IEM Daily Bulletin for Aug 9 2025

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 09 August 2025

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Aug 8 2:34 PM	iem,main	📝 Add archive issue note https://mesonet.agron.iastate.edu/request/gis/outlooks.phtml	Link

Daily Feature

Centerville Heavy Rainfall
Date: 08 Aug 05:30 AM
Votes: Good: 11   Bad: 0 Abstain: 0

After a bit of a respite to start August, we are back to where July left off with isolated and near daily heavy rainfall events. On Thursday morning, a training complex of storms dumped heavy rainfall from Des Moines southward to Centerville. The featured map presents a smoothed analysis of available NWS Local Storm Reports, COOP, and CoCoRaHS rainfall totals valid Thursday morning. The 7.3 inch report plotted on the map is near Centerville. The autoplot that generated this map was recently updated to support these rainfall reports. It previously was the app that generated snowfall analysis maps in a similar form.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 8 Aug 2025 - 12 AM 9 Aug 2025 CDT

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	9	0	0	0	0	0	0	0
Svr Tstorm	57	0	0	0	0	0	0	1
Flash Flood	7	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:  65 Verified:  27 [41.5%]
Polygon Size Versus County Size            [37.1%]
Average Perimeter Ratio                    [27.4%]
Percentage of Warned Area Verified (15km)  [13.1%]
Average Storm Based Warning Size           [4334 sq km]
Probability of Detection(higher is better) [0.74]
False Alarm Ratio (lower is better)        [0.58]
Critical Success Index (higher is better)  [0.36]