Alert archive / Iowa / Poweshiek County

Weather alerts in Poweshiek County, Iowa, 2018

137 weather alerts in 2018, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Poweshiek County and its neighbors

Each county as a circle sized by its count in 2018. Tap one for its archive.

Alerts
137
Warnings
29
Watches
22
Advisories
43
Busiest month
September24 alerts
Busiest day
October 9, 20189 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 Poweshiek County in 2018 had a tornado report inside them; 0 of 2 tornado reports fell inside a warning.

Poweshiek County, 2018

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings6267%20%
Severe thunderstorm warnings9544%475%21 min
Flash flood warnings4175%367%48 min

Each office's whole area, 2018

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Des Moines, IA: tornado warnings722368%6955%15 min
NWS Des Moines, IA: severe thunderstorm warnings30814354%42774%22 min
NWS Des Moines, IA: flash flood warnings392049%7074%86 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, 3:46 AM CSTWind Chill AdvisoryDMX30 hr
Jan 5, 4:04 PM CSTWind Chill AdvisoryDMX18 hr
Jan 10, 2:08 PM CSTWinter Weather AdvisoryDMX28 hr
Jan 11, 9:36 AM CSTMesoscale DiscussionSPC4 hr
Jan 14, 3:47 AM CSTWind Chill AdvisoryDMX56 hr
Jan 21, 6:18 PM CSTDense Fog AdvisoryDMX6 hr
Jan 26, 10:53 AM CSTWind AdvisoryDMX5 hr
Feb 4, 2:32 PM CSTWinter Weather AdvisoryDMX28 hr
Feb 5, 11:36 AM CSTMesoscale DiscussionSPC6 hr
Feb 7, 2:23 PM CSTWinter Weather AdvisoryDMX40 hr
Feb 8, 11:05 AM CSTWinter Storm WarningDMX19 hr
Feb 9, 3:05 PM CSTWinter Weather AdvisoryDMX16 hr
Feb 18, 3:45 AM CSTWinter Storm WatchDMX24 hr
Feb 18, 3:45 AM CSTWinter Weather AdvisoryDMX56 hr
Feb 20, 2:43 AM CSTMesoscale DiscussionSPC3 hr
Feb 21, 3:42 PM CSTWinter Weather AdvisoryDMX35 hr
Feb 23, 3:24 PM CSTWinter Weather AdvisoryDMX30 hr
Mar 16, 4:10 AM CDTWinter Weather AdvisoryDMX30 hr
Mar 18, 2:12 AM CDTDense Fog AdvisoryDMX8 hr
Mar 23, 4:00 AM CDTWinter Storm WarningDMX39 hr
Mar 23, 4:00 AM CDTWinter Weather AdvisoryDMX39 hr
Mar 30, 3:19 PM CDTWind AdvisoryDMX25 hr
Apr 2, 2:00 PM CDTWinter Weather AdvisoryDMX35 hr
Apr 3, 4:19 AM CDTWind AdvisoryDMX21 hr
Apr 7, 3:05 PM CDTWinter Weather AdvisoryDMX40 hr
Apr 13, 3:22 PM CDTSevere Thunderstorm WatchSPC6 hr
Apr 13, 3:54 PM CDTWinter Weather AdvisoryDMX48 hr
Apr 14, 1:31 AM CDTWind AdvisoryDMX14 hr
Apr 17, 3:54 AM CDTWinter Weather AdvisoryDMX42 hr
Apr 27, 2:42 PM CDTRed Flag WarningDMX4 hr
May 1, 10:24 AM CDTMesoscale DiscussionSPC3 hr
May 1, 5:47 PM CDTSevere Thunderstorm WatchSPC6 hr
