IEM Daily Bulletin for Sep 12 2025

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 12 September 2025

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Sep 11 10:07 AM	iem,main	🔥 Drop unused oa-gdd script	Link
Sep 11 10:07 AM	iem,main	📝 Sundry cleanups and coverage improvements	Link
Sep 11 10:56 AM	iem,main	🎨 Add traffic-advice	Link
Sep 11 10:30 PM	iem,main	📝 Sundry review and coverage improvements	Link

Daily Feature

No feature posted

NWS Watch/Warning Summary for 12 AM 11 Sep 2025 - 12 AM 12 Sep 2025 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	31	0	0	0	0	0	0	0
Flash Flood	5	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:  29 Verified:   8 [27.6%]
Polygon Size Versus County Size            [10.6%]
Average Perimeter Ratio                    [15.1%]
Percentage of Warned Area Verified (15km)  [11.2%]
Average Storm Based Warning Size           [1040 sq km]
Probability of Detection(higher is better) [0.33]
False Alarm Ratio (lower is better)        [0.72]
Critical Success Index (higher is better)  [0.18]