Storm Chasers / Spotters Database It is an ambition
Things have changed drastically over the past 24 hours on the forecast models. Yesterday we wrote a piece about the weather events likely to impact the Cape over the next week, and mentioned how snow was unlikely. At the time the main global models were showing freezing levels not dropping much below 2000m, though the latest runs show a much more favourable outlook for the snow chasers out there.
Because the models seem to be having a hard time latching onto the moisture and freezing level timings, and the freezing heights – we expect that there may still be wobbles in the forecast and things can go either way at this point, but should the trend continue, it looks like the Western Cape is in for quite a decent snow event starting on Sunday. Because of the developing nature of this forecast, this article will be updated over the next coming days to keep you in the loop about what seems likely.
Update #1 – 28 May 2015 (09:00)
The 00z models show some interesting developments in the way of snow for this coming weekend. Despite previous runs showing freezing level remaining near 2000m, the 00z GFS shows the freezing levels dropping down to 1500m for parts of the Western Cape on Sunday evening into the night. It appears that most of the current forecast snow will fall late on Sunday and into Monday morning, before the freezing level begins to rise again. Snow-Forecast.com’s graphical representation of the snow forecast seems to show quite impressive totals for this period, with potential totals exceeding 20cm in places.
The heaviest snowfall looks confined to the SW Cape mountains, though the models also show the potential for some good amounts further east in the province. Further into the week, the freezing levels currently seem to be too high for the moisture of the front to bring snow to the other provinces of South Africa, though again – this is a developing weather forecast and is subject to possible change at any time.
Stay tuned for more updates as new model runs come in.
Update #2 – 29 May 2015 (09:00)
Recent model runs continue to show impressive amounts of snow for parts of the SW-Cape, though the distribution may change from west (Cederberg) to south (Swartberg) depending on the position of the cold-front, and the exact freezing levels. The freezing levels look even more positive on the 00z run, with a larger area of lower freezing levels extending over a large portion of the Western Cape. If this continues to hold up, we could be looking at quite an impressive snow event.
Towards the end of the period (Wed 3rd and Thurs 4th) snow is possible over parts of the Drakensberg and Lesotho, though the details are hard to predict so far in advance – some of the models are indicating some heavy snowfalls, with the main question at this point being sufficient moisture in association with the freezing levels. Never the less, if the 00z model run were to become reality, it could see very impressive snowfall totals in the Drakensburg range.
Update #3: 1 June 2015 (08:00)
Since the previous update, the weather conditions have been for the most part as expected with snowfalls being reported as early as Sunday morning from Matroosberg Private Nature Reserve. These snowfalls spread throughout the higher mountain peaks of the Western Cape overnight, but freezing levels weren’t as promising as the models predicted on Friday, leading to a limited amount of snow on the lower peaks, because of this any Western Cape snow chasers who are without 4×4 vehicles may need to wait until the next event as there was no ground level snow at Matroosberg. Webcam images from early this morning revealed what appeared to be light snow in Sutherland, however it seemed to have melted due to rain by later in the morning.
The freezing level has already begun to rise, and there should only be light snowfalls experienced on the higher elevation peaks of the Western Cape mountains over the next couple hours before diminishing. However, things are still looking quite promising for other areas of the country later into the week. On Wednesday afternoon when a band of moisture will pass over the Drakensberg area with freezing levels under 3000m. While models indicate heavy snowfalls on the highest peaks during this time, there is the possibility for the band of moisture to be less than forecast, which would result in quite a different scenario – so everything for Wednesday afternoon relies on moisture at this point.
During the period between Tuesday and Thursday, while the focus will be snow for the northern parts, another weather system will be impacting the Western Cape. The focus of the second system, at least for the Western Cape will not be snow but instead the potential for heavy rainfalls. After the fires earlier this year, the Western Cape has not yet been tested with how the affected burn areas will handle a heavy rain event and there is a strong possibility of rockfalls and mudslides in the Cape Town mountain areas that were affected. The second system is a cut-off low pressure system which will be drawing in both cold air from the south and west, while pulling in some warmer tropical air from the north east. This leads to the possibility of thunderstorms and for heavy downpours of rain. It’s difficult to say how bad rainfall will be and which areas will feel it most, but models have been indicating the possibility of more than 30mm of rain on Wednesday.
For the rest of the country, more snowfalls can be expected on Thursday. Yesterday’s models were hinting at some heavy snow possibilities for the Eastern Cape, but the latest 00z indicates less than before, while still showing the distinct possibility for snow in the Eastern Cape. There are a few variables to consider here though, the freezing level is set to drop considerably near the rear end of the moisture band, and this means that the forecast is fickle as should the moisture (which appears to be low amounts) move any quicker, you may see far less snowfall, while on the other hand – if it moves slower it could bring more snow. Snowfalls should clear countrywide by early on Friday morning.
Update #4 – 3 June (08:00)
Snow has began to fall overnight in Lesotho, and is expected to continue over the next at least 30 hours, with the range of snowfall expanding in that time. Currently the snowfall is fairly restricted but this will change soon as the freezing level drops. Most of the current forecast models are suggesting some impressive snow coverage and totals for the Eastern Cape as well tomorrow, where a large area of sub-2000m freezing level will exist. However, it appears that snow will be unlikely anywhere north of Lesotho.
At the same time, some unexpected snowfalls were experienced in Sutherland overnight and into this morning. The models had only hinted at the potential for very light snow in parts of the Northern Cape during the cut-off low, so to see quite a bit of coverage on the webcam came as a surprise.
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