IEM Daily Bulletin for Jun 9 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 09 June 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Jun 8 7:52 AM	iem,main	🎨 Improve docs and limit SPS infographic to 2001+	Link

Daily Feature

Days to accumulate 3 inches
Date: 08 Jun 05:30 AM
Votes: Good: 16   Bad: 0 Abstain: 1

The last four days have seen heavy rainfall events impact portions of Iowa with eastern Iowa receiving the heaviest totals on Sunday. These events are not necessarily widespread and so there can be "unlucky" pockets of the state that miss out on the most significant rainfall totals. One way to compute where these relatively drier pockets are located is to step backwards in time and see how many days it takes to accumulate some threshold of precipitation. For the featured map, the threshold is three inches with precipitation estimates coming from NOAA's MRMS project. This map nicely shows these small areas that have accumulation day totals in the 30 to just over 45 day range, which puts them back into the end of April. There are more chances of significant rainfalls this week, so hopefully some of these isolated areas can have better "luck" with receiving needed rainfall.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 8 Jun 2026 - 12 AM 9 Jun 2026 CDT

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	16	0	0	0	0	0	0	2
Svr Tstorm	171	0	0	0	0	0	0	5
Flash Flood	50	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: 180 Verified:  77 [42.8%]
Polygon Size Versus County Size            [22.6%]
Average Perimeter Ratio                    [29.0%]
Percentage of Warned Area Verified (15km)  [22.9%]
Average Storm Based Warning Size           [1518 sq km]
Probability of Detection(higher is better) [0.80]
False Alarm Ratio (lower is better)        [0.57]
Critical Success Index (higher is better)  [0.39]

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