That doesn't meet the WiFi requirement though (easily at least).
He never said "WiFi". He said: "direct wireless connection to the internet" and later clarified that by saying:
"outdoor sensor also transmits data to a wireless receiver ..... that can be connected to the internet via an existing household router"
The Vue or Envoy is certainly a wireless receiver for data from the outdoor sensor. The WeatherLinkIP connects that to the existing household router.
Note: where ..... appears in the quote above, he said "bridge". In context, I consider the WeatherLinkIP to be the bridge.
Of course, there are other solutions involving WiFi, etc. I'm just responding to his (apparent) requirements - wireless connection to a viewable console, and separate wireless connection sending data to "wunderground", without requirement for a PC.