 On August 19, the convective structure began to show signs of organization as the associated atmospheric pressure lowered, and with a progressively favorable environment situated ahead of the wave its chances of undergoing tropical cyclogenesis markedly increased.The strong thunderstorm activity continued to become more pronounced around the main low-pressure feature.By August 20, the National Hurricane Center noted that tropical cyclone formation was imminent as the wave neared the Lesser Antilles, and a reconnaissance aircraft confirmed the presence of a small surface circulation center just southwest of a burst of vigorous convection and unusually high sustained winds, indicating sufficient organization for the cyclone to be upgraded into Tropical Storm Irene at 23