The General Authority of Meteorology and Environmental Protection has warned of inclement and unstable weather in most parts of the Kingdom from Friday until Monday. Several regions are expected to witness heavy rain accompanied by thunderstorms while some other regions will experience moderate rain and sandstorms with a speed of 55 km per hour and poor visibility. According to the authority, moderate rain accompanied by thunder and sandstorms with a speed of 55 km per hour will be experienced in Tabuk, Northern Border Region, Al-Jouf, Hail, Madinah, parts of Makkah region and highlands of Asir, Al-Baha and Najran. Inclement weather conditions will also be experienced in Al-Qassim, Riyadh and the Eastern Province. Moderate to heavy rain will hit north of Madinah region, and regions lying between Hail, Rafha, Wadi Dawasir and Dawadmi, the Saudi Press Agency reported.