Yellow clouds of dust and sand shrouded large parts of north and northwest China Friday, the state weather bureau reported, snarling traffic and suffocating locals. "The sixth sandstorm to hit our nation's northern regions struck today, causing the biggest and most wide-ranging storm of the year," the China Meteorological Administration reported on its website.
Visibility dropped to less than 100 metres (330 feet) in parts of Gansu, Ningxia, Xinjiang and Inner Mongolia provinces, where the storms were worst, it said.
Sandstorms frequently blow up in China's arid northern regions as the weather warms in the spring, often sending clouds of yellow dust swirling over South Korea, Japan and as far as the United States.
In Xinjiang, highways were shut down due to the low visibility caused by the storms, while flights in and out of Gansu's tourist oasis of Dunhuang were suspended Friday, press reports said.
EDIT
http://www.terradaily.com/reports/Sandstorms_engulf_north_China_999.html