Oh no....not the downwind turns thread again......
If i am in an approach with an indicated airspeed of 70 knots and we encounter a tailwind of 70 knots or more for any reason ,i know my ground speed will increase to 140 knots or more.
Really important bit- assuming this is rapid change of wind velocity - how long is going to take for you to recover your groundspeed?
What is going to happen to your airspeed in the meantime...and what could the consequences be?
As DR has said, think inertia/momentum.