IEM Daily Bulletin for Jun 13 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 13 June 2026

News

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Daily Feature

Busy Two Days
Date: 12 Jun 05:30 AM
Votes: Good: 10   Bad: 0 Abstain: 0

Thursday picked up where Wednesday left off with two rounds of severe weather impacting Iowa. The first round plowed through the state early Thursday morning bringing strong winds with the storm and even strong winds after the storm passed associated with what is known as a "wake low", more on that with a future IEM feature. The second round developed over southeastern Iowa and pushed off into Illinois by early evening with the most significant severe weather happening outside of the state. The featured screenshot is from the IEM Local Storm Report App showing the combination of storm reports and issued storm warnings by the NWS over Wednesday and Thursday. A new tool was recently added to this app allowing the bean counting of both LSRs and warnings over a rectangle of your choice. Individual warning and report types are counted within this box and shows a large number of events over the past two days. One important item to denote is that LSRs are preliminary, unfiltered, and sometimes contain duplicated reports. So while the LSR total of Tornadoes is shown at 13, this is not an official total number of observed tornadoes over this period!

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 12 Jun 2026 - 12 AM 13 Jun 2026 CDT

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	0	0	0	0	0	0	0	0
Svr Tstorm	149	0	0	0	0	0	0	3
Flash Flood	22	0	0	0	0	0	0	---

ARX = LaCrosse, WI DVN = Davenport, IA DMX = Des Moines, IA OAX = Omaha, NE FSD = Sioux Falls, SD

IEM Cow Report

SVR+TOR Warnings Issued: 146 Verified:  68 [46.6%]
Polygon Size Versus County Size            [19.3%]
Average Perimeter Ratio                    [19.2%]
Percentage of Warned Area Verified (15km)  [21.7%]
Average Storm Based Warning Size           [1234 sq km]
Probability of Detection(higher is better) [0.68]
False Alarm Ratio (lower is better)        [0.53]
Critical Success Index (higher is better)  [0.38]

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