Why did the US storm bring dirty snow?

The ‘bomb cyclone’ that severed disasters in Minnesota and other upper parts of Mid west dumped in lot of dirt. The freshly falling snow was decolourised. The snow was not the usual pure white. It had lot of dust. The wind picked up lot of dust and dumped it into the circulation of the storm system. Many locals noted the strange colour in the snow.  The cars needed a wash after clearing the snow.

Normally, the part of Minnesota experiences dirty snow. There are other parts of US that experience dirty snow in the South West. However, the dirty snow in these areas is due to the dirt that are in the same area..

But the snow of the ‘bomb cyclone’ brought in the dirt from other parts of the coastal region. Scientists say that the dirt is mainly due to the pollution. It was the second storm after bomb cyclone created havoc last month.