IEM Daily Bulletin for Nov 21 2025
daryl herzmann
Iowa Environmental Mesonet Daily Bulletin for 21 November 2025
News
No news is good newsIEM Code Pushes <repo,branch> on Github
| Timestamp | Repository | Message | Link |
|---|---|---|---|
| Nov 20 3:19 PM | pyiem,main | 🐛 Correct LSR lat/lon parsing for PagoPago + Guam | Link |
| Nov 20 9:06 AM | iem-web-services,main | 🎨 Improve MOS robustness and error messages | Link |
Daily Feature
Cedar Rapids Ceilings
Date: 20 Nov 05:30 AM
Votes: Good: 8
Bad: 1 Abstain: 1
Wednesday was a rather dreary day with overcast skies and drizzle for Iowa. The hourly observations from the Cedar Rapids Airport indicated overcast skies at 800 or lower feet above ground level throughout the day. For aviation, the cloud ceiling represents the level at which the sky is at least 50% covered by clouds as viewed from the ground. While the airport weather station does not explicitly report a ceiling value, an approximation is to find the first level with at least broken clouds reported. The featured chart presents a histogram of calculated ceiling levels for Cedar Rapids by week of the year. Instrumentation and reporting changes over the years makes this plot a bit noisy and please notice the irregular y-axis to capture reporting graduation. The annual signal is rather clear with much higher frequencies of lower ceilings during the cold season. This is due to cooler air being easier to saturate and reduced solar inputs leading to less lower atmospheric mixing, which tends to lower relative humidity.
The featured media can be generated on-demand here
.NWS Watch/Warning Summary for 12 AM 20 Nov 2025 - 12 AM 21 Nov 2025 CST
| Summary | By WFO | Watches | ||||||
|---|---|---|---|---|---|---|---|---|
| Type | US | IA | ARX | DVN | DMX | OAX | FSD | US |
| Tornado | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Svr Tstorm | 12 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Flash Flood | 18 | 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: 14 Verified: 4 [28.6%] Polygon Size Versus County Size [33.7%] Average Perimeter Ratio [22.3%] Percentage of Warned Area Verified (15km) [9.6%] Average Storm Based Warning Size [2086 sq km] Probability of Detection(higher is better) [0.32] False Alarm Ratio (lower is better) [0.71] Critical Success Index (higher is better) [0.18]