Tropical storm Nate killed 22 people in Central America on Thursday, and is headed towards the United States Gulf Coast, Reuters reported. The storm could strike the US coast and Mexico’s Caribbean as a hurricane this weekend.

At least 11 people were killed in Nicaragua, seven were missing and thousands had to evacuate their homes because of flooding, the country’s president Rosario Murillo said. “Sometimes we think we think we can cross a river and the hardest thing to understand is that we must wait,” Murillo said on state radio, warning people to avoid dangerous waters.

In Costa Rica, at least eight people were killed, including two children. 17 people were reported missing, while 7,000 had to take refuge in shelters from the rain and floods. The country has declared a state of emergency. Two youths drowned in a river in Honduras. A man died in a mudslide in El Salvador, while another was reported missing, emergency service personnel in the country said.

Nate is expected to strengthen to a Category 1 hurricane by the time it hits the US Gulf Coast on Sunday.