IEM Daily Bulletin for Sep 12 2026
daryl herzmann
Iowa Environmental Mesonet Daily Bulletin for 12 September 2026
News
No news is good newsIEM Code Pushes <repo,branch> on Github
| Timestamp | Repository | Message | Link |
|---|---|---|---|
| Sep 11 9:03 AM | iem,main | 📝 Sundry PHP updates per review | Link |
| Sep 11 9:09 AM | iem,main | ♻️ Refactor webcam PHP include | Link |
| Sep 11 11:29 AM | iem,main | ⬆️ Update ruff precommit | Link |
| Sep 11 12:05 PM | iem,main | 🎨 Cleanup legacy snet plotting scripts | Link |
| Sep 11 12:53 PM | iem,main | 📝 Address PHP lint whilst reviewing | Link |
| Sep 11 2:08 PM | iem,main | 💚 Address codereview | Link |
| Sep 11 3:12 PM | pywwa,main | 📝 Add CTS6 pirep | Link |
Daily Feature
Days of 80+°F Highs
Date: 11 Sep 05:30 AM
Votes: Good: 0
Bad: 1 Abstain: 0
With high temperatures on Friday expected to reach the lower 80s for much of Iowa and a handful of days over the coming week as warm, it is a good time to check in on the number of days per year with a high temperature of at least 80°F for Ames. The side tables list the top 10 years with the most and least number of days. The bars are colored by their departure from a simple period of record average (black line at 91 days). The 2026 total hasn't quite breached the top 10, but is already well above most years over the past two decades. It is also the seventh consecutive year above average.
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.NWS Watch/Warning Summary for 12 AM 11 Sep 2026 - 12 AM 12 Sep 2026 CDT
| Summary | By WFO | Watches | ||||||
|---|---|---|---|---|---|---|---|---|
| Type | US | IA | ARX | DVN | DMX | OAX | FSD | US |
| Tornado | 3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Svr Tstorm | 74 | 3 | 0 | 0 | 0 | 4 | 4 | 1 |
| Flash Flood | 23 | 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: 75 Verified: 27 [36.0%] Polygon Size Versus County Size [8.3%] Average Perimeter Ratio [24.1%] Percentage of Warned Area Verified (15km) [23.9%] Average Storm Based Warning Size [915 sq km] Probability of Detection(higher is better) [0.82] False Alarm Ratio (lower is better) [0.64] Critical Success Index (higher is better) [0.33]
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