Heavy Monsoon Rain Raises Flood Risk Across Nepal

A more active monsoon is expected to bring rain across most of Nepal on Sunday, with extremely heavy rainfall possible in parts of four provinces. Weather and disaster management authorities have urged people to remain alert as the risk of flash floods, landslides, inundation, erosion and debris flows rises.

The warning covers both the hills and the plains. Small rivers may swell without much notice, slopes weakened by continuous rain could give way, and low-lying urban and Tarai settlements may face waterlogging. Travel along riverbanks, steep terrain and landslide-prone roads will require particular caution.

The Department of Hydrology and Meteorology said the monsoon trough in the western region has shifted slightly north of its average position and is now close to Nepal’s Tarai. In the east, the trough remains near its normal position.

The system has brought widespread cloud cover across the country.

Light to moderate rain is already being recorded at several places in Koshi, Bagmati, Gandaki and Lumbini provinces. One or two locations in Karnali Province have also received rainfall.

Heavy rain risk during the day

Most parts of the country will remain cloudy during the day.

Many places in the Himalayan region and most locations in the hills could receive light to moderate rain accompanied by thunder and lightning. Rain is also expected across many areas of the Tarai.

Snowfall may occur alongside rain in the high Himalayan region.

Several locations in the hills and Tarai of Koshi, Lumbini and Sudurpashchim provinces could receive heavy to very heavy rain.

Heavy rain is also possible at some places in Bagmati and Gandaki provinces, as well as at one or two locations in the Tarai areas of Madhesh, Bagmati and Gandaki provinces.

The most serious daytime warning applies to one or two locations in the hills and Tarai of Koshi, Gandaki, Lumbini and Sudurpashchim provinces, where rainfall could reach extremely heavy levels.

Such rainfall can become dangerous quickly. The concern is not limited to the amount of rain recorded in one place; water flowing down from surrounding slopes and catchment areas can raise river levels or flood settlements even where the rainfall appears less intense.

Little improvement expected overnight

Conditions are not expected to improve significantly at night, with most of the country remaining under dense cloud.

Moderate rain with thunder and lightning is forecast at some places in the Himalayan region. The possibility of snowfall will continue in the higher Himalayan areas.

Rain could occur at most places in the hill districts of Koshi and Sudurpashchim provinces.

Many locations in the hills of Bagmati, Gandaki, Lumbini and Karnali provinces are also likely to receive rain. Most parts of the Tarai could see light to moderate rainfall with thunder and lightning.

At night, heavy to very heavy rain is possible at several locations in the hills and Tarai of Koshi, Gandaki, Lumbini and Sudurpashchim provinces.

One or two places in the hill and Tarai regions of Madhesh and Bagmati provinces may also receive heavy rain.

The department has warned that some locations in Koshi and Sudurpashchim provinces face the possibility of extremely heavy rainfall overnight.

Authorities warn of sudden local disasters

Continuous and intense rain could cause the water level in small rivers and streams to rise suddenly. Landslides and debris flows may occur in the hills, while flooding and waterlogging could affect the Tarai and urban areas.

The National Disaster Risk Reduction and Management Authority has asked residents of vulnerable areas to stay alert to possible flash floods, landslides, inundation, erosion and debris flows.

People living near rivers and streams, on unstable slopes or close to known landslide zones have been advised to watch local conditions carefully.

Authorities have also urged travellers to take additional precautions on roads passing through steep terrain and areas with a history of landslides. Conditions may deteriorate rapidly where heavy rain continues for several hours, particularly during the night when blocked roads, rising water and slope failures can be harder to detect.