Alert archive / Iowa / Pocahontas County

Weather alerts in Pocahontas County, Iowa, 2011

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

Pocahontas County and its neighbors

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

Alerts
93
Warnings
18
Watches
14
Advisories
37
Busiest month
July14 alerts
Busiest day
April 10, 201110 alerts

Over time

By month

Warning verification

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

4 of 5 tornado warnings covering Pocahontas County in 2011 had a tornado report inside them; 4 of 5 tornado reports fell inside a warning, on average 34 minutes after it went out.

Pocahontas County, 2011

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings5420%580%34 min
Severe thunderstorm warnings8713%1155%17 min
Flash flood warnings00

Each office's whole area, 2011

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Des Moines, IA: tornado warnings581967%5375%27 min
NWS Des Moines, IA: severe thunderstorm warnings31317444%46874%22 min
NWS Des Moines, IA: flash flood warnings341362%3087%136 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 7, 3:22 PM CSTWinter Weather AdvisoryDMX6 hr
Jan 8, 3:13 PM CSTWinter Storm WatchDMX24 hr
Jan 9, 3:20 PM CSTWinter Weather AdvisoryDMX51 hr
Jan 11, 5:56 PM CSTWind Chill AdvisoryDMX15 hr
Jan 16, 3:38 PM CSTWinter Weather AdvisoryDMX26 hr
Jan 20, 3:46 AM CSTWind Chill AdvisoryDMX30 hr
Jan 29, 4:07 PM CSTWinter Storm WatchDMX12 hr
Jan 30, 4:01 AM CSTWinter Weather AdvisoryDMX68 hr
Feb 1, 4:02 AM CSTWind Chill WarningDMX30 hr
Feb 1, 4:02 AM CSTWind Chill AdvisoryDMX32 hr
Feb 2, 3:09 PM CSTWind Chill AdvisoryDMX18 hr
Feb 7, 3:35 AM CSTWind Chill AdvisoryDMX32 hr
Feb 8, 3:44 PM CSTWind Chill AdvisoryDMX20 hr
Feb 16, 6:00 PM CSTDense Fog AdvisoryDMX16 hr
Feb 19, 4:20 PM CSTWinter Weather AdvisoryDMX17 hr
Mar 8, 4:15 AM CSTWinter Storm WatchDMX11 hr
Mar 8, 3:39 PM CSTWinter Weather AdvisoryDMX18 hr
Mar 11, 3:20 PM CSTWind AdvisoryDMX21 hr
Mar 19, 3:19 AM CDTDense Fog AdvisoryDMX7 hr
Mar 21, 10:05 PM CDTMesoscale DiscussionSPC115 min
Apr 3, 3:47 PM CDTWind AdvisoryDMX26 hr
Apr 9, 5:00 PM CDTMesoscale DiscussionSPC60 min
Apr 9, 5:48 PM CDTTornado WatchSPC7 hr
Apr 9, 9:06 PM CDTMesoscale DiscussionSPC54 min
Apr 9, 9:11 PM CDTTornado WarningDMX49 min
Apr 9, 9:55 PM CDTTornado WarningDMX35 min
Apr 9, 10:22 PM CDTTornado WarningDMX38 min
Apr 9, 10:28 PM CDTTornado WarningDMX47 min
Apr 9, 10:43 PM CDTMesoscale DiscussionSPC62 min
Apr 9, 10:54 PM CDTTornado WarningDMX51 min
Apr 9, 11:01 PM CDTTornado WatchSPC5 hr
Apr 10, 1:26 AM CDTMesoscale DiscussionSPC64 min
Apr 10, 1:38 AM CDTSevere Thunderstorm WarningDMX52 min
May 1, 3:36 PM CDTFrost AdvisoryDMX16 hr
May 2, 3:48 PM CDTFrost AdvisoryDMX15 hr
May 3, 4:05 PM CDTFreeze WarningDMX15 hr
