Alert archive / Iowa / Poweshiek County

Weather alerts in Poweshiek County, Iowa, 2016

88 weather alerts in 2016, 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 2016. Tap one for its archive.

Alerts
88
Warnings
12
Watches
14
Advisories
29
Busiest month
June14 alerts
Busiest day
September 19, 20164 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 2 tornado warnings covering Poweshiek County in 2016 had a tornado report inside them; 3 of 3 tornado reports fell inside a warning, on average 14 minutes after it went out.

Poweshiek County, 2016

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings220%3100%14 min
Severe thunderstorm warnings4250%1100%66 min
Flash flood warnings00

Each office's whole area, 2016

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Des Moines, IA: tornado warnings191142%2365%16 min
NWS Des Moines, IA: severe thunderstorm warnings1627951%24665%21 min
NWS Des Moines, IA: flash flood warnings392828%6484%135 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 8, 4:45 AM CSTDense Fog AdvisoryDMX14 hr
Jan 8, 9:45 PM CSTWinter Weather AdvisoryDMX6 hr
Jan 9, 3:55 AM CSTWind Chill AdvisoryDMX32 hr
Jan 11, 3:49 AM CSTWind Chill AdvisoryDMX32 hr
Jan 16, 3:46 PM CSTWind Chill AdvisoryDMX41 hr
Jan 31, 3:19 PM CSTWinter Storm WatchDMX13 hr
Feb 1, 4:21 AM CSTWinter Weather AdvisoryDMX35 hr
Feb 1, 9:50 AM CSTDense Fog AdvisoryDMX5 hr
Feb 1, 7:17 PM CSTDense Fog AdvisoryDMX8 hr
Feb 2, 5:40 PM CSTDense Fog AdvisoryDMX9 hr
Feb 7, 11:18 PM CSTWinter Weather AdvisoryDMX34 hr
Feb 13, 3:58 AM CSTWinter Weather AdvisoryDMX34 hr
Feb 18, 3:48 PM CSTWind AdvisoryDMX26 hr
Feb 19, 8:54 AM CSTHigh Wind WarningDMX6 hr
Mar 13, 10:15 PM CDTDense Fog AdvisoryDMX14 hr
Mar 15, 3:37 AM CDTHigh Wind WatchDMX11 hr
Mar 15, 3:05 PM CDTWind AdvisoryDMX28 hr
Mar 23, 5:10 AM CDTSpecial Weather StatementDMX65 min
Apr 1, 3:37 PM CDTWind AdvisoryDMX24 hr
Apr 3, 4:03 AM CDTWind AdvisoryDMX15 hr
Apr 7, 3:21 PM CDTFreeze WatchDMX12 hr
Apr 8, 3:34 AM CDTFreeze WarningDMX29 hr
Apr 11, 9:42 AM CDTFreeze WarningDMX23 hr
Apr 23, 3:37 AM CDTDense Fog AdvisoryDMX3 hr
May 11, 5:17 AM CDTDense Fog AdvisoryDMX6 hr
May 25, 6:10 AM CDTSpecial Weather StatementDMX65 min
May 28, 12:37 PM CDTMesoscale DiscussionSPC113 min
May 28, 1:37 PM CDTSevere Thunderstorm WatchSPC7 hr
May 28, 5:33 PM CDTMesoscale DiscussionSPC57 min
Jun 1, 3:42 AM CDTDense Fog AdvisoryDMX3 hr
Jun 11, 1:09 AM CDTSpecial Weather StatementDMX51 min
Jun 11, 4:37 AM CDTSpecial Weather StatementDMX53 min
Jun 14, 11:45 AM CDTMesoscale DiscussionSPC2 hr
Jun 14, 2:51 PM CDTMesoscale DiscussionSPC114 min
Jun 14, 3:49 PM CDTMesoscale DiscussionSPC56 min
Jun 14, 7:00 PM CDTMesoscale DiscussionSPC60 min
