We are considering a trip to the high Andes of Argentina in the second half of March 2019. We do not have flexibility in dates, and I'm hoping for advice on likely weather conditions. We will be flying to Mendoza and are interested to try a high summit, possibly Mercedario, via the normal route (we are ok with easy glacier travel and altitude acclimatization, but nothing very technical). I understand it is toward the end of the climbing season. Does anyone have experience of climbing Mercedario or other nearby peaks at that time? (We would also consider other targets, eg Aconquija to the north, Tupungato, or lower summits such as Tronador a to the south.) I have heard that 2019 is a predicted El Nino year but I don't know what that means in terms of climbing forecasts. Any advice welcome - thanks.