IEM Daily Bulletin for Aug 12 2026
daryl herzmann
Iowa Environmental Mesonet Daily Bulletin for 12 August 2026
News
Title: 12 Aug Service Degradation
Date: 12 Aug 06:13 AM
Author: Daryl Herzmann
link
A number of IEM and adjacent services have been degraded this fine Wednesday morning due to a building power outage and unrelated scheduled ISU network maintenance. Accessing the blast radius on all this remains a work in progress, so thank you for your patience and I will update this news item as more is learned!
IEM Code Pushes <repo,branch> on Github
| Timestamp | Repository | Message | Link |
|---|---|---|---|
| Aug 11 8:33 AM | iem,main | 🎨 Rearrange IEMRE sourcing Favoring ECMWF IFS and using it to populate near term estimates of solar radiation and soil temperature. |
Link |
| Aug 11 8:51 AM | iem,main | 💚 Address codereview | Link |
| Aug 11 8:55 AM | iem,main | 🐛 Address wrong navigation | Link |
| Aug 11 11:12 AM | iem,main | 🔥 Deprecate era5land_soilt4_avg climodat var With a shim to calculate it on the fly from max,min cols |
Link |
| Aug 11 12:07 PM | iem,main | 🚚 Update hml shard location | Link |
| Aug 11 12:24 PM | iem,main | 💚 Update default station usage | Link |
| Aug 11 3:45 PM | iem,main | 📝 Sundry rollups | Link |
| Aug 11 3:57 PM | iem,main | 💚 Address codereview | Link |
| Aug 11 4:15 PM | iem,main | 🐛 Fix encoding | Link |
| Aug 11 4:31 PM | iem,main | 🐛 Check for nodata | Link |
| Aug 11 4:47 PM | pywwa,main | ✨ Add fake AFOS entries for canadian SVR/TORs | Link |
| Aug 11 5:05 PM | pywwa,main | 🐛 Set timeout | Link |
| Aug 11 6:01 PM | pywwa,main | 📝 Add WOCN as SPS | Link |
| Aug 11 9:41 AM | iem-database,main | 📝 Unversioned removal of era5land_soilt4_avg The max,min columns are a thing now |
Link |
| Aug 11 9:42 AM | iem-database,main | ⬆️ Update precommits | Link |
| Aug 11 9:44 AM | iem-database,main | [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci |
Link |
| Aug 11 9:52 AM | iem-database,main | 💚 Update test data with min,max columns | Link |
| Aug 11 1:00 PM | iem-database,main | 🐛 Restore IA0200 test data | Link |
Daily Feature
Plenty of CAPE
Date: 11 Aug 05:30 AM
Votes: Good: 16
Bad: 0 Abstain: 2
Atmospheric soundings are an important observational dataset useful for the forecasting the weather. The often twice-daily balloon launches by the National Weather Service capture vertical profiles of temperature, humidity, pressure, and wind. These profiles can be used to compute many useful indices to access the state of the troposphere. Once such index is Convective Available Potential Energy (CAPE), which is useful for understanding how much potential energy is available for near surface air if it were to be lifted vertically and become buoyant. The CAPE index is not necessarily easy to compute and subject to many interpretations and assumptions. The featured chart presents the CAPE index for surface based "parcels" based on soundings from NWS Davenport. The balloon launch Monday evening (00 UTC 11 August 2026) captured a very unstable environment with a CAPE index around 7,700 J/kg. Based on unofficial archives, this was the largest CAPE value for August and one of the largest on record for the site. Large CAPE values are often associated with a "cap" of warm air aloft that prevents storm development, so these environments do not automatically produce severe storms. Generally speaking, CAPE is not a lifting mechanism but an energy reservoir available to support explosive development should air be lifted to levels were it can "freely convect".
The featured media can be generated on-demand here
.NWS Watch/Warning Summary for 12 AM 11 Aug 2026 - 12 AM 12 Aug 2026 CDT
| Summary | By WFO | Watches | ||||||
|---|---|---|---|---|---|---|---|---|
| Type | US | IA | ARX | DVN | DMX | OAX | FSD | US |
| Tornado | 46 | 5 | 0 | 5 | 0 | 0 | 0 | 0 |
| Svr Tstorm | 388 | 15 | 4 | 11 | 0 | 0 | 5 | 10 |
| Flash Flood | 85 | 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: 438 Verified: 219 [50.0%] Polygon Size Versus County Size [27.9%] Average Perimeter Ratio [36.5%] Percentage of Warned Area Verified (15km) [27.2%] Average Storm Based Warning Size [1839 sq km] Probability of Detection(higher is better) [0.80] False Alarm Ratio (lower is better) [0.50] Critical Success Index (higher is better) [0.45]
IEMBot Social Media Posts
IEMBot can be configured to post messages to a number of social media services. More details: IEMBot Homepage.
Posts yesterday per supported service:
- ATMosphere (bluesky only attm): 3,240
- Mastodon / Fediverse: 177
- Slack: 4,009
- Twitter/X: 14,687
- HTTP Webhooks: 476
- Weather.IM Jabber Chatrooms: 27,047