IEM Daily Bulletin for Mar 11 2026
daryl herzmann
Iowa Environmental Mesonet Daily Bulletin for 11 March 2026
News
No news is good newsIEM Code Pushes <repo,branch> on Github
| Timestamp | Repository | Message | Link |
|---|---|---|---|
| Mar 10 8:29 AM | iem,main | 🚚 Replace SPC outlook URLs | Link |
| Mar 10 8:50 AM | iem,main | 🎨 Move /json services to single handler | Link |
| Mar 10 10:55 AM | iem,main | 🐛 Review and address GFS 0° Lon issue | Link |
| Mar 10 3:26 PM | iem,main | 🐛 Prevent NaN values in JSON response | Link |
| Mar 10 3:26 PM | iem,main | 📝 Sundry updates per review | Link |
| Mar 10 5:08 PM | iem,main | 💚 Address deepsource concerns | Link |
Daily Feature
Awaiting Last Inch
Date: 10 Mar 05:30 AM
Votes: Good: 8
Bad: 0 Abstain: 0
The spectacular weather on Sunday continued into Monday with record high temperatures set at a number of locations across Iowa and beyond. The calendar says we are still within the second week of March, so there is plenty of time yet for the chance of winter-like weather. The featured chart looks into an aspect of that by plotting the last cold season date of at least an inch of snow reported for Des Moines. The yearly value is plotted along with a line until the date when snow cover was no longer reported (~ how long the snow stuck around). This combination is colorized by the number of days with red values indicating the shortest duration. The left panel black line plots the accumulated frequency of the last date. The 10 March value is somwhere just below 50%, so over half of the previous years on record reported at least a single one inch snowfall event or larger after 10 March. The right hand plot presents the date by year with two trend lines shown. A number of recent years have seen such snows into mid April and even early May, but these late season events struggle to stick around long as ever warming soils, lengthening days, and increased solar inputs act to quickly melt the snow away.
The featured media can be generated on-demand here
.NWS Watch/Warning Summary for 12 AM 10 Mar 2026 - 12 AM 11 Mar 2026 CDT
| Summary | By WFO | Watches | ||||||
|---|---|---|---|---|---|---|---|---|
| Type | US | IA | ARX | DVN | DMX | OAX | FSD | US |
| Tornado | 37 | 3 | 0 | 6 | 0 | 0 | 0 | 6 |
| Svr Tstorm | 223 | 25 | 1 | 33 | 2 | 0 | 0 | 4 |
| Flash Flood | 11 | 0 | 0 | 2 | 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: 244 Verified: 107 [43.9%] Polygon Size Versus County Size [27.5%] Average Perimeter Ratio [31.4%] Percentage of Warned Area Verified (15km) [20.9%] Average Storm Based Warning Size [1498 sq km] Probability of Detection(higher is better) [0.91] False Alarm Ratio (lower is better) [0.56] Critical Success Index (higher is better) [0.42]
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