May 1, 7:55 PM CDTMesoscale DiscussionSPC95 min
May 1, 9:38 PM CDTMesoscale DiscussionSPC67 min
May 3, 2:57 PM CDTSevere Thunderstorm WatchSPC6 hr
May 3, 7:43 PM CDTMesoscale DiscussionSPC62 min
May 3, 8:48 PM CDTSevere Thunderstorm WarningDMX42 min
May 12, 1:04 AM CDTMesoscale DiscussionSPC116 min
May 22, 2:05 AM CDTDense Fog AdvisoryDMX7 hr
May 25, 8:25 PM CDTSevere Thunderstorm WarningDMX19 min
May 26, 4:29 PM CDTSpecial Weather StatementDMX61 min
May 28, 2:31 PM CDTMesoscale DiscussionSPC2 hr
May 29, 3:54 PM CDTMesoscale DiscussionSPC96 min
Jun 6, 3:23 PM CDTSevere Thunderstorm WatchSPC9 hr
Jun 6, 6:08 PM CDTSevere Thunderstorm WarningDMX37 min
Jun 6, 6:20 PM CDTMesoscale DiscussionSPC85 min
Jun 6, 6:43 PM CDTSevere Thunderstorm WarningDMX62 min
Jun 8, 12:51 PM CDTMesoscale DiscussionSPC114 min
Jun 9, 7:05 AM CDTSpecial Weather StatementDMX40 min
Jun 9, 10:17 PM CDTMesoscale DiscussionSPC118 min
Jun 9, 11:44 PM CDTMesoscale DiscussionSPC2 hr
Jun 12, 6:31 PM CDTMesoscale DiscussionSPC2 hr
Jun 14, 3:00 PM CDTHeat AdvisoryDMX4 days
Jun 18, 3:05 PM CDTSevere Thunderstorm WatchSPC6 hr
Jun 18, 3:41 PM CDTFlash Flood WatchDMX16 hr
Jun 18, 5:46 PM CDTMesoscale DiscussionSPC119 min
Jun 20, 1:01 PM CDTMesoscale DiscussionSPC2 hr
Jun 20, 3:04 PM CDTTornado WatchSPC4 hr
Jun 20, 5:13 PM CDTMesoscale DiscussionSPC2 hr
Jun 21, 11:20 AM CDTSpecial Weather StatementDMX3 hr
Jun 27, 3:29 PM CDTHeat AdvisoryDMX54 hr
Jun 30, 2:59 AM CDTFlash Flood WatchDMX27 hr
Jun 30, 3:12 AM CDTHeat AdvisoryDMX16 hr
Jun 30, 7:15 PM CDTMesoscale DiscussionSPC90 min
Jul 3, 2:39 PM CDTHeat AdvisoryDMX29 hr
Jul 11, 3:44 PM CDTHeat AdvisoryDMX28 hr
Jul 13, 4:58 PM CDTSevere Thunderstorm WarningDMX62 min
Jul 15, 6:08 AM CDTDense Fog AdvisoryDMX3 hr
Jul 19, 2:32 PM CDTMesoscale DiscussionSPC118 min
Jul 19, 3:11 PM CDTTornado WatchSPC6 hr
Jul 19, 4:52 PM CDTTornado Warning Tornado observedDMX38 min
Jul 19, 5:12 PM CDTTornado WarningDMX18 min
Jul 19, 5:18 PM CDTMesoscale DiscussionSPC57 min
Aug 5, 6:28 AM CDTSpecial Weather StatementDMX62 min
Aug 5, 5:31 PM CDTSpecial Weather StatementDMX59 min
Aug 5, 5:42 PM CDTSevere Thunderstorm WarningDMX48 min
Aug 5, 5:44 PM CDTMesoscale DiscussionSPC2 hr
Aug 8, 4:23 AM CDTDense Fog AdvisoryDMX5 hr
Aug 25, 3:19 AM CDTDense Fog AdvisoryDMX6 hr
Aug 28, 12:14 PM CDTMesoscale DiscussionSPC2 hr
Aug 28, 4:45 PM CDTMesoscale DiscussionSPC60 min
Aug 28, 5:03 PM CDTSevere Thunderstorm WarningDMX42 min
Aug 28, 5:06 PM CDTSevere Thunderstorm WatchSPC6 hr
Aug 31, 10:55 PM CDTSevere Thunderstorm WarningDMX50 min
