The Meteorological Forecasting Division under the Department of Hydrology and Meteorology has issued a ‘heavy to very heavy’ rainfall warning for Tuesday and Wednesday.

Issuing a ‘monsoon special bulletin’ on Monday morning, the Met Office said that the monsoon trough is positioned north of the average place in the east and south of the average place in the west, and this unusual positioning could lead to more intense rain. The monsoon trough is a low-pressure area that brings moisture-laden winds from the oceans and causes increased cloudiness and rains.

“There is a chance of heavy to very heavy rainfall in some places of Koshi, Bagmati, Gandaki, Lumbini, and Sudurpaschim provinces and a few places of Karnali and Madhesh provinces,” reads the bulletin issued by the Met Office. “There is also a chance of extremely heavy rainfall in one or two places of Bagmati, Gandaki, and Lumbini provinces.”

The Met Office warned of the risk of landslides, debris flow, and land erosion in the hills and risks of floods and inundation in urban areas and in the Tarai. Water levels in small and big rivers could rise, and daily life, agriculture, health, tourism, and land and air transportation could also be affected, according to the bulletin. The Met Office has asked the general public and all relevant agencies for precautions.

This is the sixth special bulletin issued by the Met Office since the start of the monsoon on June 10.

The monsoon season in Nepal generally begins on June 13 and ends on September 23. This year, the monsoon entered Nepal from the southwest on June 10, three days ahead of the usual onset date. Last year, it started on June 14, a day later than normal.

This year, the division has forecast above-normal rains and above-average maximum and minimum temperatures this monsoon, which could unleash extreme weather events such as flooding, inundation, and landslides.

Several districts have already reported incidents of landslides, flooding and lightning since the start of the monsoon season.

According to the National Disaster Risk Reduction and Management Authority, at least 150 people have died, and scores have been injured and missing in landslides, flood and lightning-related incidents since June 10.

What do red, orange and yellow warnings signify?

Red warning: According to Met officials, a red warning means looming extreme weather conditions. Excessive rainfall, floods, landslides, inundation, and others are likely to cause widespread damage. For the general public, it is a message to keep themselves and others safe from the extreme weather consequences and not to travel in risky zones.

“Along with the general public, this is also an alert to all agencies concerned to gear up for response,” said Raju Pradhananga, a senior meteorologist.

Red alerts have been issued for the districts of Taplejung, Panchthar, Sankhuwasabha, and Terhathum in the Koshi province; and Rasuwa, Chitwan, Nuwakot, Dhading, Sindhupalchok, and Dolakha in the Bagmati province. Likewise, Myagdi, Kaski, Baglung, Parbat, Syangja, Tanahun, Nawalparasi-East, Lamjung and Gorkha districts of the Gandaki province are also in the red zone.

Similarly, red alerts have been issued for Kapilvastu, Rupandehi, Palpa, Gulmi, Nawalparasi-West, Dang, Banke, Bardia, Gulmi, Arghakhanchi of Lumbini province, as well as Kailali, Kanchanpur, Dadeldhura, Doti and Baitadi of the Sudurpaschim province.

Orange warning: An orange warning also means moderate risks. Experts say severe situations due to extreme weather events are very likely in the said districts. For the general public, it is a message to make preparatory plans for potential emergencies. As the probability of extreme weather events is high, it is also a request not to travel in risky zones—landslide-prone roads and riverbanks, among others. According to Pradhananga, it is also a request to people to protect themselves and family members.

The orange warning has been issued for the Okhaldhunga, Jhapa and Morang districts of the Koshi province; Siraha, Saptari and Dhanusha of Madhesh, and Ramechhap, Kathmandu and Bhaktapur of Bagmati. Orange warning has been also issued in Manang of the Gandaki province; Rukum-East and Rolpa of Lumbini, Dailekh, Surkhet, Salyan, Rukum-West, Jajarkot and Kalikot of the Karnali province; and Darchula and Achham of the Sudurpaschim province.

Yellow warning: A yellow warning signifies serious consequences from extreme weather events, but its chances are very low. The bad weather conditions could disrupt daily lives. The yellow warning has been issued in Mustang, Dolpa, Mugu, Humla, Jumla, Bajura and Bajhang districts.