A newly-formed tropical depression is expected to bring flooding rainfall to portions Indochina through at least the middle of the week.
Tropical Depression 19W developed to the east of Vietnam early Sunday night, local time. A little strengthening is expected through Monday and 19W could become a tropical storm shortly before landfall. Monday night the system will move into Vietnam and southern Laos, rapidly dissipated. However, the threat for flooding rain will continue.
Despite containing locally damaging winds at the time of landfall, flooding rain is expected to be the primary concern and will threaten areas for several days.
Numerous and drenching downpours are expected to cross Vietnam, Laos, Cambodia and southern Thailand through the first half of the week bringing the threat for isolated flooding. A few areas will be favored for more widespread and heavier rainfall.
One of these areas will be east-central Vietnam and southern Laos where heavy and widespread rain is expected on Monday and on Tuesday. Many areas will see near 150 mm (6 inches) of rain with more isolated areas receiving 300 mm (12 inches) of rain. Da Nang and the mountains to the north and west will be at the highest risk.
Due to the mountainous terrain of the region, rivers are expected to rapidly rise leading to life threatening flash flooding. Water-logged hillsides may give way leading to mudslides.
Another area that will be favored for more widespread, heavy rainfall will be in western Vietnam and Cambodia during the middle of the week. Widespread rainfall could reach 75-150 mm (3-6 inches) across this area over the course of a few days leading to the threat of flooding.
Drenching downpours and the threat for flooding could remain across Cambodia, Thailand and southern Myanmar during the second half of the week.