IEM Daily Bulletin for Sep 25 2025
daryl herzmann
Iowa Environmental Mesonet Daily Bulletin for 25 September 2025
News
Title: IEM Archival Update
Date: 24 Sep 11:07 PM
Author: Daryl Herzmann
link
Those of you that follow along with the IEM Github Repository or see the code commits mentioned within the Daily Bulletin Email may be wondering about some recent changes denoting stopping various archival activities. This change probably warrants a news item detailing it, so here we are!
The IEM attempts to archive various meteorological datasets useful for funded research projects that keep the IEM going. These archives include relational databases, flat files on spinning disks / servers at ISU, and files stored within various cloud services Iowa State University has contracts with. Over the years, the IEM took advantage of "unlimited" storage options available at Google and Box to make various archives available within ISU and the public. Sadly, there are no unlimited options left, so a number of archives curated there need to spin down prior to newly enforced quotas set to start off 2026.
The good news is that the vast majority of data you access via the IEM is not impacted by this change, but there are two niche datasets that do have users that will be impacted. The most significant one is the archival of raw MRMS grib data. The other dataset being the archival of satellite imagery generated by the College of DuPage. The mitigation for these two archives is that the MRMS data is now mostly redundantly stored within the AWS Opendata Project and the raw GOES satellite data is stored at AWS as well, so there is a path to regenerate archive plots via that data source.
The IEM just found out about this quota change on Monday (22 September) and have just begun engaging collaborators on what could be done with some of this archived data. Some of the datasets are small enough to come back to live at ISU within current IEM hardware on campus.
To summarize, hopefully impacts to IEM users and projects will be minimal, but some archives will need to be removed or scaled back in scope. As always, please rearch out to daryl with any questions you have!
IEM Code Pushes <repo,branch> on Github
| Timestamp | Repository | Message | Link |
|---|---|---|---|
| Sep 24 9:02 AM | iem,main | 🐛 Account for cache miss | Link |
| Sep 24 11:45 AM | iem,main | 🔥 Discontinue offline daily /archive backup Due to cloud storage removal akrherz/infra#7 , online redundancy remains. |
Link |
| Sep 24 12:26 PM | iem,main | 🔥 Removal of daily webcam lapse archival per cloud storage removal of akrherz/infra#7 , not a huge deal as these are one offs anyway |
Link |
| Sep 24 12:30 PM | iem,main | 🔥 Removal of apache log archival per CyBox removal of akrherz/infra#7 , meh |
Link |
| Sep 24 12:47 PM | iem,main | 📝 Improve coverage | Link |
| Sep 24 2:50 PM | iem,main | 📝 Consolidate IEM MRMS archive info https://mesonet.agron.iastate.edu/archive/mrms.php |
Link |
| Sep 24 2:58 PM | iem,main | 📝 Tweaks per archive updates per akrherz/infra#7 | Link |
| Sep 24 3:12 PM | iem,main | 📝 Improve coverage | Link |
| Sep 24 10:30 PM | iem,main | ✨ Improve legend | Link |
| Sep 24 10:38 PM | iem,main | 📝 Increase coverage | Link |
| Sep 24 12:34 PM | pywwa,main | 📝 Add placeholder for changes | Link |
| Sep 24 12:35 PM | pywwa,main | 🚚 Change archival location per akrherz/infra#7 | Link |
| Sep 24 12:37 PM | pywwa,main | 🚚 Change archival location per akrherz/infra#7 | Link |
| Sep 24 9:16 AM | iem-web-services,main | ⬆️ Update ruff | Link |
| Sep 24 9:16 AM | iem-web-services,main | ⚡️ Share the load | Link |
Daily Feature
Yearly Max SVR Warning Counts
Date: 24 Sep 05:30 AM
Votes: Good: 12
Bad: 0 Abstain: 0
A bit of severe weather visited Iowa on Monday evening, but stayed off to our south on Tuesday. The severe weather threat on Tuesday was focused over eastern Oklahoma and western Arkansas with a number of Severe Thunderstorm (SVR) Warnings issued by the NWS. The NWS office in Norman, Oklahoma issued a few such warnings and added to their prodigious total for the year. In fact, their office's SVR warning total for 2025 is the largest yearly total on record for a NWS forecast office according to unofficial IEM archives. The featured chart presents the top ten NWS forecast office SVR warning total years along with the top years for each of the five offices covering Iowa. If you somehow like Severe Thunderstorm Warnings, central Oklahoma is certainly the place to live with the office having seven of the top ten warning total years. The Iowa office maximums are much smaller in comparison with even the largest total from Sioux Falls being less than half of this year's Norman total.
The featured media can be generated on-demand here
.NWS Watch/Warning Summary for 12 AM 24 Sep 2025 - 12 AM 25 Sep 2025 CDT
| Summary | By WFO | Watches | ||||||
|---|---|---|---|---|---|---|---|---|
| Type | US | IA | ARX | DVN | DMX | OAX | FSD | US |
| Tornado | 4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Svr Tstorm | 23 | 0 | 0 | 0 | 0 | 0 | 0 | 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: 27 Verified: 6 [22.2%] Polygon Size Versus County Size [27.1%] Average Perimeter Ratio [14.4%] Percentage of Warned Area Verified (15km) [10.5%] Average Storm Based Warning Size [1654 sq km] Probability of Detection(higher is better) [0.52] False Alarm Ratio (lower is better) [0.78] Critical Success Index (higher is better) [0.18]