Heavy rain will inundate coastal Oregon and northern California late this week into early next week, threatening serious flash flooding, mudslides and travel delays and cancellations.
A Pineapple Express will help to fuel the heavy rain as a storm plows into the Pacific coast Thursday into Saturday. The heaviest rain will soak Northern California during the day on Friday.
“A Pineapple Express is a continuous surge of tropical moisture extending from near Hawaii all the way into a West Coast storm,” AccuWeather.com Senior Meteorologist Bernie Rayno said.
This pattern can significantly enhance rainfall and threats such as flooding. Recent burn scar areas in California will be especially vulnerable to flooding and debris flows, since rain water cannot penetrate scorched ground.
Widespread rainfall amounts of 2-3 inches are expected in western Oregon and northern California, including in the Bay Area. In far northern California, amounts may exceed 5 inches from Thursday through Saturday.
Lengthy flight delays and cancellations are possible at San Francisco International Airport on Friday due to low clouds and excessive rainfall associated with the storm.
http://www.accuweather.com/en/weather-news/northern-california-rain-flooding-pineapple-express/41726723