1. Wind speed/direction, air pressure, temperature, humidity, and solar irradiance. We are considering doing atmospheric composition as well, there are a couple of partners that are interested in GHGs, VOCs, water vapor, etc. We have the weight budget to do it, but we haven't flown any production payloads with those sensors yet.

2. The US National Weather Service actually has a commercial data buy program called MESONET [0], where they buy weather data from both academic and commercial partners. We're in the process of becoming one of their commercial partners now. Once we are, a single balloon will pay for itself in a matter of days with the data it can collect, which will let us scale up the number of systems we have deployed. The data we collect right now also lets us build niche weather forecast products like the stratospheric wind forecast mentioned in the post. Once we have enough balloons up, we can start producing useful weather forecast products at a regional and then global scale.

[0]: https://nationalmesonet.us/