Double deluge: Tropical Storm Manuel and Hurricane Ingrid hit Mexico at the same time

Tropical Storm Manuel is drenching Mexico's southwest Pacific coast as Hurricane Ingrid barrels towards the country’s east coast. Ingrid, the second hurricane of the Atlantic storm season, was expected to reach mainland Mexico early Monday.

At least 21 people in four states have died in building collapses and landslides caused by torrential rain, Luis Felipe Puente, national coordinator for Mexico's emergency services, told a press conference Sunday.

Manuel has maximum sustained winds of 70 miles per hour, and Ingrid has top sustained winds of 85 miles per hour.

Michael Schlacter, founder of Weather 2000 Inc. in New York, told Bloomberg News that the main impact of the two storms will be “mammoth rainfall amounts” across southern Mexico, which could be soaked by rain for five days. “The worst thing for heavy rain are hills, mountains and mud. The consequences for humanitarian purposes are just that more horrific.”

Some 10 to 15 inches of rain is expected over parts of the Mexican states of Oaxaca and Guerrero due to Manuel. Forecasters predict Ingrid will dump 15 inches of rain over much of eastern Mexico.

A hurricane warning is in effect for Cabo Rojo to La Pesca, the US National Hurricane Center in Miami said in a statement. “Hurricane conditions are expected in the hurricane warning area early Monday, with tropical storm conditions expected by late Sunday,” the hurricane center said.

Manuel has already damaged more than 20 highways, 12 bridges and 1,000 homes in the Gulf state of Veracruz, the state's civil protection authority said. 

Officials in Veracruz started evacuating coastal residents on Friday, moving more than 5,300 people out of their homes. Officials have also canceled Independence Day celebrations scheduled for Sept. 15 and 16 in the cities of Tampico, Madero and Altamira in Tamaulipas state, where Ingrid is expected to make landfall.