IEM Daily Bulletin for Nov 26 2025

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 26 November 2025

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Nov 25 10:15 PM	iem,main	✨ Add WindAdv/HighWindWarn Option https://mesonet.agron.iastate.edu/plotting/auto/?q=232	Link
Nov 25 10:59 AM	pyiem,main	⬆️ Update ruff	Link
Nov 25 11:26 AM	pyiem,main	🎨 Cleanup/fix generated docs https://akrherz.github.io/pyIEM/	Link
Nov 25 10:34 AM	pywwa,main	📝 Mur pireps	Link
Nov 25 10:34 AM	pywwa,main	⬆️ Update ruff	Link
Nov 25 10:08 PM	iem-database,main	⬆️ Update ruff	Link
Nov 25 10:08 PM	iem-database,main	✅ Add MCW winter test data	Link

Daily Feature

Recent Cedar Rapids Drought
Date: 25 Nov 05:30 AM
Votes: Good: 12   Bad: 0 Abstain: 0

Even with the 2025 growing season completed, the degrading drought situation for Iowa continues to be of concern. Significant rainfalls this fall season have been fickle and some large departures are starting to accumulate. One such example is Cedar Rapids. The featured chart presents trailing 31, 91, and 365 day precipitation departures from average along with the analyzed US Drought Monitor classification underlain over the past two years. The 31 day departures this time of year can be underwhelming as average values are already at meager amounts. So the current 91 and 365 day departures better show the impact of the dry fall as departures have increased over the past month. The fall and spring seasons are an important time for soil moisture recharge, so much of the state will probably need a wet spring season to help make up for the dry end to the growing season this year and dry fall so far.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 25 Nov 2025 - 12 AM 26 Nov 2025 CST

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	3	0	0	0	0	0	0	1
Svr Tstorm	23	0	0	0	0	0	0	0
Flash Flood	1	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:  26 Verified:  16 [61.5%]
Polygon Size Versus County Size            [31.5%]
Average Perimeter Ratio                    [32.0%]
Percentage of Warned Area Verified (15km)  [24.6%]
Average Storm Based Warning Size           [1899 sq km]
Probability of Detection(higher is better) [0.86]
False Alarm Ratio (lower is better)        [0.38]
Critical Success Index (higher is better)  [0.56]