PORT-AU-PRINCE: Authorities in Haiti canceled all local flights Monday as severe weather bears down on the impoverished Caribbean nation. Heavy rains and high winds are threatening the area as the twentieth tropical wave of the season moves through the region, causing conditions the US National Hurricane Center said have a strong chance of turning into a tropical storm within hours. Haiti shares the mountainous island of Hispaniola with the Dominican Republic to the east. Severe weather poses a particular threat to Haiti — the poorest country in the Americas — increasing the risk of landslides and floods in a country that struggles with erosion and poor infrastructure. Haiti has been crippled by long-term political instability and a devastating quake in 2010. Hurricane season began June 1 and runs through November 30.