IEM Daily Bulletin for Jun 23 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 23 June 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Jun 22 7:12 AM	iem,main	🎨 Prevent sites app usage for metasite stations These have no data, so alas.	Link
Jun 22 7:31 AM	iem,main	🎨 Centralize {precip,snow} str repr	Link
Jun 22 7:45 AM	iem,main	💚 Fixup! Use correct metasite comp	Link
Jun 22 12:50 PM	iem-database,main	🔥 Drop fbndid from flowpath_ofes (unversioned)	Link
Jun 22 12:50 PM	iem-database,main	⬆️ Update ruff precommit	Link
Jun 22 1:00 PM	iem-database,main	💚 Update test data	Link

Daily Feature

IEM 25th Anniversary
Date: 22 Jun 05:30 AM
Votes: Good: 32   Bad: 0 Abstain: 1

The IEM project/website turns 25 years old this summer! Last week, a quasi-surprise celebration was organized by the ISU Agronomy Department (thank you Dr Brian Hornbuckle, Madelynn Wuestenberg, Rita Brueland, and others!) with many long term supporters of the IEM there to share stories and yummy food. The featured image presents yours truly attempting to hold the ice cream cake adorned with the IEM logo toward the camera without it spilling. Collaborators who helped develop the original project along with some of those who find funding support today are shown in the image. The Internet Archive captured how this website looked back on 19 July 2001. Here is to another 25 years

NWS Watch/Warning Summary for 12 AM 22 Jun 2026 - 12 AM 23 Jun 2026 CDT

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	48	0	0	0	0	0	0	0
Svr Tstorm	243	0	0	0	0	0	0	7
Flash Flood	54	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: 287 Verified: 155 [54.0%]
Polygon Size Versus County Size            [26.1%]
Average Perimeter Ratio                    [24.5%]
Percentage of Warned Area Verified (15km)  [24.9%]
Average Storm Based Warning Size           [2021 sq km]
Probability of Detection(higher is better) [0.81]
False Alarm Ratio (lower is better)        [0.46]
Critical Success Index (higher is better)  [0.48]

IEMBot Social Media Posts

IEMBot can be configured to post messages to a number of social media services. More details: IEMBot Homepage.

Posts yesterday per supported service:

• ATMosphere (bluesky only attm): 2,579
• Mastodon / Fediverse: 20
• Slack: 204
• Twitter/X: 12,848
• HTTP Webhooks: 420
• Weather.IM Jabber Chatrooms: 20,258