RIYADH: Saudi authorities on Friday issued weather safety warnings to the public after huge sandstorms forced many residents in Riyadh and elsewhere in the Kingdom to stay indoors. Winds of up to 47 km per hour hit the Saudi capital causing widespread traffic disruption due to low visibility. And sandstorms caused similar problems in the Qassim and Eastern Province regions. The General Authority for Meteorology and Environmental Protection forecasted the dusty conditions to hit Najran, eastern parts of the southwestern highlands, and the southern end of the western Red Sea coast. Thunderstorms were predicted on the heights of Jazan, Asir, Baha and Makkah region, extending to the southern parts of the heights of Madinah. In Riyadh, the sandstorm started on Thursday night, limiting visibility in the capital. Riyadh traffic officials advised motorists to take extra care and drive slowly, and the General Directorate of Civil Defense urged residents to avoid picnicking on sands over the weekend and to stay indoors wherever possible. Health experts warned that exposure to sandstorms caused breathing difficulties, especially for people with respiratory problems. The maximum temperature recorded during the sandstorm was 44 degrees Celsius with a low of 29 degrees Celsius. Humidity was pegged at 9 percent.