Iowa Environmental Mesonet Daily Bulletin for 31 October 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp Repository Message Link
Oct 30 7:20 AM iem,main ✨ Send Cache-Control for prior year vtec_event requests
Uses the new iemapp(cache_control=...) option from pyIEM#1273 on
/json/vtec_event.py and /geojson/vtec_event.py. Events from a prior
year get public, max-age=86400; current year events get no header.
Co-Authored-By: Claude Opus 5.5 		Link
Oct 30 12:19 PM iem,main 🐛 Correct unsupported tz field being None Link
Oct 30 12:20 PM iem,main ⬆️ Update eslint precommit Link
Oct 30 2:52 PM iem,main 🎨 Address more pandas4 deprecations and typing Link
Oct 30 3:03 PM iem,main ⬆️ Require pandas>=3.1 due to suffixes pain Link
Oct 30 3:04 PM iem,main 💚 Address codereview Link
Oct 30 4:18 PM iem,main ✨ Implement new autoplot internal model approach Link
Oct 30 5:15 PM iem,main 🎨 Use new autoplot plumbing Link
Oct 30 6:43 PM iem,main 🎨 Use updated autoplot params Link
Oct 30 6:44 PM iem,main 🎨 Use new autoplot params Link
Oct 30 6:54 PM iem,main 🎨 Use updated autoplot params Link
Oct 30 6:55 PM iem,main 🎨 Use updated autoplot params Link
Oct 30 6:57 PM iem,main 🎨 Use new autoplot params Link
Oct 30 6:58 PM iem,main 🎨 Use updated autoplot params Link
Oct 30 6:59 PM iem,main 🎨 Use updated autoplot params Link
Oct 30 7:25 PM iem,main 🎨 Use new autoplot params Link
Oct 30 7:48 PM iem,main 💚 Fix test issues Link
Oct 30 9:52 AM pyiem,main 🎨 Account for ambiguous iemapp datetime/tz fields Link
Oct 30 10:08 AM pyiem,main 💚 Address codereview and coverage Link
Oct 30 10:18 AM pyiem,main 💚 Address codereview and type check issue Link
Oct 30 10:32 AM pyiem,main ♻️ Refactor iemapp tz conditioning to preflight Link
Oct 30 10:44 AM pyiem,main 🔥 Remove obsoleted iemapp datetime boilerplate Link
Oct 30 11:21 AM pyiem,main 💥 Remove unsupported TZ_FIELD_OPTIONAL Link
Oct 30 11:21 AM pyiem,main 💚 Continued cleanup on isle 4 for iemapp dt/tz Link
Oct 30 11:27 AM pyiem,main 🔥 Remove now unreachable code Link
Oct 30 11:47 AM pyiem,main 💚 Address codereview Link
Oct 30 12:10 PM pyiem,main 💚 Address codereview and edge cases Link


Daily Feature

Keeping the streak going
Date: 30 Oct 05:30 AM
Votes: Good: 18   Bad: 0 Abstain: 0

The pleasant-for-late-October weather continued on Thursday with highs in the 60s and even low 70s for Iowa. For places like Des Moines, it was the 12th straight day with a high temperature above average. The featured map looks into the current daily high temperature streaks above (red positive numbers) or below (blue negative numbers) average based on the first order NWS CLImate reporting sites. Today's (30 October) high temperatures will struggle to keep the streaks going at a number of locations, but warmer weather is expected again on Saturday and lasting well into next week. Significant cool/cold weather continues to be absent so far this fall season!

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 30 Oct 2026 - 12 AM 31 Oct 2026 CDT

Summary By WFO Watches
Type USIA ARXDVNDMXOAXFSD US
Tornado 0 0 0 0 0 0 0 0
Svr Tstorm 4 0 0 0 0 0 0 0
Flash Flood 21 0 0 0 0 1 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:   4 Verified:   1 [25.0%]
Polygon Size Versus County Size            [1.5%]
Average Perimeter Ratio                    [0.0%]
Percentage of Warned Area Verified (15km)  [14.6%]
Average Storm Based Warning Size           [479 sq km]
Probability of Detection(higher is better) [0.60]
False Alarm Ratio (lower is better)        [0.75]
Critical Success Index (higher is better)  [0.21]

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