I had a quick look at GE and see there are some 500 m hills about 6 nm NW of MPA. Are these the hills generating the "rotors"?
Yes, these are the hills generating the rotors. And please, do not think that I am denying that rotor streaming is real, and that it is hazardous.
What I would question is the frequency that hazardous rotor streaming actually occurs, compared to how often it is forecast.
Now that people have absolute clarity regarding their personal responsibilities, we're seeing a weakness in teaching and understanding of Risk Management. Consequently, DDHs may be (are?) being overly risk averse.
Yes, I think that is the problem - but I would have thought it was the responsibility of the Airfield Operator to make the Aircraft Operator aware of the hazard, rather than to mandate the operating limits.
The trouble is that actually, no-one is taking personal responsibility, as the Airport Operator bases the decision on the TAF, and the TAF is based on the computer met model, so in practice, it is all down to what the computer says. The problem is that the computer predicts a P30 severe turbulence any time there is a hint of a Northerly, and in fact, the rotor streaming is a much more rare occurrence.
It comes down to the "Ownership of risk". I am sure that if the ownership of the risk was given to the Aircraft Operator (as the majority of crews I have discussed it with think makes sense), then on a day with the aircraft fuelled, loaded and ready to go, with a 15kt NWesterly with no gusts, and a TAF of P30 tempo severe turbulence, the aircraft would depart, rather than being held for 24 hours, as has happened on more than one occasion.
The comments above about "crippling commercial air transport", and "a reliable air connection" being a priority, hit the nail on the head. Unfortunately the suggestion of having dual operating authorities at MPA is not likely, due to the small size of the civilian administration here. While the airport is nominally a joint civil/military facility, in practice there is not enough traffic to warrant duplicating resources.
Anyway, from the comments above, it does seem that MPA is unique with respect to the Airport Operator setting the met limits, and limits being rigidly based on forecasts rather than actuals.