Update: Cold-front, trough & cutoff-low 26-29 September 2012

This morning's GFS model runs (18Z and 00Z on Mon 24th) show a somewhat weaker upper trough, with a compact but moderately intense cutoff-low centered over Lesotho on Fri 28th and Sat 29th.

This custom GFS chart shows the likely average rainfall (in mm/day) for the 36 hour period from 00Z on Fri 28th to 12Z on Sat 29th. This chart covers much the same time period as that in the one I posted earlier in the thread.

This scenario is still fairly far ahead (5 days or 120 hours), but this morning's GFS model run (06Z on Mon 24th) shows the potential for very heavy snow (above 2400-2600m) on the Drakensberg mountains overnight on Fri 28th into Sat 29th.

Edit: The site snow-forecast.com gives a better view of the likely freezing-levels, and a much better view of the likely snow cover on the underlying terrain map: www.snow-forecast.com/maps/dynamic/southafrica

This custom GFS chart shows the likely precipitation rate (mm/day) during the 12 hours from 18Z on Fri 28th to 06Z on Sat 29th, as well as the likely freezing level at 00Z.

Compiled by Gordon Richardson ( StormchasingSA )