I wrote a weather forecaster workflow that displays forecasts from Dark Sky or the Weather Underground. This is actually the second iteration; my first was loosely based on David Ferguson's weather workflow, but written in Python. This version is a complete rewrite in Go.
The source, along with installation and setup instructions, is available at it at https://github.com/jason0x43/alfred-weather.The most current release can be found at https://github.com/jason0x43/alfred-weather/releases.