IEM Daily Bulletin for Sep 2 2025

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 02 September 2025

News

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Daily Feature

Summer Ranks
Date: 01 Sep 05:30 AM
Votes: Good: 5   Bad: 0 Abstain: 1

With the calendar turning to September, it is a good time to look back on the summer season that was! The featured map presents IEM unofficial climate district ranks for total precipitation over the June, July, and August months. A value of one would indicate the wettest on record since 1893. There are some large contrasts indicated over the Midwestern US with the most noticeable one over northeastern South Dakota to northern North Dakota or even that of south-central South Dakota! Iowa's summer season was rather wet with only southwestern Iowa indicated to be only slightly above a long term average. The rest of the state was at about the 85th percentile or higher for total precipitation.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 1 Sep 2025 - 12 AM 2 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	34	0	0	0	0	0	0	0
Flash Flood	5	0	0	0	0	2	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:  34 Verified:  13 [38.2%]
Polygon Size Versus County Size            [11.9%]
Average Perimeter Ratio                    [20.6%]
Percentage of Warned Area Verified (15km)  [18.5%]
Average Storm Based Warning Size           [1199 sq km]
Probability of Detection(higher is better) [0.74]
False Alarm Ratio (lower is better)        [0.62]
Critical Success Index (higher is better)  [0.34]