General weather patterns:
From 26 May to 01 June 2020, there were some rainfall in the LMB. The weather outlook bulletins (3 months weather forecast: May-Jun-Jul) and maps issued by the Thailand Meteorology Department (TMD) were used to verify the weather condition in the LMB. They stated that from May-Jun-Jul 2020, the low-pressures of air mass cells are developed around the Mekong Region that cause some depressions and tropical cyclones, resulting summer thunderstorms and rain in this period. Moreover, coldly high-pressure air masses from China will meet hot air masses already prevailing over LMB, resulting in abnormal rainfall in the first week of June 2020. Figure 1 presented the weather map on 31 May 2020.
Although the Dry Season 2020 is finished, but still the scattered hotspots were detected in Cambodia and Thailand, and isolated ones were also detected in Myanmar, Lao PDR and southern Viet Nam in early June 2020.
According to the Asian Specialized Meteorological Centre (ASMC), the predicted below normal rainfall in the Mekong region is showed in June 2020. For the season June to August 2020, there is an increased chance of above-normal rainfall for most parts of the equatorial region. Figure 2 showed the predicted 3 months rainfall in Jun-Jul-Aug 2020 in Southeast Asia.
Source: Mekong River Commission