Thick fog developed over parts of the southeast on Sunday morning with visibility dropping to 100m.

A high pressure system over the southeast brought clear overnight skies and cool temperatures. This cool air coupled with ample moisture in the lower levels of the atmosphere allowed extensive fog to develop.

In New South Wales, visibility dropped to 100m at Lithgow, Bombala, Bathurst and Armidale, and 150m at Moss Vale and Cooma. The fog didn’t clear until after 9am in some areas. Fog was more patchy in Sydney and only developed in a few suburbs such as Canterbury where visibility fell to 100m around sunrise.

Fog wasn't as widespread in Victoria but was just as dense with visibility of just 100m recorded at East Sale and Latrobe Valley.

Across Bass Strait, Tasmania didn't escape the foggy Sunday morning and was thickest and most widespread in the Midlands were visibility dropped to below 100m at Ross and Melton Mowbrey at 9 o'clock. There were pockets of thick fog along the coast as well with visibility of 300m at Cape Bruny and below 100m at Strahan.

The high will bring similar conditions on Monday morning with a foggy start to the working week likely for parts of the southeast.