It will be one of those weeks where Tasmanians will need sunnies and a hat, followed by a jumper and umbrella. The start of the week will be generally warm, settled and mostly sunny. The mercury will creep up on Tuesday, with Hobart and Launceston tipped to reach 30 degrees or more, which would be the warmest day this month after a extended run of heat during late November. However, a low pressure trough and deep cold front will quickly turn the summer-like conditions around. Later on Tuesday and during Wednesday, the change will see temperatures plummet, gusty winds as well as showers and thunderstorms develop. Temperatures could drop by seven-to-ten degrees as the change moves through. Mild conditions with days in the mid-20's with occasional showers will become the norm for the rest of the week as another front passes on Wednesday, followed by another a few days later.