In fs 2004 and fsx you can get the current wind/ velocity with pressing shift+ z or shift + y. MSFS does not interpolate the wind and this is notable when you go through another wind layer.
Note that TAS is true airspeed, and is equal to groundspeed without wind.
To find groundspeed with wind, TAS+ or - 1/3 of wind speed if it is from 60 to 90 degrees, 2/3 for 30 to 60 degrees and full for if the wind comes from 30 degrees to your heading. If the wind is from exactly 30 or 60 degrees to your hdg, resp. take 50 and 75 % of wind speed.
Do you have rudder pedals?
Also, note that terrain in MSFS does not resemble the real world a lot, you can get aftermarket terrain but you need a RollsRoyce PC to run it.
Last edited by Da-20 monkey; 30th December 2011 at 15:56.