 Tropical Storm Karina originated from the southern portion of the tropical wave — a tropical wave is an elongated low pressure area embedded within the easterly trade winds — that also spawned Hurricane Gustav in the Caribbean Sea . The wave crossed Central America and entered the eastern Pacific basin on August 28 . After two days , the wave spawned an area of low pressure south of Manzanillo , Mexico . The low was located beneath an area of moderate convection , but was nearing cooler waters and a moist , yet stable , air mass . By later that night , a low @-@ level circulation developed partially underneath deep thunderstorm activity . In an area favorable for development , a tropical cyclone formation alert was issued on September 2 . However , strong easterly shear separated the showers and thunderstorms from the center of circulation . Despite the shear , sufficient convection developed around the center ; the National Hurricane Center ( NHC ) classified it a tropical depression at 0600 UTC , while centered about 390 miles ( 630 km ) south of the southern tip of Baja California . The NHC initially did not recognize the system as a tropical depression and did not initiate advisories on it until several hours later . The depression quickly intensified into a tropical storm due to a brief relaxation of the wind shear and was given the name Karina while located about 25 mi ( 40 km ) north of Socorro Island . 
