IEM Daily Bulletin for Jun 7 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 07 June 2026

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Daily Feature

Incredible Lightning Show
Date: 06 Jun 07:16 AM
Votes: Good: 6   Bad: 0 Abstain: 0

Thunderstorms erupted just before sunset Friday evening over southern Iowa. The storm environment was characterized by high instability and low shear, so the storms did not move very fast and their isolated nature allowed for an incredible viewing of a lightning show. The featured map presents lightning stroke density counts courtesy of Vaisala. The highest totals can be seen just southeast of Des Moines. Even with the marginal shear, they were likely able to produce brief tornadoes. A repeat situation is expected this evening over parts of southern Iowa.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 6 Jun 2026 - 12 AM 7 Jun 2026 CDT

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	12	0	0	0	0	0	0	0
Svr Tstorm	142	3	0	0	2	0	0	7
Flash Flood	45	2	0	0	1	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: 148 Verified:  83 [56.1%]
Polygon Size Versus County Size            [30.8%]
Average Perimeter Ratio                    [30.7%]
Percentage of Warned Area Verified (15km)  [36.0%]
Average Storm Based Warning Size           [2006 sq km]
Probability of Detection(higher is better) [0.85]
False Alarm Ratio (lower is better)        [0.44]
Critical Success Index (higher is better)  [0.51]

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