Recent model runs continue to show a severe frontal system (though with slightly later arrival) on Fri 31st, and snow extending into Sat 1st. Spring Day will definitely not be on the 1st day of September this year!
Numerous model runs (GFS and NOGAPS 12Z, 18Z and 00Z on Mon 27th) indicate that the freezing level will drop to 1400m over the SW-Cape, with some runs showing the level down to 1200m early on Sat 1st. The freezing level is likely to remain below 1800m for most of the weekend, but lack of moisture will limit snow to the southern Cape coastal mountain ranges (rather than further inland) during Sat 1st. The site snow-forecast.com shows this nicely: www.snow-forecast.com/maps/dynamic/southafrica
The weather over Cape Town is likely to remain unsettled until at least Sun 2nd and Mon 3rd, when another (weaker) cold front may brush the S-Cape coast. After that front, the GFS ensemble (9-12 day outlook) shows a dry spell for the Western Cape from Tues 4th until Fri 8th.
This custom GFS chart shows the possible extent of snow accumulation and freezing-level in the period up to 12Z on Sat 1st. The exact details are likely to change, since this chart is 132 hours (5.5 days) in advance. Note that the GFS model has a rather large grid-size, and very limited terrain detail of the Cape coastal mountain ranges.
Compiled by Gordon Richardson - Stormchasing SA
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