General weather patterns:
From 28 Jan to 03 Feb 2020, there was no rainfall in the LMB. Based on the weather outlook bulletins and maps issued by the Thailand Meteorology Department (TMD) were used to verify the weather condition in the LMB. They stated that for the next 3 months from Jan to Mar 2020, the cold appears because the influentially high-pressure air mass areas prevail over Thailand for the whole month. However, at some periods, coldly high-pressure air masses from China will meet hot air masses already prevailing over LMB. They also stated that the cool weather throughout the week is covered at mountainous areas and mountain tops. Figures 1 presented the weather map for 30 Jan and 03 Feb 2020.
General behavior of the Mekong River:
This week from 28 Jan to 03 Feb 2020, water levels from Chiang Sean were slightly increased, varied from 0.02 m to 0.09 m since finishing the test of equipment of hydropower station at Jinghong, China at 4 Jan 2020. Water levels at this station were fluctuated above its Long-Term -Average (LTA). However, water level at Luang Prabang and Chiang Khan are likely impacted by hydropower dam at Xayaburi and upstream hydropower dams in which water level at this station were raised up close to it Maximum levels and varied from 0.04 m to 0.08 m. Water levels at Chaining (downstream of Xayaburi) were stay below their LTAs. And water levels at stations in the middle part of LMB from Vientiane to Pakse were slightly increased based on the trend inflows from upstream, but their water levels are still staying below their LTAs and even belpw to their Minimum levels (Nong Khai). The station at Nong Khai is considered critical condition). Follow the same trend of water levels from upstream, stations at Stung Treng, Kratie, Chaktomuk on the Bassac, Phnom Penh Port and Neak Luong were very low and stay closely to their minimum levels (these stations were considered critical condition). For the 2 tidal stations at Tan Chau and Chau Doc, water levels decreased followed the same trends as minimum levels in January 2020. The actual water levels at most of the key station are staying below their LTAs and even Min Levels (see its hydrograph in Annex B).
Source: Mekong River Commission