Today is a public holiday and a grey rainy day
Today marks the date of the autumnal equinox for the Southern Hemisphere, while the Northern Hemisphere welcome Spring. As far as weather in concerned, this means we can start expecting to see a change in weather patterns that are more associated with the winter months. The summer troughs that bring rainfall to the summer rainfall areas of South Africa will begin to become less abundant, while the high pressure systems which bring summer heat to the southern and western parts of South Africa will become less established, allowing for low pressure systems to have more affect on the weather and bring more rainfall to these areas.
While summer is by no means completely over in this transitional period we can note that this year’s summer has been a mixed bag thus far. We had some severe thunderstorms with a number of tornadoes early in the spring, but as summer came the severe weather remained only moderately noteworthy, at least as far as severe thunderstorms go. The Western Cape saw periods of moderate temperatures between short spells of heatwaves, some of them quite intense and pushing over 40’C in places. While there were some large fires this year in the Western Cape, the usual Table Mountain, Hottentots Holland and Gordon’s Bay mountains got off quite easy (though it remains a year round threat). For the Western Cape and Cape Town area specifically, we are entering our most promising period for thunderstorm development, over the past 7 years the best thunderstorms have all occurred between March and May.
The real interesting talking point this season thus far though, was the tropical activity in the Indian Ocean. Each year there are tropical systems that occur off the far east coast of South Africa, but most of these slip south before ever really being picked up on South Africa’s radar, so to speak. This year was different though and saw several close calls as well as some severe flooding caused. Dando was the first when it’s weak tropical depression remnants moved over Limpopo causing severe flooding. Both Funso and Giovanna peaked the interest of the general public as they came quite close to the South African border. Irina was also a fascinating storm that continued to defy forecasts throughout it’s life, looping around and sparing KZN from a potentially deadly disaster. Though it was enough to bring heavy rains to the province.
In the Northern Hemisphere things were also interesting, naturally this was their winter period, though many in the United States will argue they never felt it. Conditions were very mild in the southern US states this winter with snowfall being somewhat confined to the central plains, north eastern and north western states. Europe also saw a prolonged period of warm weather, though this was broken by a harsh cold snap about a month ago which dumped record snowfall in places.
As Spring approaches in the northern hemisphere it’s time for you storm chasing enthusiasts to pull out the weather models for the USA as they head into tornado season and hurricane season come June. They seem to be entering Spring and Summer ahead of schedule, what this means for tornadoes and hurricanes, we will find out…