Of all the cloud formations occurring on Table Mountain, the famous ‘tablecloth’ must rank as the most dramatic. In its perfect form, it resembles an immense waterfall pouring over the flat-topped summit. Sometimes it is distorted, appearing as a shapeless bank of cloud stacked up over the summit, dark and forbidding; at other times it creeps over the summit edge like a ghostly veil.
So how does the tablecloth form? This was the subject of much debate among the early Cape inhabitants. They had no way of explaining the phenomenon unfolding in their backyard on a more or less weekly basis during the summer months. All they knew was that the Southeaster had to blow – and blow hard, as it usually does – for the tablecloth to form. Also known as the Cape Doctor (in former times, believed to clear the air of disease; nowadays, its role in ridding the city of smog perpetuates the name), the Southeaster sweeps across the Cape Peninsula from around October through to March. As the prevailing wind in summer, it never brings rain to the Cape, only clear skies and usually the tablecloth. Sometimes the tablecloth is so heavy and dense that it precipitates rain, which is then blown onto the lower slopes of the mountain; on such days, the Southeaster is referred to as a black Southeaster. The tablecloth has its beginnings as moisture-laden air blown in from the Atlantic against the eastern slopes of Table Mountain, where it is forced to rise. The air condenses on contact with the cooler summit air, forming cloud. The cloud is blown over the mountain and down the front, where it dissipates on contact with warmer air at around 500 m above sea level, more or less halfway down Table Mountain.
The tablecloth plays a vital role in sustaining the flora of the summit plateau. In any given year, cloud precipitation on the summit is nearly double the precipitation from rainfall. The many plant species thriving on the summit owe their survival to the tablecloth, which provides them with moisture during the long, dry summer. The leaves and stems of some are uniquely adapted in shape and arrangement to capture the maximum amount of moisture.
With regards to hiking, the tablecloth presents a few challenges and opportunities. The main challenges are lack of visibility (which could get you lost) and drop of temperature, which could lead to hypothermia – a potentially fatal condition. Getting lost on the mountain is easy enough in clear conditions, so when the tablecloth boils up out of nowhere and restricts visibility to a few meters, you better know the way like the back of your hand. Route-finding in the cloud is virtually impossible if you don’t know the mountain, and know it well. Many an unwary hiker over the years have fallen victim to cloud blotting out the landscape in the time it took him to gulp down a sandwich and take a few pictures. But the complications do not end there for our unwary hiker. While the city bakes in the summer heat under a serene sky, the temperature on the dripping, wind-swept and fog-bound summit of Table Mountain approaches freezing. Suffice it to say that the tablecloth is a weather phenomenon to be reckoned with.
As far as opportunities go, the tablecloth can provide the hiker with surreal sights and unique experiences. One of the best has got to be seeing the leading edge of the tablecloth race towards you as you wait for it on the front edge of the summit and then watching it plunge down the sheer cliffs in a graceful arc. Your timing’s got to be impeccable; and even then, the tablecloth might show up in clumps of clouds scudding helter-skelter across the summit. But when it blows in textbook and trim, it makes for a sight that will stay with you for years to come. With Hike Table Mountain, you can experience the beauty and raw energy of the tablecloth up close and in safety.
(c) Riaan Vorster
(c) Riaan Vorster
