What is the difference between rain and showers?

While we can look outside and say "it is raining", what is rain and what are showers?

Rain comes from clouds that are thick and grey, and often stretch for hundred's of kilometres. Rain is what our farmers like (when it is wanted :) ), as everyone will see it start slowly, increase to a steady fall that lasts for a while before slowly stopping. Rain gives the whole area a soak.

Showers come from different clouds. On a much smaller scale, you see puffy, white cauliflower-like cumulus clouds bubbling up during the hottest part of the day. If they keep growing, they will be tall enough and have heavy enough droplets inside, that a burst of rain falls out. Showers are usually quick and can be quite heavy. The major difference to rain is that they can fall on one part of town while the rest stays dry. They are what I call hit and miss.

Showers also stream in off the ocean, sometimes making it all the way to the northern plains. When there is enough instability and moisture in the air, and winds are onshore, showers will continue until something cuts their energy off or changes the wind direction. This can result in days and days of grey skies and showers on and south of the divide. They are still showers, rather than rain though, because they come through the area pretty quickly.

In a rain system, rainfall amounts are easier to forecast, because everyone, in theory, gets a similar amount. You know it is this sort of system coming when I predict rainfall totals. Showers, on the other hand, are very difficult - in fact, it is very difficult to predict if they will even occur in the first place.

The best scenario for much of inland Victoria to get a good soak is a cloudband picking up moisture from northwestern Australia, and being directed across Victoria from northwest to southeast. Imagine that weather moves on a rollercoaster, up and down in waves - we want it when it is coming downwards to get all the tropical moisture. Also, a couple of days of northeasterly winds before this is great, so that the first drops aren't wasted by falling into dry air and evaporating. This scenario is usually when a surface low pressure system moves just south of Victoria. We get the rain ahead of it, followed by numerous showers from the southwest when it passes.

East Gippsland will miss out though thanks to the alignment of the ranges. The best scenario for East Gippsland to get rain is a low developing just off their coast, sending in both showers and rain in heavy falls.