If you’re a Sydneysider, you know the power of a southerly buster. The sudden wintery change that sweeps across a summer city without warning, leaving blustery winds, wild temperature drops and swirling clouds in its wake, is a staple of life in our Harbour City – or, is it?
According to the ABC, Sydney has gone without a classic southerly buster for a record-breaking 14 months. Not to be confused with a southerly wind change, a southerly buster is a very specific weather pattern characterised by a sudden wind reversal, a three-hour temperature drop of five degrees or more, a southerly wind change, the absence of a Tasman low, and wind speeds of at least 54 kilometres per hour.
According to the Bureau of Meteorology, these fronts form when a cold front passes over southeast Australia. They're noticed more acutely by all of us in town on warm days due to the stark contrast between the hot west to north-westerly winds, and the cold, dense air change that hits with the appearance of the southerly buster.
Generally, the good ol’ southerly buster sweeps through Sydney on average five times a year during the warmer months, but right now, we haven’t seen hide nor hair of this big cold front that unceremoniously ruins beach days / makes us all immediately regret not packing a lil’ lightweight jumper in our daypacks. We’ve all been there.
Why haven’t there been any southerly busters in town, you may ask?
Over the last 14 months, Sydney has had an uncommonly cold year (with the most rain ever on record, may we add), and it's believed that the absence of hot days has meant a subsequent absence of southerly busters. Another reason could be the lack of cold fronts that have moved through in the last year or so, with an extended ‘Southern Annular Mode’ meaning our cold fronts have been contracted away from the southern part of the country, into the Southern Ocean. Plus, if the buster decides to move up the coast overnight, the density current won’t be up to scratch to create wind gusts of over 54 kilometres per hour, or temperature drops of five degrees in three hours. Timing, it seems, is everything.
Right now, it doesn’t look like any southerly busters will be making their way down Sydney way anytime soon.
The good news? You can leave your jumpers at home.