Showers are likely most days this week in Adelaide but they are unlikely to amount to enough to stop this autumn being the driest in 12 years. Adelaide requires 26 millimetres of rain between now and the end of the month to avoid this being the driest autumn since 2005. However, it looks like falling short despite some rain likely each day from Monday to Thursday and a chance of some more early next week. A low pressure trough and front late on Monday, a front early Wednesday and another front on Thursday will contain little moisture, hence should only bring about 15-to-20mm to the city. Some of that rain is a chance to fall in the form of a briefly intense thunderstorm on Monday evening. So far this season the city has gained 82mm, about 40mm short of the autumn average. Compared to other areas in the state this is not too bad. Much of the state's West Coast has only picked up 15-25mm this season, one-quarter-to-one-third of the autumn average. Elliston has only had 17mm so far, making it their driest autumn in more than 130 years of records. The West Coast town requires about seven more millimetres this month to go ahead of the previous driest on record, set in 1959. One of the state's main moisture sources, the Indian Ocean, has been losing its input since summer and together with a trend away from La Nina, the combination has contributed to a significant drying out.