Areas of fog have swallowed up parts of Melbourne for the fourth morning in a row, with one more to go. It seems like a long time since showers spread across Melbourne on Monday morning with a trough, but those showers have played a key role in the foggy mornings enveloping Melbourne. Since then, a stationary high pressure system has been in the region, leading to light winds and clear skies. The combination of these ingredients is what allows the cool moist air to reach saturation point and produce areas of fog, something that has occurred each morning since Tuesday. Some of the foggiest places this morning were Melbourne Airport, Essendon and Laverton. In these areas people struggled to even glimpse cars and trees only 100 metres away. Saturday morning should be the final foggy morning, across a similar number of suburbs, with some very thick patches once again. The only difference is that it will probably clear slightly quicker due to slightly breezier conditions in the morning mixing the fog with the drier air aloft. On Sunday morning wind will be a bit stronger ahead of a cold front that is due on Monday. This will lead to a final stunning, mostly sunny day on Sunday before the cool air and showers return in time for the start of the working week.