IEM Daily Bulletin for Mar 27 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 27 March 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Mar 26 10:53 AM	iem,main	📝 Sundry updates after log review	Link

Daily Feature

Way below March 2012
Date: 26 Mar 05:30 AM
Votes: Good: 19   Bad: 0 Abstain: 0

Wednesday was yet another rather warm day this March with highs well into the 70s and even a few 80s. A few folks have wondered how this March compares with the benchmark warm March of 2012. The featured chart presents the month to date accumulated average temperature computed over the state of Iowa by the IEM. The black line is 2012, the red line is 2026 and then the spaghetti lines after the 25th represent scenarios appending previous 26-31 March values onto this year's accumulated value to represent a range of possible scenarios. As you can see, even the warmest scenario still comes up about 6 to 7°F (hi kids) degrees short of 2012. It is interesting to see how 2026 did have a lead over 2012 up until the Ides of March, but the second half of March 2012 was exceptionally warm.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 26 Mar 2026 - 12 AM 27 Mar 2026 CDT

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	8	0	0	0	0	0	0	1
Svr Tstorm	70	1	0	2	0	0	0	1
Flash Flood	2	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:  78 Verified:  42 [53.8%]
Polygon Size Versus County Size            [42.3%]
Average Perimeter Ratio                    [37.2%]
Percentage of Warned Area Verified (15km)  [28.9%]
Average Storm Based Warning Size           [1829 sq km]
Probability of Detection(higher is better) [0.82]
False Alarm Ratio (lower is better)        [0.46]
Critical Success Index (higher is better)  [0.48]

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