Myanmar’s Department of Meteorology and Hydrology has warned that heavy rain is likely in some areas between July 21 and 29 as the southwest monsoon strengthens over the Andaman Sea and the Bay of Bengal, accompanied by atmospheric instability.

Frequent to widespread thundershowers are forecast for Nay Pyi Taw, Yangon, Bago, Ayeyarwady, Tanintharyi, Kachin, Kayah, Kayin, Chin, Mon, Rakhine and Shan states, as well as northern Sagaing Region, with isolated heavy rainfall expected in some locations.

The department also warned of strong winds, flash floods and landslides during periods of intense rain. Along Myanmar’s coast and offshore waters, occasional squalls with winds of up to 35 mph (56 km/h) and waves of 9 to 11 feet are expected. Residents in hilly and low-lying areas, as well as domestic airlines, fishing vessels and ships, have been urged to take precautions.

For the third 10-day period of July, the department said a low-pressure area could develop over the Bay of Bengal, while monsoon conditions are expected to remain moderate to strong.