IEM Daily Bulletin for Apr 4 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 04 April 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Apr 3 11:01 AM	iem-database,main	⚡️ Store Cow shared_border_pct SBW stat	Link
Apr 3 11:02 AM	iem-database,main	⬆️ Update ruff	Link
Apr 3 10:37 AM	iem-web-services,main	⬆️ Update ruff	Link
Apr 3 10:38 AM	iem-web-services,main	⚡️ Use ST_ReducePrecision	Link
Apr 3 1:16 PM	iem-web-services,main	🐛 Allow stations with # for bufkit	Link

Daily Feature

Good Start to April
Date: 03 Apr 05:32 AM
Votes: Good: 16   Bad: 0 Abstain: 0

Yesterday's Daily Feature presented a considerable amount of needed precipitation forecast to fall during the first part of April. The first two days of April have lived up to that forecast with much of the state already over an inch. The featured map presents NOAA MRMS precipitation estimates for the first two days of April. These totals will be added to today with multiple rounds of showers and thunderstorms expected.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 3 Apr 2026 - 12 AM 4 Apr 2026 CDT

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	23	2	0	0	0	0	0	2
Svr Tstorm	93	5	0	0	1	3	0	2
Flash Flood	18	1	1	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: 111 Verified:  23 [20.7%]
Polygon Size Versus County Size            [23.5%]
Average Perimeter Ratio                    [24.3%]
Percentage of Warned Area Verified (15km)  [11.8%]
Average Storm Based Warning Size           [1232 sq km]
Probability of Detection(higher is better) [0.87]
False Alarm Ratio (lower is better)        [0.79]
Critical Success Index (higher is better)  [0.20]

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): 1,963
• Mastodon / Fediverse: 45
• Slack: 106
• Twitter/X: 17,867
• HTTP Webhooks: 64
• Weather.IM Jabber Chatrooms: 15,012