Iowa Environmental Mesonet Daily Bulletin for 29 October 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp Repository Message Link
Oct 28 5:14 PM iem,main 🎨 Cleanup some pydantic/CGIModel usage Link
Oct 28 9:58 PM iem,main 💚 Address codereview Link
Oct 28 10:10 PM iem,main 🎨 Sundry cleanup Link
Oct 28 10:10 PM iem,main ⬆️ Update ruff precommit Link
Oct 28 1:53 PM pyiem,main 🐛 Cleanup iemapp schema validation Link
Oct 28 2:02 PM pyiem,main ⬆️ Update ruff precommit Link
Oct 28 2:06 PM pyiem,main 💚 Address codereview Link
Oct 28 4:14 PM pyiem,main 🎨 Rework iemapp schema application of datetimes
Need to send strings back through the frontdoor to prevent downstream validation boilerplate.
Link
Oct 28 11:05 PM pyiem,main ✨ Add American Samoa subplot to MapPlot(sector="nws") Link


Daily Feature

Last Week of October Lows
Date: 28 Oct 05:30 AM
Votes: Good: 17   Bad: 0 Abstain: 0

While Tuesday was not as warm as it recently has been, temperatures were still rather mild for most of the state with the exception of northwestern Iowa again for high temperatures. On the other hand, low temperatures were mild for the entire state as significant cold or even freezing temperatures this October have been non-existent except for the brief freeze on the 17th. The featured map looks into the low temperature climatology for the last week of October based on the current official NCEI climatology. On average, low temperatures should be much cooler than they have been with practically all of the state shown in the 30s. The forecast to end October has very little of such chilly temperatures as a number of locations in Iowa will finish the month without a freeze/frost.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 28 Oct 2026 - 12 AM 29 Oct 2026 CDT

Summary By WFO Watches
Type USIA ARXDVNDMXOAXFSD US
Tornado 2 0 0 0 0 0 0 1
Svr Tstorm 20 0 0 0 0 0 0 0
Flash Flood 9 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:  22 Verified:   5 [22.7%]
Polygon Size Versus County Size            [9.4%]
Average Perimeter Ratio                    [18.5%]
Percentage of Warned Area Verified (15km)  [13.8%]
Average Storm Based Warning Size           [841 sq km]
Probability of Detection(higher is better) [0.41]
False Alarm Ratio (lower is better)        [0.77]
Critical Success Index (higher is better)  [0.17]

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