Williams Island Rain Radar - 100km

Geographical Situation The Sellicks Hill radar is located on top of an escarpment that is part of the southern extension of the Mt Lofty Ranges. The ranges run roughly north to south from Burra to Cape Jervis, while the escarpment on which Sellicks is positioned is locally orientated from northeast to southwest. The radar antenna elevation is approximately 350 metres above sea level. Meteorological aspects Rain-bearing weather systems usually approach from the western half of the skyline, predominantly from the southwest through to the north. The Sellicks Hill radar is ideally situated to detect and track these systems. Shallow rain showers or drizzle on the eastern side of the Mount Lofty Ranges can also be detected, as the radar is not blocked by the ranges themselves. As a "C Band" radar, if there are large thunderstorms around, the radar will not be able to accurately detect the strength of other storms located behind the closest storms. This will also lead to the underestimation of the strength, at times, of very intense isolated storms. Heavy rain over the radar itself will reduce the reliability of the radar in all directions. Non-meteorological echoes In windy conditions, partial beam reflection from waves on Gulf St Vincent (5 km to the west) results in a quasi-permanent weak echo area extending from approximately 315 degrees true to 240 degrees true. This can be distinguished from real echoes, which are smaller in size and usually show steady mobility. The Sellicks Hill radar is increasingly being affected by growth of trees on the surrounding hillside. This growth is blocking the radar beam in areas to the northeast through to the southwest and is most noticeable when the vegetation is wet. Caution should be used when interpreting Sellicks Hill radar in these quadrants and cross-referencing the data against Buckland Park radar imagery is recommended. <a