Adelaide was blanketed in dust and smoke on Wednesday, as several grass fires burn around the state on a day of high winds and temperatures. CFS reports that the smoke visible from metropolitan Adelaide and the Hills is a result of multiple fires north of Adelaide (see below for individual fire information). MFS reports the smell of smoke will probably persist over Wednesday and into Thursday. A cool change and rain are expected on Thursday. Bureau of Meteorology imagery from midday Wednesday shows dust over Spencer Gulf, which has since reached the CBD. The dust has been whipped up by gusts of up to 70km/h, after several days of extremely hot and dry conditions. "At the moment our soil moisture is worse than Ash Wednesday in 1983," CFS Preparedness operations director Leigh Miller said. Races at Balaclava were cancelled after jockeys' concerns about the wind and dust. A car accident in the area left several horses with minor injuries, as a driver was unable to see a stopped semi-trailer through the dust. Strong winds and hot conditions fanned a large mulch fire at Jeffries Soils Facility at McEvoy Road, Buckland Park. The fire created huge plumes of smoke which contributed to the haze covering the city. The fire is expected to burn for several days with dozens of firefighters required to contain the blaze on Wednesday evening. There is a risk that the fire will jump containment and spread into surrounding grass lands. A fire near the South Eastern Freeway that blocked traffic is believed to have been deliberately lit. The fire was on the Mount Barker Road, Measdays Ramp to Swanport on the South Eastern Freeway at Leawood Gardens. A total 13 MFS and CFS appliances attended to quickly bring the fire under control. Fire cause investigators attended the scene.