Is there any other effect besides low visibility?
Both seem to show very similar conditions.
Effects from the pilot's perspective are roughly the same. The difference between snow and sand is mostly due to the abrasive effects of sand/dust on rotor blades and especially engines.
A helicopter operating in the desert will have a much shorter engine life from sand erosion of compressor/turbine blades, and shorter main and tail rotor blade life, compared to one operating in the arctic that is physically unaffected by snow crystals. Add to that all the other things sand can abrade and jam up. Desert operations are the harshest environment for aircraft.