Thunderstorms and heavy rainfall are forecasted to occur starting from 29 January 2026, 03:00 WIB in parts of Sumatera Utara especially in: Andam Dewi, Badiri, Hilimegai, Kolang, Lumut, Mazo, Muara Batang Gadis, Muara Batang Toru, O'O'U, Pandan, Pinangsori, Sarudik, Sibabangun, Sibolga Kota, Sibolga Selatan, Sibolga Utara, Sirandorung, Sorkam, Sorkam Barat, Sosor Gadong, Suka Bangun, Susua, Tapian Nauli, Tukka, Ulunoyo, Ulususua. These conditions may lead to reduced visibility, strong winds, and localized flooding. The public is strongly advised to remain vigilant during this period, limit outdoor activities, and take all necessary precautions to ensure safety. Conditions are expected to gradually improve by 29 January 2026, 06:12 WIB.