Jun 14, 8:36 PM CDTMesoscale DiscussionSPC84 min
Jun 21, 10:28 PM CDTMesoscale DiscussionSPC2 hr
Jun 21, 11:18 PM CDTSevere Thunderstorm WatchSPC6 hr
Jun 22, 2:31 AM CDTMesoscale DiscussionSPC119 min
Jun 25, 9:57 PM CDTMesoscale DiscussionSPC3 hr
Jun 26, 1:59 AM CDTSpecial Weather StatementDMX61 min
Jun 30, 1:29 PM CDTMesoscale DiscussionSPC3 hr
Jul 5, 10:35 PM CDTSevere Thunderstorm WatchSPC5 hr
Jul 6, 1:27 AM CDTMesoscale DiscussionSPC2 hr
Jul 6, 2:03 AM CDTSpecial Weather StatementDMX42 min
Jul 7, 12:30 AM CDTMesoscale DiscussionSPC90 min
Jul 7, 12:47 AM CDTSevere Thunderstorm WatchSPC4 hr
Jul 7, 3:52 AM CDTMesoscale DiscussionSPC83 min
Jul 10, 7:34 AM CDTMesoscale DiscussionSPC86 min
Jul 13, 10:33 AM CDTMesoscale DiscussionSPC117 min
Jul 13, 11:14 AM CDTSevere Thunderstorm WatchSPC5 hr
Jul 17, 4:37 AM CDTSpecial Weather StatementDMX53 min
Jul 18, 3:43 PM CDTExcessive Heat WatchDMX36 hr
Jul 19, 4:24 PM CDTExcessive Heat WarningDMX4 days
Jul 22, 2:39 PM CDTMesoscale DiscussionSPC3 hr
Aug 2, 8:21 AM CDTSpecial Weather StatementDMX39 min
Aug 4, 1:28 PM CDTHeat AdvisoryDMX6 hr
Aug 4, 4:44 PM CDTSevere Thunderstorm WatchSPC6 hr
Aug 4, 6:52 PM CDTSevere Thunderstorm WarningDMX68 min
Aug 4, 7:41 PM CDTSevere Thunderstorm WarningDMX64 min
Aug 11, 3:46 AM CDTFlash Flood WatchDMX27 hr
Aug 11, 3:55 PM CDTSevere Thunderstorm WatchSPC7 hr
Aug 11, 6:17 PM CDTMesoscale DiscussionSPC58 min
Aug 11, 9:07 PM CDTMesoscale DiscussionSPC53 min
Aug 19, 8:12 PM CDTSpecial Weather StatementDMX63 min
Aug 24, 7:12 PM CDTSevere Thunderstorm WarningDMX18 min
Sep 6, 3:28 PM CDTFlash Flood WatchDMX31 hr
Sep 19, 2:02 PM CDTMesoscale DiscussionSPC58 min
Sep 19, 2:55 PM CDTTornado WatchSPC4 hr
Sep 19, 4:35 PM CDTSevere Thunderstorm WarningDMX40 min
Sep 19, 5:07 PM CDTMesoscale DiscussionSPC113 min
Sep 21, 2:00 PM CDTMesoscale DiscussionSPC2 hr
Oct 12, 3:53 AM CDTFreeze WarningDMX29 hr
Nov 1, 11:46 PM CDTMesoscale DiscussionSPC2 hr
Nov 15, 3:22 AM CSTDense Fog AdvisoryDMX7 hr
Nov 17, 3:42 PM CSTWind AdvisoryDMX38 hr
Nov 28, 3:53 PM CSTTornado WarningDMX37 min
Nov 28, 4:19 PM CSTTornado Warning Tornado observedDMX41 min
Nov 28, 4:28 PM CSTMesoscale DiscussionSPC92 min
Dec 5, 3:53 AM CSTDense Fog AdvisoryDMX5 hr
Dec 5, 9:10 AM CSTDense Fog AdvisoryDMX81 min
Dec 9, 11:11 AM CSTWinter Weather AdvisoryDMX40 hr
Dec 15, 11:43 AM CSTWinter Weather AdvisoryDMX57 hr
Dec 16, 4:33 AM CSTWind Chill WarningDMX55 hr
Dec 16, 4:33 AM CSTWind Chill AdvisoryDMX55 hr
Dec 18, 2:59 PM CSTWind Chill AdvisoryDMX13 hr
Dec 29, 3:40 AM CSTWind AdvisoryDMX13 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 archive20152017

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.