A high atmospheric pressure is currently being observed across south-east Australia, including a preliminary new national record measured in Tasmania this morning.

The weather station at Sheffield reported a pressure of 1044.6 hectopascals (hPa) at 10:30am, which if confirmed beats the previous Australian record of 1044.3hPa at Launceston on June 7, 1967.

The potential record is slightly contentious due to changing observation frequencies and techniques between now and 1967.

However, the high looks likely to peak again near 1044hPa early Saturday, providing another opportunity for a record before the system weakens from Sunday.

The abnormal pressure is having a significant impact on the nation's weather, including extreme low overnight temperatures over south-east states and a lengthy stretch of showery days along the eastern seaboard.

Currently where we live it is 18°C but the apparent or feel like temperature has now dipped down to 12.8°C. ( 2:30 pm Thursday 4 July) .