IEM Daily Bulletin for Sep 15 2025

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 15 September 2025

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Sep 14 5:01 PM	iem,main	📝 Sundry rollups and coverage improvements	Link
Sep 14 11:16 AM	pyiem,main	⚡️ Set libnetcdf,gdal temp pins to help conda solver	Link

Daily Feature

No feature posted

NWS Watch/Warning Summary for 12 AM 14 Sep 2025 - 12 AM 15 Sep 2025 CDT

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	27	0	0	0	0	0	0	1
Svr Tstorm	56	6	0	0	0	12	7	1
Flash Flood	1	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:  83 Verified:  41 [49.4%]
Polygon Size Versus County Size            [20.3%]
Average Perimeter Ratio                    [24.9%]
Percentage of Warned Area Verified (15km)  [22.1%]
Average Storm Based Warning Size           [1278 sq km]
Probability of Detection(higher is better) [0.64]
False Alarm Ratio (lower is better)        [0.51]
Critical Success Index (higher is better)  [0.39]