IEM Daily Bulletin for Mar 31 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 31 March 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Mar 30 8:37 AM	iem,main	🐛 Run iem-tc from /var/tmp	Link
Mar 30 9:17 AM	iem,main	💚 Address coverage	Link
Mar 30 8:55 AM	iem-database,main	⬆️ Update precommits	Link
Mar 30 8:55 AM	iem-database,main	✅ Add mpd test data	Link
Mar 30 12:34 PM	iem-web-services,main	🐛 Use module local get_sqlalchemy_conn	Link
Mar 30 12:42 PM	iem-web-services,main	🎨 Use local get_sqlalchemyconn	Link

Daily Feature

March 65+°F Days
Date: 30 Mar 05:30 AM
Votes: Good: 13   Bad: 0 Abstain: 0

Temperatures warmed nicely on Sunday with high temperatures well into the 60s and even low 70s for Iowa. Des Moines reported a high temperature of 68°F, which made for the tenth day this March with a high temperature of at least 65°F. The featured chart presents the number of such days each March for Des Moines. With high temperatures easily above this threshold on Monday and perhaps again for the last day of March on Tuesday, this year will either tie for third or be in third place for the most number of such days. Such days are not a given during March as shown by the many years without a single such day! The chart also nicely shows how much of an outlier March 2012 was, with no other year even close to that year's total.

The featured media can be generated on-demand here

.

NWS Watch/Warning Summary for 12 AM 30 Mar 2026 - 12 AM 31 Mar 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	42	8	0	1	7	0	0	1
Flash Flood	0	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:  35 Verified:  14 [40.0%]
Polygon Size Versus County Size            [26.2%]
Average Perimeter Ratio                    [23.1%]
Percentage of Warned Area Verified (15km)  [20.3%]
Average Storm Based Warning Size           [1216 sq km]
Probability of Detection(higher is better) [0.59]
False Alarm Ratio (lower is better)        [0.60]
Critical Success Index (higher is better)  [0.31]

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): 1,471
• Mastodon / Fediverse: 19
• Slack: 26
• Twitter/X: 8,009
• HTTP Webhooks: 25
• Weather.IM Jabber Chatrooms: 8,853