IEM Daily Bulletin for Dec 6 2025
daryl herzmann
Iowa Environmental Mesonet Daily Bulletin for 06 December 2025
News
No news is good newsIEM Code Pushes <repo,branch> on Github
| Timestamp | Repository | Message | Link |
|---|---|---|---|
| Dec 5 7:52 AM | iem,main | 📝 Update mapserv reference for backend | Link |
Daily Feature
Continued Weak La Niña
Date: 05 Dec 05:30 AM
Votes: Good: 13
Bad: 1 Abstain: 1
The featured chart presents monthly average temperature departures for Ames with the monthly Niño 3.4 index values since the start of 2018. The value of this index drives the designation of either La Niña (negative value) or El Niño (positive value) state with values between -1 and 1 considered as "weak". So we have spent much of 2025 in a weak La Niña state with the present forecast not calling any additional strengthening, so remaining weak. Much is made of using this index to make monthly/seasonal scale forecasts for weather over the globe due to the importance of the equatorial Pacific Ocean basin for global atmospheric circulations. As the chart shows, it is certainly not a simple relationship between this index and monthly temperature departures for a location in the center of Iowa!
The featured media can be generated on-demand here
.NWS Watch/Warning Summary for 12 AM 5 Dec 2025 - 12 AM 6 Dec 2025 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.