The Pakistan Meteorological Department (PMD) said a monsoon low that formed over the northwest Bay of Bengal and adjoining Odisha coast had moved into South Chhattisgarh and nearby areas.
The weather system is expected to move westwards, bringing rain and thunderstorms to parts of Sindh, according to the Met Office.
Karachi is expected to receive light rain and thunderstorms from 14 to 16 September. Other areas of the province may experience dust storms, thunderstorms and rain.
The PMD has warned that some districts could receive moderate to isolated heavy rainfall, accompanied by strong winds and thunderstorms.
Tharparkar, Umerkot, Mirpurkhas, Badin, Thatta, Sujawal and Tando Muhammad Khan are expected to receive dust-thunderstorm rain, with some moderate to isolated heavy falls, from Sunday evening until 16 September.
Light to moderate dust-thunderstorm rain is also forecast in Sanghar, Khairpur, Hyderabad, Tando Allahyar, Matiari, Shaheed Benazirabad and Jamshoro between 14 and 16 September, with intermittent breaks.
The Karachi division may also experience thunderstorms and light rain during the same period.
Sindh Chief Minister's Adviser on Rehabilitation Giyanchand Essrani said several parts of the province were likely to receive rain from 13 to 16 September.
He directed deputy commissioners and relevant departments to keep machinery and staff ready to respond to any situation arising from the weather.
The Sindh Provincial Disaster Management Authority (PDMA) and Sindh Emergency Rescue Service 1122 have also been directed to remain on high alert throughout the period.
The PDMA asked deputy commissioners, District Disaster Management Authorities and other relevant officials to take necessary precautionary and mitigation measures.
Authorities were also urged to remain vigilant and take steps to minimise the risk of any untoward incident during the rain spell.
