Numerous model runs (GFS and NOGAPS up to 00Z on Tues 25th) are slowly starting to converge, and there is no change to the scenario indicated earlier in this thread.
A cold-front is likely to brush the SW-Cape late on Wed 26th, bringing some rain (5-10mm), and a sharp drop in temperature (again) on Thurs 27th. Conditions will not clear immediately after the front, but will become part of a prolonged period of unsettled (and cold) weather.
As the upper trough passes over Cape Town early on Fri 28th, it will bring some instability, so few rumbles of thunder are possible (along with more showers until Sat 29th).
The cutoff-low will begin intensifying over the central interior of SA later on Fri 28th, and the cold air will have moved across the country by Sat 29th, when the cutoff-low will exit via the south-east coast.
There is still the possibility of snow over the Drakensberg early on Sat 29th, but this depends on the freezing-level being below 3000m (different model runs are still fluctuating this far ahead).
This custom GFS chart shows two interesting features during the morning of Fri 28th (00Z to 12Z). Light snow is possible over the SW-Cape mountains, while heavy rain (>50mm/day) will start over the interior of SA, Lesotho, and parts of the Eastern Cape and KZN.
Compiled by Gordon Richardson ( Stormchasing SA )
No comments:
Post a Comment