The moderate high-pressure system from China will extend to cover Vietnam and the South China Sea leading to the confluence of southeasterly and southwesterly winds prevail over the upper country where hot weather occurs while during 28 April - 1 May, the westerly trough from Myanmar will move pass the North and the upper Northeast and the upper of Central. Outbreaks of summer storms are possible following with thunderstorms, gusty wind, hail and isolated heavy rains including lightning strike in some areas.