I was driving along in my car on a road near my house today.  The surface wind speeds were about 10-15 mph. Wind direction was roughly the direction I was traveling.  There is a small mountain along this section of road that I know to be 600 feet above the road.  The weather was sunny, partly cloudy.  There was the shadow of a cloud just ahead of me that I tried to clock the speed of.  I was doing 60 mph and it was pulling away from me pretty rapidly.  So, with surface winds at 10-15 mph, only 600 feet up the winds were a lot faster than 60 mph.  Too much for the Phantom to overcome if trying to rth against a headwind, even at a lower altitude.  This is something to keep in mind, and is likely the cause of many a "fly-away".  Even if it is almost dead calm at ground level, if you like to fly high, you have no way of knowing wind speed and direction even just a couple of hundred feet up.

They have yearly competitions here with hot air balloons.  The object is to basically capture the flag.  It requires pretty good control of the direction of the balloon.  I asked one of the pilots how they did that.  He said they change altitudes to find wind that goes in the desired direction.  Different altitudes have different wind speeds and directions.  It can be complicated.

So take care flying your Phantom.  

yes, it would be nice if phantom would report wind speed.. yes, I know, just skip into ATTI mode, I have also noticed that dji app does not seem to report the speed accurately.. according to it i flew well over 60mph on a p3a, not true, not even with the wind....  the log actually does not have those numbers, so the app is doing some extra augmenting of the numbers.. still.. wind is very important and it is quite important to realize that yes, wind speed and direction change significantly with altitude.....