As the Climate.gov site addressed in their recent El Niño update
Numerous GFS model runs have hinted at the arrival of a powerful cold-front this weekend (Thurs 30th to Sat 2nd). It has taken a long time for the model to settle down, but there has never been any doubt that it would be a significant weather event. Some (but not all) model runs showed snow as far inland as Namaqualand, the southern Free State Province, and the northern Drakensberg, but these have now backed off to cover mostly the high ground in the southern half of South Africa.
The cold-front will arrive late on Thurs 30th, preceded by strong (near-gale force) north-westerly winds along the Cape coastline. Heavy rain (20-30mm) will occur in places around the Cape Metropole overnight into Fri 1st, spreading gradually inland, and along the southern Cape coast.
Edit: The front will be accompanied by a deep cold-core upper-trough, with 700hPa temperatures below 10C pushing quite far inland, and creating favourable conditions for snow. (The image at the top of this article shows predicted conditions at 12Z on Fri 1st).
Following passage of the front, temperatures will drop sharply during the morning of Fri 1st, as the wind swings to south-westerly. Moisture in circulation will be limited, and the precipitation will not be particularly heavy inland.
Snow will fall over the peaks of the SW-Cape during the day, with heavy falls starting at 1800m elevation, and ending the day as a light falls possibly down as low as 1200m.
A light dusting of snow on Table Mountain (late on Fri 1st) has been suggested by the model runs, but it is impossible to confirm this sort of prediction in advance. Snow is also likely over large parts of the Eastern Cape mountain ranges during this event, and possibly the southern Drakensberg as well.