Alert archive / Iowa / Poweshiek County

Weather alerts in Poweshiek County, Iowa, 2017

91 weather alerts in 2017, 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 2017. Tap one for its archive.

Alerts
91
Warnings
19
Watches
15
Advisories
26
Busiest month
July17 alerts
Busiest day
May 17, 20177 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 1 tornado warnings covering Poweshiek County in 2017 had a tornado report inside them.

Poweshiek County, 2017

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings10100%0
Severe thunderstorm warnings13562%580%29 min
Flash flood warnings00

Each office's whole area, 2017

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Des Moines, IA: tornado warnings251060%1889%9 min
NWS Des Moines, IA: severe thunderstorm warnings27515444%52283%21 min
NWS Des Moines, IA: flash flood warnings9633%1486%248 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 2, 9:54 PM CSTDense Fog AdvisoryDMX4 hr
Jan 10, 9:48 AM CSTWind AdvisoryDMX8 hr
Jan 12, 3:11 PM CSTWinter Storm WatchDMX49 hr
Jan 14, 4:13 PM CSTIce Storm WarningDMX48 hr
Jan 14, 4:13 PM CSTWinter Weather AdvisoryDMX59 hr
Jan 16, 3:59 PM CSTDense Fog AdvisoryDMX13 hr
Jan 18, 9:28 PM CSTDense Fog AdvisoryDMX15 hr
Jan 19, 3:28 PM CSTDense Fog AdvisoryDMX21 hr
Jan 20, 3:31 PM CSTDense Fog AdvisoryDMX20 hr
Jan 21, 3:53 PM CSTDense Fog AdvisoryDMX20 hr
Feb 7, 2:21 AM CSTDense Fog AdvisoryDMX7 hr
Feb 23, 9:48 PM CSTMesoscale DiscussionSPC2 hr
Mar 6, 1:08 PM CSTMesoscale DiscussionSPC3 hr
Mar 6, 1:54 PM CSTTornado WatchSPC8 hr
Mar 6, 3:28 PM CSTFire Weather WatchDMX13 hr
Mar 6, 3:29 PM CSTWind AdvisoryDMX27 hr
Mar 6, 3:35 PM CSTMesoscale DiscussionSPC115 min
Mar 6, 6:11 PM CSTMesoscale DiscussionSPC2 hr
Mar 6, 7:40 PM CSTSevere Thunderstorm WarningDMX54 min
Mar 6, 7:42 PM CSTMesoscale DiscussionSPC63 min
Mar 6, 7:43 PM CSTTornado WarningDMX32 min
Mar 7, 4:00 AM CSTRed Flag WarningDMX14 hr
Mar 12, 4:08 AM CDTWinter Weather AdvisoryDMX31 hr
Mar 19, 11:50 PM CDTMesoscale DiscussionSPC85 min
Mar 25, 10:57 PM CDTDense Fog AdvisoryDMX10 hr
Apr 10, 12:43 AM CDTSevere Thunderstorm WarningDMX36 min
Apr 15, 5:05 PM CDTSevere Thunderstorm WatchSPC7 hr
Apr 15, 7:22 PM CDTMesoscale DiscussionSPC53 min
Apr 15, 7:26 PM CDTSevere Thunderstorm WarningDMX64 min
Apr 15, 8:09 PM CDTSevere Thunderstorm WarningDMX22 min
Apr 18, 2:08 PM CDTFlash Flood WatchDMX19 hr
Apr 19, 8:57 PM CDTSevere Thunderstorm WatchSPC4 hr
Apr 19, 10:06 PM CDTMesoscale DiscussionSPC54 min
May 16, 7:31 PM CDTMesoscale DiscussionSPC59 min
May 16, 8:46 PM CDTSevere Thunderstorm WatchSPC5 hr
May 16, 11:48 PM CDTMesoscale DiscussionSPC117 min
May 17, 12:35 AM CDTSpecial Weather StatementDMX40 min
May 17, 11:39 AM CDTMesoscale DiscussionSPC66 min
