IEM Daily Bulletin for Apr 26 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 26 April 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Apr 25 3:28 PM	iem,main	📝 Updates per log review	Link
Apr 25 3:28 PM	iem,main	⬆️ Update ruff	Link

Daily Feature

No feature posted

NWS Watch/Warning Summary for 12 AM 25 Apr 2026 - 12 AM 26 Apr 2026 CDT

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	36	0	0	0	0	0	0	3
Svr Tstorm	164	0	0	0	0	9	0	3
Flash Flood	12	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: 190 Verified:  82 [43.2%]
Polygon Size Versus County Size            [23.8%]
Average Perimeter Ratio                    [23.5%]
Percentage of Warned Area Verified (15km)  [28.4%]
Average Storm Based Warning Size           [1079 sq km]
Probability of Detection(higher is better) [0.83]
False Alarm Ratio (lower is better)        [0.57]
Critical Success Index (higher is better)  [0.40]

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): 1,549
• Mastodon / Fediverse: 15
• Slack: 38
• Twitter/X: 15,351
• HTTP Webhooks: 234
• Weather.IM Jabber Chatrooms: 13,232