La Nina, “Little Girl” is characterized by unusually cold sea surface temperature is the equatorial Pacific. The typical weather pattern of the Pineapple Express is as follows: … A moisture plume extends northeastward from the western tropical Pacific towards the Hawaiian Islands.
Pineapple Express is a non-technical term for a meteorological phenomenon characterized by a strong and persistent flow of atmospheric moisture and associated with heavy precipitation from the waters adjacent to the Hawaiian Islands and extending to any location along the Pacific coast of North America. A Pineapple Express is an example of an atmospheric river, which is a more general term for such narrow corridors of enhanced water vapor transport at mid-latitudes around the world.
A Pineapple Express is driven by a strong, southern branch of the polar jet stream and is marked by the presence of a surface frontal boundary which is typically either slow or stationary, with waves of low pressure traveling along its axis. Each of these low-pressure systems brings enhanced rainfall.
The conditions are often created by the Madden–Julian oscillation, an equatorial rainfall pattern which feeds its moisture into this pattern. They are also present during an El Niño episode.