The reason was due to an appearance of a low pressure trough being compressed by high pressure system from the north, causing heavy to heavy rain in the northern region.
In next couple days, the south- central and southern region will also suffer showery weather and thunderstorm because of strong operation of inter-tropical convergence zone.
Medium- heavy rains are warned to cover the southern region as well as the central highlands provinces of Dak Lac, Dak Nong and Lam Dong.