IEM Daily Bulletin for Jan 4 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 04 January 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Jan 3 6:05 AM	iem,main	🐛 Account for missing data scenario	Link

Daily Feature

No feature posted

NWS Watch/Warning Summary for 12 AM 3 Jan 2026 - 12 AM 4 Jan 2026 CST

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	1	0	0	0	0	0	0	0
Svr Tstorm	10	0	0	0	0	0	0	0
Flash Flood	4	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:  11 Verified:   4 [36.4%]
Polygon Size Versus County Size            [17.9%]
Average Perimeter Ratio                    [12.3%]
Percentage of Warned Area Verified (15km)  [20.4%]
Average Storm Based Warning Size           [866 sq km]
Probability of Detection(higher is better) [0.50]
False Alarm Ratio (lower is better)        [0.64]
Critical Success Index (higher is better)  [0.27]