Heat and humidity levels usually associated with the tropics are bringing muggy and unsettled conditions across Tasmania, Victoria and New South Wales today. Widespread showers and thunderstorms are being driven by a weakening low-pressure system. Severe thunderstorms are likely across large parts of Tasmania, Victoria, and southern NSW, bringing heavy rainfall that may lead to flash flooding, damaging wind gusts and large hail, including the Greater Melbourne and Hobart areas. A cooler westerly