You might want to to google for 'raw data' and some name of a global metereological forecast model.
E.g. there are GFS (Global Forecast System) or, in particular, AVN (Aviation Model).
One link I came up with is this one:
http://www.arl.noaa.gov/ready/cmet.html Choose a location (city, ICAO, lat/long) and go for the 'Windgram'. (You need to enter a random code from an image which inhibits large-scale automatic downloads by computers.)
Hope this helps,
EoD