IEM Daily Bulletin for Jul 1 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 01 July 2026

News

No news is good news

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Daily Feature

Max June Heat Index
Date: 30 Jun 05:30 AM
Votes: Good: 14   Bad: 0 Abstain: 4

Monday was another steamy hot day with heat index values again over 100°F for most of the state. The featured chart looks into the yearly maximum heat index value for Ames during the month of June. The top panel shows the frequency at or above the given threshold. The bottom panel shows the yearly maximum value for each June. The 2026 value of 106°F (so far) comes in at about a one in five year frequency. There is plenty more hot weather to go this week, but humidity levels are expected to drop a bit to make things a little less insufferable for Tuesday.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 30 Jun 2026 - 12 AM 1 Jul 2026 CDT

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	5	0	0	0	0	0	0	0
Svr Tstorm	149	9	2	0	1	9	7	6
Flash Flood	10	1	0	0	0	1	1	---

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

IEM Cow Report

SVR+TOR Warnings Issued: 150 Verified:  66 [44.0%]
Polygon Size Versus County Size            [29.9%]
Average Perimeter Ratio                    [32.9%]
Percentage of Warned Area Verified (15km)  [18.7%]
Average Storm Based Warning Size           [2147 sq km]
Probability of Detection(higher is better) [0.76]
False Alarm Ratio (lower is better)        [0.56]
Critical Success Index (higher is better)  [0.39]

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