May 17, 12:08 PM CDTTornado WatchSPC7 hr
May 17, 4:27 PM CDTSevere Thunderstorm WarningDMX63 min
May 27, 4:12 AM CDTDense Fog AdvisoryDMX6 hr
May 27, 3:55 PM CDTSevere Thunderstorm WarningDMX35 min
Jun 14, 12:06 PM CDTMesoscale DiscussionSPC2 hr
Jun 15, 5:11 PM CDTMesoscale DiscussionSPC64 min
Jun 15, 6:39 PM CDTSevere Thunderstorm WatchSPC6 hr
Jun 15, 9:33 PM CDTMesoscale DiscussionSPC57 min
Jun 15, 11:54 PM CDTSevere Thunderstorm WarningDMX36 min
Jun 16, 7:52 PM CDTSevere Thunderstorm WatchSPC9 hr
Jun 16, 10:26 PM CDTSevere Thunderstorm WarningDMX34 min
Jun 22, 9:09 PM CDTMesoscale DiscussionSPC2 hr
Jun 28, 2:14 PM CDTMesoscale DiscussionSPC2 hr
Jun 28, 2:53 PM CDTTornado WatchSPC9 hr
Jun 28, 5:29 PM CDTMesoscale DiscussionSPC91 min
Jun 29, 9:42 PM CDTSevere Thunderstorm WarningDMX33 min
Jul 3, 1:59 PM CDTSpecial Weather StatementDMX61 min
Jul 10, 1:49 AM CDTMesoscale DiscussionSPC116 min
Jul 10, 2:43 AM CDTMesoscale DiscussionSPC2 hr
Jul 11, 3:35 PM CDTHeat AdvisoryDMX26 hr
Jul 12, 3:33 PM CDTMesoscale DiscussionSPC87 min
Jul 12, 5:55 PM CDTSpecial Weather StatementDMX50 min
Jul 17, 2:58 PM CDTExcessive Heat WatchDMX24 hr
Jul 18, 2:58 PM CDTExcessive Heat WarningDMX4 days
Jul 18, 2:58 PM CDTHeat AdvisoryDMX4 days
Jul 20, 11:06 PM CDTSpecial Weather StatementDMX39 min
Jul 20, 11:29 PM CDTSevere Thunderstorm WarningDMX31 min
Jul 21, 1:32 PM CDTMesoscale DiscussionSPC2 hr
Jul 21, 4:52 PM CDTSevere Thunderstorm WatchSPC9 hr
Jul 21, 6:28 PM CDTMesoscale DiscussionSPC92 min
Jul 21, 8:35 PM CDTMesoscale DiscussionSPC115 min
Jul 21, 11:23 PM CDTMesoscale DiscussionSPC67 min
Jul 26, 3:37 AM CDTFlash Flood WatchDMX17 hr
Aug 10, 3:34 PM CDTSpecial Weather StatementDMX26 min
Aug 10, 3:44 PM CDTSevere Thunderstorm WarningDMX31 min
Aug 18, 4:51 PM CDTSevere Thunderstorm WatchSPC8 hr
Aug 18, 6:58 PM CDTMesoscale DiscussionSPC62 min
Aug 21, 6:58 PM CDTSpecial Weather StatementDMX47 min
Sep 16, 4:21 PM CDTSevere Thunderstorm WarningDMX24 min
Sep 18, 9:56 PM CDTDense Fog AdvisoryDMX12 hr
Sep 21, 4:38 AM CDTSevere Thunderstorm WarningDMX52 min
Sep 22, 10:20 AM CDTHeat AdvisoryDMX9 hr
Oct 27, 4:39 AM CDTFreeze WarningDMX29 hr
Nov 1, 9:53 PM CDTDense Fog AdvisoryDMX11 hr
Nov 12, 9:36 PM CSTDense Fog AdvisoryDMX14 hr
Nov 17, 7:39 PM CSTDense Fog AdvisoryDMX4 hr
Dec 3, 3:41 PM CSTWind AdvisoryDMX39 hr
Dec 5, 4:12 AM CSTWind AdvisoryDMX12 hr
Dec 12, 3:57 PM CSTWind AdvisoryDMX26 hr
Dec 26, 1:53 PM CSTWind Chill AdvisoryDMX20 hr
Dec 28, 3:25 PM CSTWinter Weather AdvisoryDMX30 hr
Dec 29, 3:50 PM CSTWind Chill WarningDMX4 days
Dec 29, 3:50 PM CSTWind Chill AdvisoryDMX38 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 archive20162018

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.