IEM Daily Bulletin for Apr 8 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 08 April 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Apr 7 9:18 AM	iem,main	⚡️ Optimize query	Link
Apr 7 10:03 AM	iem,main	🐛 Correct default date	Link
Apr 7 12:58 PM	iem,main	🐛 Correct date input	Link
Apr 7 7:43 PM	iem,main	📝 Sundry updates per review	Link
Apr 7 10:08 PM	pywwa,main	🐛 [shef] Persist converted winds for iemaccess closes #327	Link

Daily Feature

'25-'26 Winter Storm #21
Date: 07 Apr 08:40 AM
Votes: Good: 13   Bad: 0 Abstain: 1

A very narrow band of snow developed overnight and dumped a stripe of an inch or more from about Omaha to Lamoni. The featured map will be updated later today, but totals will be difficult to accurately report as the snow yet falling this Tuesday morning will likely be quickly melting or transitioning to rain. Daytime snowfall events are difficult this late in the cold season as temperatures are typically too warm and even meager sunshine will warm ground surfaces above freezing. The largest report so far is a CoCoRaHS report of 5.5 inches at Creston!

NWS Watch/Warning Summary for 12 AM 7 Apr 2026 - 12 AM 8 Apr 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	4	0	0	0	0	0	0	0
Flash Flood	2	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:   4 Verified:   1 [25.0%]
Polygon Size Versus County Size            [23.2%]
Average Perimeter Ratio                    [1.2%]
Percentage of Warned Area Verified (15km)  [2.7%]
Average Storm Based Warning Size           [3629 sq km]
Probability of Detection(higher is better) [0.50]
False Alarm Ratio (lower is better)        [0.75]
Critical Success Index (higher is better)  [0.20]

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