I'm not a pilot but downtown AUH at about 16:30 yesterday what I would call a line squall blew in out of nowhere. Vizibility went way down in seconds from flying dust and sand - and I was on the 15th floor. Wind from S-E.
One hour later - all clear.
Same thing as lcmahw experienced ??
Understand this weather system - or whatever it should be correctly called -also affected DXB.