According to Wikipedia, "a Pineapple Express is driven by a strong, southern branch of the Polar jetstream and is usually 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." Go figure. I only found this to be cool because it has been raining non-stop here the last couple days and the name of the cause is very closely associated with my blog. I am pretty sure, in fact, that someone came up with the name only after reading my blog. They saw my post yesterday, saw the name Pineapple Project, and invented "Pineapple Express." See, who said blogging was a waste of time? I am changing names of weather patterns. Maybe one day I'll even get my own hurricane!
Okay, not really. It seems the Pineapple Express has been a thing since the 50s. In 2006, The Puget Sound region from Olympia, Washington to Vancouver, BC received several inches of rain per day in November 2006 from a series of successive Pineapple Express storms that caused massive flooding in all major regional rivers and mudslides which closed the mountain passes. During the second week of January, 1952, a series of "Hawaiian" storms swept into Northern California, causing widespread flooding around the Bay Area.