IEM Daily Bulletin for May 12 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 12 May 2026

News

No news is good news

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Daily Feature

Perfect Mothers Day
Date: 11 May 05:30 AM
Votes: Good: 11   Bad: 1 Abstain: 0

It is difficult to imagine the weather on Mothers Day being any better with ample sunshine, a cool breeze, low humidity, and high temperatures around 70°F. The featured chart presents the yearly Mothers Day high temperature as recorded at Des Moines. The previous two years had quite warm temperatures with highs above 80°F, but this year's high of 72°F was just a degree or so above a simple long term average value. While most mothers probably would have preferred it not to rain yesterday, much of the state is starting to need rain again as the growing season is now fully underway and it has been about two weeks since Iowa's most recent widespread and significant rainfall. The near term forecast is not very optimistic about upcoming rainfall events.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 11 May 2026 - 12 AM 12 May 2026 CDT

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	1	0	0	0	0	0	0	0
Svr Tstorm	14	0	0	0	0	0	0	0
Flash Flood	2	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:  15 Verified:   7 [46.7%]
Polygon Size Versus County Size            [31.2%]
Average Perimeter Ratio                    [17.2%]
Percentage of Warned Area Verified (15km)  [17.0%]
Average Storm Based Warning Size           [1824 sq km]
Probability of Detection(higher is better) [0.69]
False Alarm Ratio (lower is better)        [0.53]
Critical Success Index (higher is better)  [0.39]

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