Due to the southwestern ridge edge of the high pressure in combination with upper-air wind convergence at 1500-5000 meters above surface, the Northern region is forecast to experience medium- heavy rainfall of above 100 mm along with risks of lightning, whirlwind, cyclone and hail in some places.
Additionally, newly- formed low- pressure trough passing through the South- Central region connecting with moderate- intensity operation of the southwest monsoon continues to cause tropical medium- torrential downpours, thunderstorm, lightning, hail and whirlwind in the Central Highlands and Southern regions from October 1.