JEDDAH: The drop in temperatures that accompanied the first day of examinations for first-year intermediate and secondary school pupils Saturday is expected to be followed by a period of unstable weather across the Kingdom lasting until Thursday. The Presidency of Meteorology and Environment (PME) said in its forecast for the 24 hours beginning Sunday morning that low to medium cloud forms could be expected over parts of the west and southwest of the Kingdom, extending to the southern parts of the center and east of the country. The clouds, the PME said, would be interspersed with cumulonimbus bringing thunder and rain over high ground in the west and southwest, citing the regions of Jizan, Asir, Al-Baha, and Najran. Those conditions could, it said, extend to Taif. The forecast added that the interior of the west and southwest of the Kingdom could expect surface winds to stir up dust and sand and reduce visibility, while the late night and early morning would see a strong chance of fog in high areas in the west and southwest. Temperatures, the PME said, would rise gradually in most regions of the country. With a weekly prognosis forecasting unstable weather until Thursday, the Civil Defense in Jeddah told local press that schools would be closed “if necessary” and that warnings issued over the last few days have shown that they have been able to preempt weather conditions in sufficient time. Civil Defense chief Abdullah Al-Jiddawi said that all warnings of adverse weather conditions are taken seriously in order to put into action pre-prepared plans to counter them, and that action on the ground is taken upon the announcement of PME warnings, which, he said, arrive six hours before the weather hits.