Sep 1, 3:35 AM CDTFlash Flood WarningDMX6 hr
Sep 1, 4:38 AM CDTFlash Flood WatchDMX24 hr
Sep 1, 6:34 PM CDTMesoscale DiscussionSPC56 min
Sep 1, 8:20 PM CDTSevere Thunderstorm WatchSPC5 hr
Sep 1, 10:16 PM CDTFlash Flood WarningDMX6 hr
Sep 1, 10:27 PM CDTMesoscale DiscussionSPC63 min
Sep 1, 10:47 PM CDTFlash Flood WarningDMX5 hr
Sep 2, 3:47 AM CDTAreal Flood WarningDMX9 hr
Sep 2, 9:45 AM CDTFlash Flood WatchDMX36 hr
Sep 2, 2:24 PM CDTMesoscale DiscussionSPC2 hr
Sep 3, 5:47 PM CDTMesoscale DiscussionSPC58 min
Sep 3, 6:09 PM CDTTornado WatchSPC2 hr
Sep 3, 6:31 PM CDTSpecial Weather StatementDMX44 min
Sep 3, 6:58 PM CDTTornado WarningDMX32 min
Sep 4, 3:33 AM CDTFlash Flood WatchDMX27 hr
Sep 5, 7:12 AM CDTFlash Flood WatchDMX20 hr
Sep 5, 11:07 AM CDTFlash Flood WarningDMX4 hr
Sep 5, 3:53 PM CDTAreal Flood WarningDMX24 hr
Sep 18, 10:09 AM CDTSpecial Weather StatementDMX81 min
Sep 18, 11:25 AM CDTSpecial Weather StatementDMX65 min
Sep 25, 9:27 AM CDTMesoscale DiscussionSPC2 hr
Sep 25, 11:38 AM CDTSpecial Weather StatementDMX52 min
Sep 25, 1:07 PM CDTMesoscale DiscussionSPC113 min
Oct 3, 12:07 PM CDTWind AdvisoryDMX13 hr
Oct 4, 3:34 PM CDTFlash Flood WatchDMX45 hr
Oct 5, 2:39 PM CDTMesoscale DiscussionSPC3 hr
Oct 7, 3:52 PM CDTFlood WatchDMX60 hr
Oct 8, 9:54 PM CDTSevere Thunderstorm WarningDMX21 min
Oct 8, 10:03 PM CDTTornado WarningDMX15 min
Oct 9, 1:48 AM CDTAreal Flood WarningDMX24 hr
Oct 9, 12:59 PM CDTMesoscale DiscussionSPC3 hr
Oct 9, 1:46 PM CDTTornado WatchSPC7 hr
Oct 9, 3:53 PM CDTMesoscale DiscussionSPC2 hr
Oct 9, 4:21 PM CDTTornado Warning Tornado observedDMX24 min
Oct 9, 4:59 PM CDTTornado WarningDMX31 min
Oct 9, 6:37 PM CDTMesoscale DiscussionSPC83 min
Oct 12, 4:05 PM CDTFrost AdvisoryDMX11 hr
Oct 13, 3:23 PM CDTFreeze WatchDMX23 hr
Oct 14, 3:45 AM CDTFreeze WarningDMX30 hr
Oct 15, 2:44 PM CDTFreeze WarningDMX18 hr
Oct 19, 7:30 PM CDTWind AdvisoryDMX20 hr
Oct 27, 2:24 PM CDTWind AdvisoryDMX23 hr
Nov 3, 4:46 AM CDTDense Fog AdvisoryDMX3 hr
Nov 16, 3:49 AM CSTWinter Weather AdvisoryDMX28 hr
Nov 23, 3:30 AM CSTWinter Storm WatchDMX24 hr
Nov 24, 3:40 AM CSTWinter Storm WarningDMX11 hr
Nov 24, 3:40 AM CSTWinter Weather AdvisoryDMX36 hr
Nov 24, 2:34 PM CSTBlizzard WarningDMX30 hr
Nov 30, 2:34 AM CSTDense Fog AdvisoryDMX7 hr
Dec 1, 6:56 AM CSTWind AdvisoryDMX7 hr
Dec 1, 12:55 PM CSTDense Fog AdvisoryDMX16 hr
Dec 28, 12:55 AM CSTWinter Weather AdvisoryDMX11 hr
Dec 31, 3:26 AM CSTWinter Weather AdvisoryDMX20 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 archive20172019

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.