IEM Daily Bulletin for Jan 16 2026

[daryl herzmann]

Iowa Environmental Mesonet Daily Bulletin for 16 January 2026

News

No news is good news

IEM Code Pushes <repo,branch> on Github

Timestamp	Repository	Message	Link
No code commits found in previous 24 Hours

Daily Feature

Possible 30 Day SPI
Date: 15 Jan 05:30 AM
Votes: Good: 11   Bad: 2 Abstain: 0

The rainfall event last week certainly helped the lingering drought situation left over from the end of the 2025 growing season. Making up precipitation deficits during the driest portion of the year is somewhat difficult, but some precipitation departure metrics have some annual quirks that should be considered. Such a quirk is the subject of today's featured chart. The chart presents a heat map of trailing 30 day standardized precipitation index (SPI) values for Ames. The chart is computed by calculating SPI for each day over the period of record and then plotting a frequency at a given SPI and day of year combination. The colored lines are non-binding US Drought Monitor equivalent SPI values. Since precipitation can not be negative, SPI has minimum possible value since the difference between the average accumulation and zero is some finite number. So the red line points out the annual quirk of this index, which is that it organically improves during the cold season as ac cumulation averages decrease. The chart also nicely shows the spring time decrease (you can visually see the streaking of the frequencies) in SPI as climatology increases daily and individual rainfall events become less impactful over a 30 day period.

The featured media can be generated on-demand here

.

NWS Watch/Warning Summary for 12 AM 15 Jan 2026 - 12 AM 16 Jan 2026 CST

	Summary		By WFO					Watches
Type	US	IA	ARX	DVN	DMX	OAX	FSD	US
Tornado	0	0	0	0	0	0	0	0
Svr Tstorm	0	0	0	0	0	0	0	0
Flash Flood	0	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

No SVR+TOR Warnings Issued.