May 15, 3:24 PM CDTFrost AdvisoryDMX16 hr
May 21, 12:51 PM CDTMesoscale DiscussionSPC114 min
May 21, 2:25 PM CDTSevere Thunderstorm WatchSPC10 hr
May 21, 6:07 PM CDTMesoscale DiscussionSPC53 min
May 21, 8:55 PM CDTMesoscale DiscussionSPC65 min
May 25, 4:22 AM CDTWind AdvisoryDMX17 hr
May 30, 3:41 AM CDTWind AdvisoryDMX15 hr
Jun 4, 3:51 AM CDTSevere Thunderstorm WarningDMX39 min
Jun 5, 5:17 PM CDTMesoscale DiscussionSPC88 min
Jun 7, 4:05 AM CDTWind AdvisoryDMX15 hr
Jun 17, 6:44 PM CDTMesoscale DiscussionSPC91 min
Jun 20, 5:55 PM CDTMesoscale DiscussionSPC65 min
Jun 20, 6:53 PM CDTTornado WatchSPC6 hr
Jun 20, 9:02 PM CDTMesoscale DiscussionSPC58 min
Jun 20, 10:19 PM CDTSevere Thunderstorm WarningDMX41 min
Jun 20, 10:22 PM CDTMesoscale DiscussionSPC83 min
Jun 20, 10:57 PM CDTSevere Thunderstorm WarningDMX48 min
Jun 26, 9:46 PM CDTHigh Wind WarningDMX5 hr
Jun 29, 3:44 AM CDTExcessive Heat WatchDMX12 hr
Jun 29, 3:38 PM CDTHeat AdvisoryDMX51 hr
Jul 1, 7:19 PM CDTSevere Thunderstorm WarningDMX41 min
Jul 1, 7:35 PM CDTMesoscale DiscussionSPC55 min
Jul 1, 8:00 PM CDTSevere Thunderstorm WarningDMX45 min
Jul 5, 3:32 PM CDTMesoscale DiscussionSPC88 min
Jul 11, 1:08 AM CDTSevere Thunderstorm WatchSPC13 min
Jul 11, 1:21 AM CDTSevere Thunderstorm WatchSPC4 hr
Jul 11, 2:36 AM CDTMesoscale DiscussionSPC114 min
Jul 14, 3:37 PM CDTExcessive Heat WatchDMX24 hr
Jul 15, 2:21 PM CDTMesoscale DiscussionSPC114 min
Jul 15, 3:32 PM CDTExcessive Heat WarningDMX6 days
Jul 22, 3:00 PM CDTMesoscale DiscussionSPC90 min
Jul 22, 4:12 PM CDTHeat AdvisoryDMX24 hr
Jul 28, 2:47 PM CDTMesoscale DiscussionSPC118 min
Jul 30, 3:47 PM CDTHeat AdvisoryDMX72 hr
Aug 23, 12:45 AM CDTMesoscale DiscussionSPC2 hr
Aug 23, 2:05 AM CDTSevere Thunderstorm WarningDMX55 min
Aug 28, 8:00 AM CDTSevere Thunderstorm WatchSPC5 hr
Aug 28, 10:41 AM CDTMesoscale DiscussionSPC94 min
Aug 31, 3:45 AM CDTDense Fog AdvisoryDMX5 hr
Aug 31, 9:07 AM CDTDense Fog AdvisoryDMX108 min
Sep 2, 3:27 AM CDTMesoscale DiscussionSPC93 min
Sep 2, 3:48 AM CDTSevere Thunderstorm WatchSPC6 hr
Sep 2, 4:27 AM CDTSevere Thunderstorm WarningDMX48 min
Sep 2, 2:41 PM CDTMesoscale DiscussionSPC94 min
Sep 14, 3:52 AM CDTFrost AdvisoryDMX28 hr
Sep 18, 10:54 PM CDTDense Fog AdvisoryDMX10 hr
Sep 28, 3:50 PM CDTWind AdvisoryDMX27 hr
Sep 30, 3:29 PM CDTFrost AdvisoryDMX17 hr
Oct 7, 4:08 AM CDTWind AdvisoryDMX15 hr
Oct 18, 9:30 PM CDTFreeze WarningDMX11 hr
Nov 4, 3:57 PM CDTWind AdvisoryDMX36 hr
Nov 15, 3:25 AM CSTWind AdvisoryDMX14 hr
Nov 19, 10:16 AM CSTWinter Weather AdvisoryDMX5 hr
Nov 25, 3:31 PM CSTWind AdvisoryDMX29 hr
Dec 2, 3:49 AM CSTWinter Storm WatchDMX24 hr
Dec 3, 3:40 AM CSTWinter Weather AdvisoryDMX20 hr
Dec 3, 10:37 AM CSTMesoscale DiscussionSPC5 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.