South Vietnam area is really in Lowest Air Pressure compared to surrounding areas. This tends to make South Vietnam having strong wind, and because winds from South East and North East still bring humidity, so South Vietnam tends to have very high level of rainfall, therefore worsening huge floods already happened at Mekong Delta area.
At attachment, T is center of small typhoon (NW of Luzon). This typhoon moving SW to South Vietnam. This typhoon intensifying because absorbing humidity from surroundings, so when it reach South Vietnam, the intensity forecasted to be higher.
At Chiang Mai, wind is blowing from H at India to L at Vietnam (from W-NW), with possibility of strong wind, but dry.
By Roosdiarto YG1CRR