Iowa Environmental Mesonet Daily Bulletin for 29 July 2026

News

No news is good news

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Jul 28 11:54 AM iem,main 🐛 Compute summaries after first filtering Link
Jul 28 12:02 PM iem,main 🐛 Remove the var filling per codereview Link


Daily Feature

2026 RAGBRAI Stats
Date: 28 Jul 05:30 AM
Votes: Good: 16   Bad: 0 Abstain: 1

Held during the last full week of July, RAGBRAI is a seven day bike ride from west to east across Iowa. This year's event finished up this past weekend with most days being rather pleasant for biking and overnight camping. The featured chart presents two weather metrics during each year's ride using the Des Moines airport data as a representative proxy for statewide conditions. Of course a more rigorous weather analysis could be done using more route specific airport station data, but the chart hopefully is a close approximation. The top panel shows the number of hours each year with a heat index of at least 85°F. The bottom panel analyzes wind speed and direction, producing an averaged vector component wind in the east/west direction. For the bottom chart, red values would indicate a net average head wind. So the top panel shows the reduced number of hours with 85+°F heat index vs a long term simple average and even the past three years. The bottom panel as well shows a reduced head winds vs the previous three years.

NWS Watch/Warning Summary for 12 AM 28 Jul 2026 - 12 AM 29 Jul 2026 CDT

Summary By WFO Watches
Type USIA ARXDVNDMXOAXFSD US
Tornado 47 0 0 0 0 0 0 1
Svr Tstorm 297 0 0 0 0 1 0 6
Flash Flood 97 0 0 0 0 1 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: 339 Verified: 156 [46.0%]
Polygon Size Versus County Size            [21.4%]
Average Perimeter Ratio                    [23.8%]
Percentage of Warned Area Verified (15km)  [23.9%]
Average Storm Based Warning Size           [1300 sq km]
Probability of Detection(higher is better) [0.83]
False Alarm Ratio (lower is better)        [0.54]
Critical Success Index (higher is better)  [0.42]

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