After a weekend of glorious summer-like conditions, eastern NSW is in for a cool and damp week. Sunday was the hottest day so far this month for many parts of NSW, thanks to a warming airmass and bright, sunny skies. However, cloud and showers developed over the state's southwest during the evening with the arrival of an eastward-moving low pressure trough. By 9am on Monday, Broken Hill and Minindee had picked up 9mm and 2mm respectively, the most they've seen since February. Parts of the Snowy Mountains saw their heaviest falls so far this month. Thredbo picked up 8mm, while Perisher Valley gained 9mm after having its driest start to April in at least three years. During Monday the trough will continue to bring showers and possibly thunderstorms to the state's southeast. A cool southerly change will also make its way up the coast. This change reached the South Coast during Monday morning, meaning places like Merimbula and Bega should see their coolest day so far this month, only reaching the low 20s. This southerly change should reach the Illawarra during the middle of the day, then push through to the Sydney basin in the afternoon and the Hunter Coast in the evening. By Tuesday the change will extend into the Mid North Coast. During Tuesday showers and possibly thunderstorms will affect much of the state's east, mainly along the ranges and between about Wollongong and Port Macquarie. There is potential for more than 40mm in some parts and it will be a cool day, with most places only reaching about 20 degrees. Any rain will be most welcome with much of the southeast so far falling well short of their normal April rainfall. For the remainder of the week there is a chance of showers along the coast each day, with near-average temperatures. For those in the far northeast, showers and storms are possible each day, although a cooler change is not expected in this region until around Friday.