UNITED NATIONS, June 20 (Xinhua) -- UN humanitarians said on Thursday they are preparing to support the people of Central America and Mexico suffering from extreme wet weather that already has claimed 20 lives.

"Rainfall of up to 75 cm is expected by the end of the week, according to forecasts," said the UN Office for the Coordination of Humanitarian Affairs (OCHA). "This is due to a broad area of low pressure currently centered over northern Central America and southern Mexico, in a pattern known as a Central American Gyre."

OCHA said it is in close contact with the respective governments and stands ready to provide further guidance and support. Flooding and landslides hit the area from Saturday to Monday and, according to official reports, at least 20 people died in the affected countries.

The humanitarians said the countries and areas most impacted by the heavy rainfall are El Salvador, Guatemala, northwest Nicaragua, southwest Honduras and the Mexican states of Chiapas and Oaxaca.

"The first tropical storm of the Atlantic Hurricane season, known as Alberto, formed yesterday (Wednesday) in the Gulf of Mexico," OCHA said. "The storm made landfall in the Mexican state of Tamaulipas today (Thursday) and is expected to bring heavy rain and coastal flooding to northeastern Mexico and southern Texas in the United States later this week."

OCHA said the Atlantic hurricane season is expected to be more active than usual this year due to several factors, including near-record warm ocean temperatures in the Atlantic Ocean and the development of La Nina conditions in the Pacific.

The humanitarians said UN teams in Mexico and in the three Northern Central America countries of El Salvador, Honduras and Guatemala are monitoring the situation closely.

"As the Atlantic Hurricane season begins, the 2024 Humanitarian Response Plans for the region require more funding," OCHA said.

The humanitarians said the appeal for El Salvador, seeking 87 million U.S. dollars, is just 13 percent funded, while the 125-million-dollar plan for Guatemala is 18 percent funded and the appeal for Honduras, seeking 203 million U.S. dollars, is only 21 percent funded. ■