IEM Daily Bulletin for Sep 30 2025

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 30 September 2025

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Sep 29 10:12 PM	iem,main	📝 Sundry updates per review	Link
Sep 25 1:37 PM	iem-database,main	🚀 Update to Postgresql 18 + PostGIS 3.6	Link

Daily Feature

Will Finish Above Average
Date: 29 Sep 05:30 AM
Votes: Good: 10   Bad: 0 Abstain: 0

Even with all of the recent dry weather, the 2025 precipitation total is still set to come in above average. The featured chart presents year to date accumulated precipitation for Ames. The range of observed data is presented along with accumulations for this year, the wettest year (1993) and the driest year (1910). Even if the 2025 total would flat line for the rest of the year, it would still finish above the climatology shown by the dashed line. The forecast this week continues the dry and warm weather with a very warm start to October expected.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 29 Sep 2025 - 12 AM 30 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	1	0	0	0	0	0	0	0
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:   1 Verified:   0 [0.0%]
Polygon Size Versus County Size            [6.0%]
Average Perimeter Ratio                    [0.0%]
Percentage of Warned Area Verified (15km)  [0.0%]
Average Storm Based Warning Size           [1553 sq km]
Probability of Detection(higher is better) [0.00]
False Alarm Ratio (lower is better)        [1.00]
Critical Success Index (higher is better)  [0.00]