Winds aloft . . . again

[DF9AA 0]

On other reasons I had to make two trips on same route with ASA and AS6.5.I noticed a stange phenomena - 3 different winds in all NAV LOGS along the route EGLL-KJFKAll downloaded around Apr25 0930Z within 5 minsEGLL-DIKASASA 147/41 - ASX 143/41 ( which is OK ) and AS6.5 176/35to SHAASA 140/30 slowly changing to 125/10ASX 140/31 abrupt change to 019/08AS6 118/14 changing to 110/17 and later to 020/25to NAT exit point DOGALASA 340-295/around 35ASX 018/8 to 5 ktsAS6 020/25to 53N020W ASA 293/28ASX 018/05AS6 016/20to 52N030WASA 327/52ASX 336/52AS6 317/43to 51N040WASA 290/30ASX 336/52AS6 317/43to 50N050WASA 238/61ASX 229/106 !!!AS6 231/81to YQXASA 275/40-36ASX 000(north)/ 37AS6 355/42from YQX to EBONYASA 357/41ASX 002/48AS6 352/58All readings for FL340Sometimes the differences are not so big, but there are some which influences flightplanning a lot.My question now: Are there 3 sources for the winds - each program uses a different source ? And during flight a 4th source ? Sincenot so seldom I experienced heavy differences up to 180 degrees off the forecast.

[JSkorna 137]

Hi,Pretty sure source is the same, though I could be wrong.Some could be settings and what they do for the data such as virtual stations, enhanced route coverage, and DWC, and internal programming differences between the three programs.Thanks,