Historic rain event in Pac NW

An incredible “Pineapple Express” is dumping torrential rains across a large swath of western Washington and Oregon. 4-9 inches have fallen in the lowlands already, and up to 15 inches have fallen in the orographically favored areas in the Cascades. Rain is ongoing, and is expected to intensify even further overnight as a powerful wave acts on the nearly 2 inch precipitable water plume to create almost inconceivable rainfall rates on SW facing slopes. Rates of 1-3 inches/hour are possible, and they may be maintained for several hours. Even where this “super deluge” isn’t occurring, rainfall on the order of .5-1 in/hr is almost certain. Thus, would expect an additional 4-8 inches in the lowalnds by tomorrow afternoon, and possibly as much as 12 more inches in the mountains (and the bulk of that will fall in the next 8-12 hours). Needless to say, serious and life-threatening floods are currently occuring and will get much worse as the night progresses. New floods of record will likely be established on many rivers, some by as much as 10 feet above the previous all-time high water mark!!! There are a number of urban areas and levees that are currently threatened by a flood of this magnitude, so major damage is a possibility. Stay tuned. The weather in CA will be increasingly rainy over the next week, but nothing like the amazing rain event currently unfolding in Washington. More on that later.

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