IEM Daily Bulletin for Aug 23 2025
daryl herzmann
Iowa Environmental Mesonet Daily Bulletin for 23 August 2025
News
Title: TAF Archive Fixes
Date: 22 Aug 07:28 AM
Author: Daryl Herzmann
link
One of the seemingly internet-unique archives that the IEM maintains is a parsed dataset of Terminal Aerodome Forecasts (TAFs). TAFs are issued by the National Weather Service (NWS) as aviation specific short term forecasts at many airports. The raw forecast text looks like:
FTUS43 KMPX 220156 AAA
TAFSTC
TAF AMD
KSTC 220156Z 2202/2224 17005KT P6SM BKN050
TEMPO 2202/2204 -SHRA
FM220400 18005KT P6SM SCT250 PROB30 2210/2215 4SM -TSRA
OVC035CB
FM221500 27010KT P6SM OVC050=
A review of the IEM's TAF processing found some gaps with how the TEMPO and PROB30 fields were stored within the database. These have hopefully now been corrected with an additional field now available within the download called ftype, which delineates between the observation, forecast, tempo, and probability data types.
As always, please send any feedback on this and how the archive could be more useful for your needs!
IEM Code Pushes <repo,branch> on Github
| Timestamp | Repository | Message | Link |
|---|---|---|---|
| Aug 22 10:55 AM | iem,main | 📝 Sundry ARIA/bootstrap5 work | Link |
| Aug 22 11:10 AM | iem,main | 🔥 Drop unused redirect | Link |
| Aug 22 1:03 PM | iem,main | 🚚 Use iemid for RWIS archive stuff refs #1359 |
Link |
| Aug 22 12:20 PM | iem-database,main | ⬆️ Update ruff | Link |
| Aug 22 12:35 PM | iem-database,main | 🐛 Add iemid for RWIS stations refs akrherz/iem#1359 |
Link |
| Aug 22 12:40 PM | iem-database,main | 🐛 Correct indicies | Link |
| Aug 22 1:39 PM | iem-web-services,main | ✨ Support RWIS iemid usage per akrherz/iem#1359 |
Link |
| Aug 22 1:39 PM | iem-web-services,main | ⬆️ Update ruff | Link |
| Aug 22 1:49 PM | iem-web-services,main | ✅ Add test | Link |
Daily Feature
72 Straight at or above 60
Date: 22 Aug 05:30 AM
Votes: Good: 12
Bad: 0 Abstain: 0
While most of the state has seen a sub 60°F temperature recently, the urban heat island of Des Moines has remained at or above that level for 72 straight days. At the time of this feature writing, it is unclear if that streak will continue this Friday morning, but there is metaphysical certitude that the streak will end sometime this weekend and even may make it down into the 40s by early next week. The featured chart presents the longest such streaks for Des Moines. This year's streak will finish as third longest for the site on record.
The featured media can be generated on-demand here
.NWS Watch/Warning Summary for 12 AM 22 Aug 2025 - 12 AM 23 Aug 2025 CDT
| Summary | By WFO | Watches | ||||||
|---|---|---|---|---|---|---|---|---|
| Type | US | IA | ARX | DVN | DMX | OAX | FSD | US |
| Tornado | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Svr Tstorm | 25 | 0 | 0 | 0 | 0 | 6 | 5 | 0 |
| Flash Flood | 16 | 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: 25 Verified: 7 [28.0%] Polygon Size Versus County Size [11.0%] Average Perimeter Ratio [8.4%] Percentage of Warned Area Verified (15km) [15.1%] Average Storm Based Warning Size [940 sq km] Probability of Detection(higher is better) [0.83] False Alarm Ratio (lower is better) [0.72] Critical Success Index (higher is better) [0.27]