Blown off the runway!

This problem seems to come and go. Whenever I use realtime weather updates it seems that when I am performing a normal takeoff the airplane will either go hard left or hard right on the runway and I simply cannot recover. I tried unplugging the throttle and joystick but the problem persists. Usually I get a little bit of drift on the runway (even with the worst weather conditions) and I can easily compensate for it but now the aircraft simply seems to go out of control. The annoying part is that this problem did not exist a couple of days ago yet it creeps up out of nowhere. What's even more confusing is that the problem goes away if I create my own weather conditions or use clear weather. Any ideas on what's happening here? Thank you.