 On October 8 , a weak area of low pressure developed within a monsoon trough over the extreme eastern edge of the Pacific basin . Environmental conditions ahead of the system were forecast to become gradually favorable for tropical cyclogenesis . Situated near Costa Rica , scattered convection accompanied the well @-@ defined system . This low became less defined over the following days while remaining in the same general area . The National Hurricane Center ( NHC ) began monitoring the system for long @-@ term cyclogenesis on October 13 , at which time the low was situated 150 mi ( 240 km ) south of Guatemala . Organization was prolonged and slow ; however , the convergence of a Kelvin wave and a Gulf of Tehuantepec gap wind event on October 15 spurred a significant increase in convection . 
