currently I am looking for a self-updating weather stream that I can put into a power point.
At least radar, ideally the temperature itself too.

Any ideas? Currently our IT department is dropping the ball with some powerpoint add-on that isn't working for more than a few minutes at a time.

You can automate powerpoint from within C# using the winapi or other libraries. I would see if you can create the specific slide programmatically and have a C# app running in the background recreating the slide every X minutes.

https://support.microsoft.com/kb/303718/