Hurricane Matthew churns towards Haiti, Jamaica agenciesKINGSTONHurricane Matthew, the most powerful Caribbean storm in a decade, churned towards Haiti, Jamaica and Cuba Sunday on a path forecasters said could take it to the eastern United States. At 0600 GMT "powerful Matthew" was "moving slowly north-northwestward" from the Caribbean coast of Colombia and Venezuela at a speed of six miles (nine kilometers) per hour, the Miami-based National Hurricane Center said. Briefly a…