The Met Office predicted that a shallow westerly wave is likely to approach the upper parts of the country from 16th January and may persist until 19th January. It is also likely to strengthen from 20th January and grip most parts of the country from 21st January.
Under the influence of this weather system:
Rain-wind/thunderstorm with light to moderate snowfalls is expected in Gilgit-Baltistan (Diamir, Astore, Ghizer, Skardu, Hunza, Gilgit, Guanche, Shigar), Kashmir (Neelum valley, Muzaffarabad, Poonch, Hattian, Bagh, Haveli), parts of upper Khyber Pakhtunkhwa (Chitral, Dir, Swat, Kalam, Shangla, Kohistan, Battagram, Mansehra, Abbottabad, Haripur, and Bunner) from 16th (evening/night) to 19th January, with occasional gaps. While light rain/ snow is also expected in Murree, Galliyat, and surroundings from 18th to 20th January.
Widespread rain-wind/thunderstorm is expected in Gilgit Baltistan, Kashmir, Murree, Galliyat, Islamabad, Potohar region, in districts of Sargodha, Gujranwala, Lahore, Sahiwal, Multan, Faisalabad, Dera Ghazi Khan and Bahawalpur divisions and districts of Peshawar, Hazara, Malakand, Mardan, Kohat, Bannu, and Dera Ismail Khan divisions from 20th to 23rd January with occasional gaps.
Heavy snowfall is expected in Chitral, Dir, Swat, Kalam, Shangla, Kohistan, Battagram, Mansehra, Abbottabad, Murree, Galliyat, Neelum Valley, Bagh, Haveli, Rawalakot from 20th (night) to 23rd January with occasional gaps.
Rain-wind/thunderstorm is expected in Balochistan (Quetta, Ziarat, Chaman, Pishin, Qilla Abdullah, Qilla Saifullah, Noushki, Harnai, Zhob, Kalat, Barkhan, Sibi, Loralai, Musakhel, Turbat, Gawadar, Jiwani, Lasbella, Kech, Awaran, Chaghi, Panjgur, Khuzdar, Washuk, and Kharan) on 21st and 22nd January and Sindh (Karachi, Hyderabad, Dadu, Jacobabad, Naushero Feroz, Kashmore, Larkana, Shaheed Benazirabad, Mirpurkhas, and Ghotki) on 22nd & 23rd January with occasional gaps.
Moderate to heavy snowfall in (Quetta, Ziarat, Chaman, Pishin, Qilla Abdullah, Qilla Saifullah, Noushki, Harnai, Zhob) during the period.