IEM Daily Bulletin for May 30 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 30 May 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
May 29 7:06 PM	iem,main	🎨 Use JSON payload for autoplot timing via syslog	Link
May 29 8:23 PM	iem,main	⚡️ Create workflow to mine telemetry from syslog	Link
May 29 8:32 PM	iem,main	💚 Address codereview	Link
May 29 8:35 PM	iem,main	💚 Address codereview	Link
May 29 8:36 AM	pyiem,main	🎨 Improve exponential_backoff log messages	Link
May 29 8:36 AM	pyiem,main	⬆️ Update ruff precommit	Link
May 29 9:06 AM	pyiem,main	🐛 Account for CNCL as CWA cancellation string	Link
May 29 9:33 AM	pyiem,main	💚 Address codereview	Link
May 29 7:34 PM	pyiem,main	⚡️ Send website_telemetry messages to syslog	Link
May 29 7:44 PM	pyiem,main	💚 Address codereview	Link
May 30 12:23 AM	pyiem,main	🎨 Use dedicated socket for telemetry logging can't use syslog as systemd/journal intercepts	Link
May 30 12:43 AM	pyiem,main	Revert "🎨 Use dedicated socket for telemetry logging" This reverts commit 231dad2604a146b3d1bfe79cf3f6b51b0aabab05.	Link
May 30 12:23 AM	pyiem,main	🎨 Use dedicated socket for telemetry logging can't use syslog as systemd/journal intercepts	Link
May 29 10:35 PM	iem-web-services,main	🎨 Update telemetry write to use pyiem syslog This avoids a complicated direct database write of telemetry as IEM now handles this via syslog.	Link
May 29 10:46 PM	iem-web-services,main	⬆️ Update ruff precommit	Link
May 29 10:47 PM	iem-web-services,main	💚 Install pyiem from github for docker image build	Link
May 29 10:50 PM	iem-web-services,main	💚 Address codereview	Link
May 29 10:52 PM	iem-web-services,main	➕ Add git conda-forge dependency for docker bld	Link
May 30 6:41 AM	iem-web-services,main	📝 Remove legacy doc	Link

Daily Feature

Four Days of 90+°F
Date: 29 May 05:30 AM
Votes: Good: 9   Bad: 0 Abstain: 0

Our early summer warmth continued on Thursday with highs well into the 80s and even a few 90s across Iowa. For Sioux City, Thursday was the fourth consecutive day with a high temperature of at least 90°F. The featured chart looks into the frequency of a given day of the year participating within such a high temperature streak. The side tables list out the earliest and latest such events on record for the site. This year's event ties for sixth earliest. The high temperature for Friday won't be quite as warm, so the streak will end at four days for the site.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 29 May 2026 - 12 AM 30 May 2026 CDT

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	0	0	0	0	0	0	0	0
Svr Tstorm	70	0	0	0	0	0	0	2
Flash Flood	7	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:  67 Verified:  17 [25.4%]
Polygon Size Versus County Size            [23.4%]
Average Perimeter Ratio                    [31.3%]
Percentage of Warned Area Verified (15km)  [9.6%]
Average Storm Based Warning Size           [1596 sq km]
Probability of Detection(higher is better) [0.36]
False Alarm Ratio (lower is better)        [0.75]
Critical Success Index (higher is better)  [0.18]

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): 2,128
• Mastodon / Fediverse: 13
• Slack: 58
• Twitter/X: 7,578
• HTTP Webhooks: 151
• Weather.IM Jabber Chatrooms: 10,031