Parameterizing URL query string for data lookup

I have a datasource from the web

= Json.Document(Web.Contents("http://api.weatherstack.com/current?access_key=4d874fb78b08839d1deb2ffc3e6168d2&query=39.6177,-86.1584&units=f"))

I want the query values (long, lat), to be populated from the values in another table. 

I have a parameter named Location, which will be used to look up the long/lat for that location. I want to plug those values into the query string above.

I am not savey enough to figure it out or know exactly what to search for. Any help would be gratley apreciated!