I have a weather driver (info here) where it might be possible to add support for your weather station, as long as it would be a solution of interest to others as well.
With Webrequestor, right now you can extract one value from JSON response data and have it displayed on the device details screen. From there, you could build automations to use that value. But since you have multiple values you are trying to get, it would probably be unreasonably complex to cobble something together.
Otherwise you probably need a custom driver to accomplish what you want; I could possibly look at doing one for you; DM me if you are interested in going down that path.