM CDTRiver Flood WarningDMX4 days
Jun 25, 6:57 AM CDTAreal Flood WarningDMX9 hr
Jun 28, 4:38 AM CDTSpecial Weather StatementDMX52 min
Jul 11, 3:19 PM CDTHeat AdvisoryDMX28 hr
Jul 11, 3:19 PM CDTHeat AdvisoryDMX52 hr
Jul 15, 11:52 PM CDTFlash Flood WatchDMX10 hr
Jul 18, 4:12 AM CDTHeat AdvisoryDMX12 hr
Jul 24, 11:16 AM CDTSpecial Weather StatementDMX59 min
Jul 26, 1:13 AM CDTMesoscale DiscussionSPC3 hr
Jul 26, 4:49 AM CDTSevere Thunderstorm WarningDMX26 min
Jul 27, 11:41 AM CDTSpecial Weather StatementDMX64 min
Jul 27, 12:13 PM CDTSevere Thunderstorm WarningDMX32 min
Jul 27, 12:40 PM CDTMesoscale DiscussionSPC3 hr
Jul 27, 12:45 PM CDTSpecial Weather StatementDMX45 min
Jul 28, 3:40 PM CDTMesoscale DiscussionSPC2 hr
Jul 28, 3:59 PM CDTFlash Flood WatchDMX11 hr
Jul 28, 7:56 PM CDTSpecial Weather StatementDMX34 min
Jul 28, 8:04 PM CDTMesoscale DiscussionSPC116 min
Jul 28, 9:39 PM CDTRiver Flood WarningDMX34 hr
Jul 28, 11:58 PM CDTRiver Flood WarningDMX57 hr
Aug 2, 4:48 AM CDTMesoscale DiscussionSPC2 hr
Aug 2, 5:22 PM CDTSevere Thunderstorm WarningDMX38 min
Aug 2, 6:22 PM CDTMesoscale DiscussionSPC53 min
Aug 8, 3:42 PM CDTFlash Flood WatchDMX15 hr
Aug 8, 11:33 PM CDTSevere Thunderstorm WarningDMX42 min
Aug 9, 12:18 AM CDTSpecial Weather StatementDMX57 min
Aug 22, 2:13 PM CDTMesoscale DiscussionSPC62 min
Aug 22, 2:55 PM CDTMesoscale DiscussionSPC65 min
Aug 22, 3:48 PM CDTTornado WatchSPC8 hr
Aug 22, 6:21 PM CDTMesoscale DiscussionSPC84 min
Aug 22, 8:49 PM CDTMesoscale DiscussionSPC116 min
Aug 28, 3:01 PM CDTRiver Flood WarningDMX64 hr
Aug 29, 7:36 AM CDTRiver Flood WarningDMX4 days
Aug 30, 6:08 AM CDTDense Fog AdvisoryDMX4 hr
Sep 6, 4:06 AM CDTFlash Flood WatchDMX28 hr
Sep 6, 6:02 PM CDTSevere Thunderstorm WatchSPC7 hr
Sep 6, 8:42 PM CDTMesoscale DiscussionSPC93 min
Sep 6, 9:12 PM CDTSevere Thunderstorm WarningDMX28 min
Sep 6, 9:39 PM CDTSpecial Weather StatementDMX51 min
Sep 6, 11:41 PM CDTMesoscale DiscussionSPC64 min
Sep 7, 4:21 AM CDTFlash Flood WatchDMX30 hr
Sep 7, 10:48 PM CDTRiver Flood WarningDMX4 days
Sep 8, 1:43 PM CDTRiver Flood WarningDMX41 hr
Sep 17, 5:47 PM CDTMesoscale DiscussionSPC118 min
Oct 11, 3:59 PM CDTWind AdvisoryDMX26 hr
Oct 16, 3:54 AM CDTFrost AdvisoryDMX29 hr
Oct 18, 2:56 PM CDTRed Flag WarningDMX28 hr
Oct 21, 9:07 AM CDTSpecial Weather StatementDMX53 min
Nov 3, 8:35 AM CSTDense Fog AdvisoryDMX2 hr
Nov 5, 3:17 PM CSTMesoscale DiscussionSPC118 min
Nov 10, 3:20 AM CSTHigh Wind WatchDMX24 hr
Nov 10, 3:39 PM CSTHigh Wind WarningDMX38 hr
Nov 10, 3:39 PM CSTWind AdvisoryDMX50 hr
Nov 11, 10:17 AM CSTMesoscale DiscussionSPC118 min
Nov 11, 11:25 AM CSTTornado WatchSPC6 hr
Nov 11, 1:42 PM CSTMesoscale DiscussionSPC93 min
Nov 11, 2:13 PM CSTSpecial Weather StatementDMX92 min
Nov 11, 3:07 PM CSTSevere Thunderstorm WarningDMX53 min
Nov 11, 3:52 PM CSTSevere Thunderstorm WarningDMX53 min
Nov 18, 3:12 PM CSTWind AdvisoryDMX27 hr
Nov 18, 4:05 PM CSTWinter Storm WatchDMX36 hr
Nov 19, 3:41 PM CSTWinter Storm WarningDMX38 hr
Nov 20, 1:51 PM CSTMesoscale DiscussionSPC5 hr
Nov 20, 7:33 PM CSTMesoscale DiscussionSPC4 hr
Nov 25, 4:39 PM CSTWinter Weather AdvisoryDMX34 hr
Nov 29, 3:46 PM CSTWinter Weather AdvisoryDMX36 hr
Dec 6, 8:12 PM CSTDense Fog AdvisoryDMX15 hr
Dec 12, 4:10 PM CSTDense Fog AdvisoryDMX12 hr
Dec 13, 7:47 AM CSTFlood WatchDMX25 hr
Dec 13, 1:03 PM CSTRiver Flood WarningDMX12 days
Dec 13, 1:03 PM CSTRiver Flood WarningDMX9 days
Dec 13, 9:27 PM CSTRiver Flood WarningDMX6 days
Dec 13, 9:27 PM CSTRiver Flood WarningDMX6 days
Dec 14, 8:45 AM CSTRiver Flood WarningDMX56 hr
Dec 14, 9:59 AM CSTRiver Flood WarningDMX31 hr
Dec 14, 11:32 AM CSTRiver Flood WarningDMX4 days
Dec 24, 3:27 AM CSTWinter Weather AdvisoryDMX15 hr
Dec 25, 4:38 AM CSTDense Fog AdvisoryDMX4 hr
Dec 25, 9:10 AM CSTDense Fog AdvisoryDMX6 hr
Dec 26, 3:46 PM CSTWinter Storm WatchDMX23 hr
Dec 27, 4:46 AM CSTWinter Storm WarningDMX49 hr
Dec 28, 3:35 AM CSTMesoscale DiscussionSPC6 hr
Dec 28, 3:42 PM CSTMesoscale DiscussionSPC4 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 archive20142016

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.