The IEM processes one minute interval data from ASOS sites via two sources. The near real-time source is the MADIS One Minute ASOS feed which provides data at five minute intervals (confusing eh?). The slightly delayed feed comes from NCEI. Both feeds have been somewhat struggling over the past month, but the MADIS one has been mostly down.
A contact I have at MADIS said that the issue is upstream of them and they continue to actively request a resolution. I'll update this news item once I hear more information about this data feed.
Update 10 Dec 2020: The MADIS data flow appears to be more stable now, but the folks at NCEP IDP are unsure if the upstream issue has been fully resolved or not. They continue to monitor.
Update 14 Dec 2020: The MADIS data flow appears to have stopped again, no updates as to what is happening.
Update 29 Jan 2021: The NCEP IDP folks believe this issue to be resolved.