A few days ago a post was made on Tropical
Last week saw a trough approach the Western Cape from the west with some very cold polar air aloft. It was from an early stage that this system would have the possibility for thunderstorm development, CAPE values were forecast to remain low but there were some positive (well… negative) LI numbers coming out of the model outputs. A thread in the forums was already discussing the system days prior and it wasn’t long until the SAWS had jumped on board in their forecasts for thundershowers for areas of the Western Cape.
Temperatures forecast for both Wednesday and Thursday were too high and the actual temperature recordings were well below that of the forecasts.
Wednesday saw a veil of cirrus and altocumulus cover the sky but with insufficient surface heating it wasn’t enough to create anything too special. But Thursday was a different story, in the late morning to early afternoon hours of Thursday there were reports of some thundershowers from areas along the West Coast which by early to mid afternoon were being experienced in Cape Town and the northern suburbs. It wasn’t until about 3pm when Somerset West would feel these storms.
Twitter was abuzz as usual with Cape Tonians who were excited about the rare Cape thunderstorms they were experiencing, once again much to the annoyance of the Jozi crowd who feel as though thunderstorms are just another daily occurrence, like the rising of the sun.
The storms were definitely interesting and there was a strong presence of CG lightning around the city, which actually lead to some train problems. There were also numerous reports of short bursts of hail around the CBD, Milnerton and southern suburbs areas. I had to make the drive from Somerset West through to Sea Point in the evening and while on the N2 I managed to see the sunset which caught many peoples attention as mammatus reflected the depleting light to the east and the storms began clearing from the west.
As discussed in the previous articles, we are now in Autumn which is our ‘thunderstorm’ period for the Western Cape and the excitement surely isn’t over yet.
The weather around the Cape has been somewhat miserable since this event, though probably more interesting for the weather enthusiasts. A series of strong cold fronts have meant that the weather hasn’t been able to clear since these storms last week and it’s now been a week with less than sunny conditions with a strong cold front on Monday bringing heavy falls to the Cape Town area.
Looking ahead it appears as though we are about to enter a short stint of warmer weather as a potential berg wind develops into next week, but the long range GFS is showing a lot of frontal activity between days 8 and 14 with the inclusion of a strong cut-off low, though at 360 hours out – it is not worth anything more than keeping an eye on. The 06z model run from today 3 May 2012 is also suggesting the possibility of a cut-off low at day 7, which would be mid next week. I will be watching for any model consistency in the forecast.