A series of powerful storms have whipped up winds across the Southwest and southern Plains in the last few weeks, churning up vast clouds of dust that have turned highways into hazard zones. In the last month, at least 20 people have died in car crashes amid low or nonexistent visibility.

The impact of these dust storms stretched beyond the region. Strong winds carried the dust unusually far — hundreds of miles north and east — where it mixed with rain, leaving residents as far as the Mid-Atlantic puzzled by the orange residue coating their cars and homes.

Here’s a look at how a rare combination of drought and strong winds turned a relatively normal late-winter weather event into something far more unusual.

In El Paso, ‘it looks like Mars.’

Dust storms are driven by winds that lift loose dirt up into the air — the drier the land, the less secure the soil.

They occur all over the world, mostly in the Middle East and North Africa. In Europe, it’s not uncommon for fine particles of sand from the deserts of northern Africa to get kicked up by warm, humid Saharan winds that blow from the south or the southeast across the Mediterranean Sea and into southern Europe. That dust can even get dragged as far north as Britain, where it’s sometimes referred to as “blood rain” because of its dirty hue.