A wet afternoon and evening is on the way for much of the Illawarra, Sydney and Hunter coastlines. Sydneysiders woke up to a brilliant sunny morning with hopes that it would finally be a dry day. But as cloud moved in during the late morning there are many people pondering whether they should have brought an umbrella to work today. Those hoping to spot the twilight lunar eclipse are nearly certain to be disappointed by cloud cover obscuring their view. Showers have started moving onto the coast between Gosford and Nelson Bay during the late morning, but this is only a taste of what is to come. The convective showers off the NSW coastline are gaining in strength and are expected to move onto the coast possibly as far south as Batemans Bay. The Sydney and Illawarra coastlines should see showers arriving during the afternoon and potentially becoming most widespread during peak hour or in the early evening. Showers will be focussed near the coast, with western parts of Sydney and the Illawarra only seeing the odd shower moving through. The Hunter is likely to be the wettest of the three districts, with showers focussing in this region during the evening with even the chance of some thunderstorms and heavier falls. The reason for the increase in showers this afternoon and evening is the approach of cold air in the upper atmosphere. As this cold air approaches it increases instability in the atmosphere and forces moist ocean air to rise and develop into showers. From tomorrow showers will mostly clear up along the NSW coast as a high pressure system starts to take hold and the upper cold air starts moving out to sea. The high looks like it will be fairly dominant for almost a week, leading to beautiful weather for the Easter Long Weekend.