AA, you are quite correct that the rotor will not occur when the forecast wind is for 5 knots. However, I interpret these TAFs in a different way to you, and suspect that the forecaster is trying to show the detachment of the rotor from the hills that moves across the threshold, causing the severe turbulence. Note that the Prob 30 Tempo VRB07 runs exactly during the time period of the 340/25G35 wind forecast so you should read this in conjunction with the basic forecast wind during this period. I have seen the wind trace from the Met Office there showing 35-45kts across followed by a spell of 5 knots wind as the detached rotor moves across the airfield.
Despite this, I agree with you that the movement ban seems to be excessive at the moment. Having also subsequently flown into FNC, I would say that FNC was regularly worse than the conditions at MPA for turbulence, although it is an easy approach at MPA.
Last edited by L1011effoh; 22nd Nov 2018 at 16:46.
Reason: Incorrect assumption removed.