Heavy rain has soaked northern Tasmania, with some places seeing their best May rain in over two decades. A slow-moving low pressure system has been the cause of the rain, most of which has fallen over the past two days. In the 48 hours to 9am this morning, Sheffield collected 115mm, its heaviest rain in two and a half years, and its heaviest for May in at least 17 years. Devonport collected 55mm over the last two days, its heaviest rain in two years and its heaviest for May in 25 years. Totals have been even heavier about the ranges, with Lake Mackenzie picking up 149mm across the last two days, while Fisher River saw 101mm to 9am this morning, the state's highest official figure. While the south managed to see some showers, most places have collected less than 5mm from the system. The low will move rapidly northeast today, causing showers to ease, although parts of the northeast coast should pick up a further 10mm. By Friday, much of the north is likely to be dry, despite a cold front crossing during the afternoon. This will lead into a cold and frosty weekend in the north as skies clear and winds become light as a high pressure ridge moves over the region.