Much of South Australia, Tasmania, Victoria and New South Wales are being treated so right by the April sun, helping it warm five-to-10 degrees above average, the warmest this late in autumn in several years. Woomera (33.0 degrees), Cleve, (32.3), Snowtown (32.0), Omeo (23.5) and Mt Hotham Airport (19.8) have all had their warmest day this late in the season in 12 years. It has also been the warmest day this late in the season in 10 years in Marree (33.8 degrees) and Roxby Downs (33.5) and seven years in Griffith (30.2), Yanco (30.1), Narrandera (29.9), Cabramurra (17.0) and Eddystone Point (23.0). Winds blowing from the north have combined with the mostly clear skies to bring this warmth and that pattern will last another day or so in Tasmania, Victoria and NSW but come to an end tomorrow in SA. A low pressure trough being fed by moisture from the northwest tropics will cause rain and thunderstorms to slowly spread across SA from Wednesday. Temperatures will drop by as much as 10 degrees as a result of the cloud, rain and storms. The system will weak as it travels east but will still bring patchy rain and a few storms to eastern states from Thursday, leading to cooling. Before the rain arrives some may ask to be taken to the April sun in Cobar - a lovely 29 degrees on Wednesday.