The Met Office said the weather system is expected to strengthen from January 20 and is likely to grip most parts of the country from January 21.

Under the influence of this system, rain accompanied by wind and thunderstorms, along with light to moderate snowfall, is expected in Gilgit-Baltistan including Diamir, Astore, Ghizer, Skardu, Hunza, Gilgit, Ghanche and Shigar, as well as in Kashmir including Neelum Valley, Muzaffarabad, Poonch, Hattian, Bagh and Haveli. Parts of upper Khyber Pakhtunkhwa including Chitral, Dir, Swat, Kalam, Shangla, Kohistan, Battagram, Mansehra, Abbottabad, Haripur and Buner are also likely to be affected from the evening or night of January 16 to January 19, with occasional gaps.

The department added that light rain or snowfall is also expected in Murree, Galliyat and surrounding areas from January 18 to January 20.

Widespread rain with wind and thunderstorms is expected in Gilgit-Baltistan, Kashmir, Murree, Galliyat, Islamabad and the Potohar region, as well as in districts of the Sargodha, Gujranwala, Lahore, Sahiwal, Multan, Faisalabad, Dera Ghazi Khan and Bahawalpur divisions. Districts of the Peshawar, Hazara, Malakand, Mardan, Kohat, Bannu and Dera Ismail Khan divisions are also likely to receive rain from January 20 to January 23, with occasional breaks.

Heavy snowfall is expected in Chitral, Dir, Swat, Kalam, Shangla, Kohistan, Battagram, Mansehra, Abbottabad, Murree, Galliyat, Neelum Valley, Bagh, Haveli and Rawalakot from the night of January 20 to January 23.

Rain with wind and thunderstorms is also forecast in Balochistan including Quetta, Ziarat, Chaman, Pishin, Qilla Abdullah, Qilla Saifullah, Noshki, Harnai, Zhob, Kalat, Barkhan, Sibi, Loralai, Musakhel, Turbat, Gwadar, Jiwani, Lasbela, Kech, Awaran, Chaghi, Panjgur, Khuzdar, Washuk and Kharan on January 21 and 22.

Sindh districts including Karachi, Hyderabad, Dadu, Jacobabad, Naushero Feroz, Kashmore, Larkana, Shaheed Benazirabad, Mirpurkhas and Ghotki are expected to receive rain on January 22 and 23.

The Met Office warned that moderate to heavy snowfall is also likely in parts of Balochistan including Quetta, Ziarat, Chaman, Pishin, Qilla Abdullah, Qilla Saifullah, Noshki, Harnai and Zhob during the period.