Natal's City Hall declared the alert late yesterday, following two days of near-continuous rains that reached the area's average for the entire month of June. More rains are expected throughout today.
The US-Ghana match is scheduled for tomorrow afternoon.
The statement from Natal's City Hall says no deaths or injuries have been reported in the flooding, but residents of two buildings were evacuated as a precaution. Local news reports showed images of a huge crater in a residential street.
The southern Brazilian regions of Parana and Mato Grosso do Sul have also been hit by recent flooding.