lead to the temperature gradient between the warm air mass and the cold density current include; hot north-westerly or warm dry foehn wind that precede the squall. Furthermore, severe thunderstorms may come from the forced elevation of warm, humid air. Characteristics The main distinguishing feature of a southerly buster is the sudden, squally southerly change in wind direction which replace the continental northwesterly winds. This is accompanied by a marked temperature drop and sea level pressure rise. Wind gusts in excess of near ground level averages about three per year, which usually come about after very hot days and would tremendously ease within 30 to 60 minutes after the Buster's arrival, becoming rather light within a few hours. A regular southerly buster is between 20 and 60 nautical miles wide, with the heavier winds concentrated on the seaward strip, with its depth being around 1000m, restricted by the height of the mountains to west. An orographic jet, the southerly buster is clearly a mesoscale phenomenon, developing on about one day. Because busters seldom keep a staunch speed while advancing along the coast, its arrival has always been difficult to foretell, though meteorologists nowadays have the gain of satellite imagery and weather radar to foresee it, with wind warning issued by the Bureau of Meteorology. Temperature changes can be dramatic, with falls of 10 to 15 °C (18 to 27 °F) often occurring in a few minutes. In extreme conditions, a southerly buster may lower the temperatures from to . To note, some southerly busters can be mild and not very pronounced, where they would arrive on lukewarm days and even during sultry thunderstorm events, bringing in light, though still noticeably cooler winds in the evening, with its affects still remaining in the following few days as well in some cases. Regions In New South Wales, southerly busters generally reach their maximum intensity between Nowra in the South Coast and Newcastle. Southerly busters rarely pass beyond the Mid North Coast or Port Macquarie – When they do they are usually strengthened by the presence of a tropical cyclone off the north coast of the state. Moreover, they are less pronounced in that region with narrower temperature changes. Not restricted to the immediate coast, southerly busters do generally impinge upon the inland regions of NSW as well, namely the regions in the southeastern block of the state, such as, the Greater Western