IEM Daily Bulletin for Feb 20 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 20 February 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
Feb 19 1:17 PM	iemone,main	⬆️ Update npm	Link
Feb 19 1:17 PM	iemone,main	🐛 Fix animation whilst in realtime mode fixes #78	Link
Feb 19 1:21 PM	iemone,main	💚 Address unit test failure	Link
Feb 20 5:56 AM	pywwa,main	⬆️ Update precommits	Link
Feb 20 5:56 AM	pywwa,main	🚀 Send FWS to generic parser	Link

Daily Feature

Rare Critical Fire Wx Risk
Date: 19 Feb 05:30 AM
Votes: Good: 13   Bad: 0 Abstain: 0

The Storm Prediction Center (SPC) is most widely known for issuing severe thunderstorm and tornado watches along with convective outlooks. SPC also has a fire weather program with associated fire weather outlooks. For Wednesday, SPC had much of Iowa highlighted with a critical fire weather risk due to strong winds, low humidity, and ample dry surface vegetation. The IEM maintains an unofficial archive of these outlooks and a GIS calculation indicates that the Wednesday critical risk covered more of Iowa than any previous such risk since the beginning of the archive in 2006. The featured chart attempts to show how rare these events are by plotting the yearly duration between the first and last such event that spatially overlapped Iowa by at least 5% of Iowa's area. The right hand side panel plots the number of such events per year. If you run this autoplot with a 50% overlap requirement, you will find only four such events over the period of record including yesterday. This was also the first such event during the month of February for Iowa.

The featured media can be generated on-demand here

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NWS Watch/Warning Summary for 12 AM 19 Feb 2026 - 12 AM 20 Feb 2026 CST

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	33	0	0	0	0	0	0	1
Svr Tstorm	84	0	0	0	0	0	0	0
Flash Flood	4	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: 113 Verified:  34 [30.1%]
Polygon Size Versus County Size            [23.7%]
Average Perimeter Ratio                    [25.6%]
Percentage of Warned Area Verified (15km)  [21.7%]
Average Storm Based Warning Size           [677 sq km]
Probability of Detection(higher is better) [0.58]
False Alarm Ratio (lower is better)        [0.70]
Critical Success Index (higher is better)  [0.25]