The MM5 model was tested to see how well it could predict rainy and dry seasons in South America. Different simulations were run with various settings to find the best combination for accurate predictions. While all simulations showed some success, they tended to underestimate rain in the La Plata Basin area due to a problem with moisture flow. Simulations that controlled the wind patterns did better than those that didn't. No single simulation was perfect for the whole region, but one using specific settings was best for different latitudes. Overall, combining results from multiple simulations gave the most accurate predictions.