The Center reported that sudden rains, deep cloud and cold air have covered the northern region because of an influence of low pressure zone from high east- northward latitudes of Thailand accompanied with low pressure trough with over 5000 meters above sea level.
Currently, a cold air mass causing temperature in Hanoi starts to drop 20- 22 degrees Celsius, 11- 14 degrees Celsius in Lao Cai and 18- 19 degrees Celsius in Lang Son.
The weather center warned that the northern region will continue suffering small- medium rains while the provinces from Thanh Hoa to Quang Binh will experience medium- heavy rains.
Both Central Highlands and southern region have been influenced by powerful operation of the southwest monsoon.
From May 18- 19, the southern region has continued to experience medium- heavy rains, cyclone and strong wind.
