This is not such an easy statement to verify. First, we don't see a La Nina impact in the Andes, except maybe right along the equator in Ecuador or Peru, on the teleconnection map for northern winter, that Rebecca provided. We would have to specify just which area in the Central Andes we're talking about. Then we would need to choose a best climate data set, whether temperature or precipitation. Then we would verify the effect of La Nina in the Andes. If the teleconnection map is correct, and we're working south of the equator in the Andes, we should see little or no systematic effect of La Nina.