As a reader who is resident of the area and weather-conscious, can say that icing may have been an issue but winds probably not. After a long spell of mild, dry weather we have seen a few snowfalls on those "hills" (mountains really) and for the past three days the snow line has been at about 700 metres above sea level. From what I recall of weather conditions on the morning of the crash, there was probably a lot of cloud between 500 metres and flight level, at least moderate icing but probably nothing unusual in terms of wind or unstable convective cloud. However, that very rapid descent rate does sound like in-flight breakup more than an icing problem, in which case I don't know if icing could have contributed to the break-up if that proves to be the case.