JEDDAH — The National Center for Meteorology (NCM) issued red alerts for heavy rain and possible flash floods across parts of Asir and Makkah on Monday, as moderate to heavy thunderstorms are forecast across several regions of Saudi Arabia. In Asir, the red alert covers Al-Harajah, Al-Farshah, Sarat Abidah and Dhahran Al-Janub from 12 p.m. to 9 p.m.Meanwhile, a red alert was issued for Rabigh, Madrakah and Huda Al-Sham in Makkah Region from 1 p.m. to 9 p.m. Both alerts warn of strong winds, near-zero horizontal visibility, hail, flash floods and thunderstorms. According to the NCM's Monday forecast, moderate to heavy thunderstorms capable of causing flash floods, accompanied by hail and active winds stirring up dust and sand, are expected over parts of Jazan, Asir, Al-Baha, Makkah, Madinah, Hail, Tabuk, Al-Jouf and the Northern Borders. Light to moderate rain is also forecast over southern parts of Riyadh and the Eastern Province, as well as parts of Najran. Fog may form during the night and early morning over coastal parts of Tabuk, Madinah, Makkah and the Eastern Province. For temperatures, Dammam is forecast to record the highest temperature at 41°C, followed by Makkah and Madinah at 40°C. Buraidah is expected to reach 38°C, followed by Riyadh and Jeddah at 37°C, and Tabuk, Hail and Jazan at 36°C.Sakaka is forecast to reach 33°C, Arar and Najran 32°C, Abha 26°C and Al-Baha 25°C. Humidity is forecast to reach 90 percent in Dammam, 85 percent in Jeddah, Abha, Al-Baha and Jazan, 80 percent in Makkah and Tabuk, and 75 percent in Arar and Sakaka. Humidity levels are expected to reach 65 percent in Hail and Najran, 60 percent in Madinah, 35 percent in Riyadh and 30 percent in Buraidah.