Evaluate migration to the National Weather Service (NWS) API

[deckerego]

Evaluate migration to the National Weather Service (NWS) API. This may resolve #33 #24 #34 and is a cleaner API to integrate with.

[deckerego]

GFS is returning some completely bogus precipitation values - on days with no precip I'm getting 5 - 11 mm/3h

[deckerego]

GFS precip forecast is incredibly wrong - will need to move.