2nd Ld-Writethru: Sandstorms sweep through northern China

A sandstorm swept over much of north China including Beijing on Thursday, turning the sky yellow and obscuring visibility.

The city's meteorological center issued a blue alert for sandstorms Thursday morning, forecasting winds that would carry sand and dust across the capital. Many pedestrians in downtown Beijing were seen wearing protective masks.

Most monitoring stations in the city showed PM10 readings of more than 1,000 micrograms per cubic meter and PM2.5 readings of over 400 micrograms per cubic meter as of Thursday at noon, according to data from Beijing Municipal Environmental Monitoring Center.

Visibility plummeted to as low as one kilometer in many parts of Beijing and is expected to fall further.

According to the Beijing Times, more than 40 flights at Beijing Capital Airport were delayed due to the sandstorm, with another 15 canceled.

Neighboring Tianjin Municipality was also hit by dust and sand, which darkened the sky and effected traffic flow.

"The sky turned gray and the smell of dust and sand had crept into my room this morning. My child complained about feeling uncomfortable after playing outside," said a Tianjin resident surnamed Liu.

Traffic authorities have advised drivers to reduce their speed and to use their fog lights.

According to Lu Huanzhen with Tianjin meteorological station, the sandstorm in Tianjin is expected to be over by Friday night.

Sandstorms were also reported in north China's Hebei Province and are expected to clear from Friday thanks to wind expected Saturday.

Parts of Beijing, as well as Gansu, Heilongjiang, Jilin, Shaanxi and Shanxi provinces and the autonomous regions of Inner Mongolia, Ningxia and Xinjiang will also see sandstorms from Thursday to Friday, said the National Meteorological Center.

Zhu Jiang, head of the Institute of Atmospheric Physics of the Chinese Academy of Sciences, said the sandstorms had traveled from Mongolia.

Ejin Banner of Alxa League saw the first sandstorm on Wednesday, with visibility reduced to less than 100 meters.

Strong wind reduced temperatures in the region by about four degrees Celsius. Local weather stations warned residents to keep their doors and windows closed, to buttress sheds and billboards, avoid riding bicycles and to remain alert for forest fires.

China has a four-tier color-coded system for severe weather, with red being the most serious, followed by orange, yellow and blue. Endi