Monday has mostly westerly winds aloft, but a trough stretching to the northwest of El Calafate could shift the winds to the southwest depending on its exact positioning. The primary wave decreases substantially by 17Z, so it’s best to get above FL460 before that time. Wednesday brings excellent updrafts (and precipitation) in the pre-dawn hours, but in the morning hours the winds shift from westerly to southwesterly and then to southerly as a deep trough digs northward across South America. As the winds swing around the updrafts all but disappear. Thursday afternoon brings more clouds and precipitation to El Calafate
