Recent model runs (particularly the 00Z GFS on Sat 28th) indicate a sharp upper trough will arrive over the SW&S-Cape on Tues 31st and Wed 1st, bringing very cold air and some instability. There is still uncertainty as to developments at the surface (mainly the position of the South Atlantic High), but a cold-front will bring some rain to the SW-Cape on Tues 31st. This front seems likely to intensify into a cutoff-low as it moves towards the Eastern Cape coast on Wed 1st, though this low will likely remain weak (or have limited effects on land).
The amounts of rain expected from this event seems limited, but the cold air is likely to bring light snow to all of the coastal mountain ranges on Wed 1st, and possibly reach the Drakensberg by Thurs 2nd. This is nicely shown by the animation on the site snow-forecast.com: www.snow-forecast.com/maps/dynamic/southafrica
This custom GFS chart shows the sharply colder than average temperatures at the 700 hPa level (roughly 3000m altitude) at 00Z on Wed 1st. Other charts are consistent with a freezing level below 1500m along the southern Cape coast for an extended period of time:
Compiled by Gordon Richardson - StormChasingSA
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