IEM Daily Bulletin for Jun 21 2025
daryl herzmann
Iowa Environmental Mesonet Daily Bulletin for 21 June 2025
News
No news is good newsIEM Code Pushes <repo,branch> on Github
| Timestamp | Repository | Message | Link |
|---|---|---|---|
| Jun 20 1:53 PM | iem,main | 🎨 Rewrite VTEC search app https://mesonet.agron.iastate.edu/vtec/search.php |
Link |
| Jun 20 1:54 PM | iem,main | 📝 Modernize more javascript | Link |
| Jun 20 1:59 PM | iem,main | 🐛 Fix date picker usage | Link |
| Jun 20 8:09 PM | iem,main | 🐛 Fix responsive issue hiding columns | Link |
| Jun 20 2:40 PM | iemone,main | 🐛 Simplify webcam window popup placement | Link |
Daily Feature
Windy and Hot
Date: 20 Jun 05:30 AM
Votes: Good: 13
Bad: 1 Abstain: 0
Heat and humidity will be on the rise starting today and lasting into the weekend with heat index values forecast to reach dangerous levels on Saturday and Sunday. Interestingly, winds will be quite strong both days as well, which is somewhat of a rare combination as shown the the featured chart. The chart presents the daily observed frequencies for Des Moines of having a max heat index reading of at least 100°F (red line), a daily max wind gust of at least 30 MPH (green line), and the combined combination of the two on the same day (black line). The combined frequencies are all less than 5% and any non-zero values are just a few percentage points. Having such a combination in mid June is certainly helped by higher observed wind frequencies than during the largest heat index frequencies during July and August.
The featured media can be generated on-demand here
.NWS Watch/Warning Summary for 12 AM 20 Jun 2025 - 12 AM 21 Jun 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 | 106 | 19 | 2 | 1 | 15 | 6 | 7 | 2 |
| Flash Flood | 1 | 1 | 0 | 0 | 1 | 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: 119 Verified: 56 [47.1%] Polygon Size Versus County Size [31.8%] Average Perimeter Ratio [32.0%] Percentage of Warned Area Verified (15km) [17.3%] Average Storm Based Warning Size [2631 sq km] Probability of Detection(higher is better) [0.78] False Alarm Ratio (lower is better) [0.53] Critical Success Index (higher is better) [0.42]