Sydney will see a dramatic change from this weeks cooler weather with temperatures reaching the mid to upper 30's with hot and gusty northerly winds. Strong and hot northerly winds are developing across much of the interior of the country ahead of a trough, along the south of the country. Those very warm conditions will work their way east and give much of southeast NSW plenty of sunshine and hot summer-like temperatures for Saturday and Sunday. The warm temperatures ahead of the trough are a stark contrast to the cooler conditions over the Bight. The trough will slowly work its way east and be the focal point for areas of strong to severe storms. Those storms will develop over inland areas of NSW Saturday but be more widespread and severe for much of the Blue Mountains and eastern half of NSW during Sunday. The cool southerly change with the trough during Sunday is expected to occur during the mid afternoon in western suburbs and late afternoon across Sydney. The southerly winds will bring an end to temperatures as much as 10-12 degrees above average expected across Sydney for the weekend. Early next week will see a few cooler days with southeasterly winds and showers.