WASHINGTON — A powerful atmospheric river commonly referred to as a “Pineapple Express” is expected to impact western Washington and Vancouver Island from late this weekend into early next week, bringing a surge of warm, moisture-laden air from the subtropical Pacific near Hawaii. Forecast guidance shows a prolonged period of moderate to heavy rainfall, rapidly rising snow levels, and an increased risk of river flooding in vulnerable regions.
Meteorologists describe this system as a deep feed of subtropical moisture, a classic Pineapple Express setup that often delivers high rainfall totals over a short period of time across the Pacific Northwest.
What the Pineapple Express Means for the Pacific Northwest
The Pineapple Express is not a single storm but a long, narrow corridor of intense atmospheric moisture stretching thousands of miles across the Pacific Ocean. In this case, the moisture plume originates near Hawaii and is directed northeast into western Washington and southern British Columbia, including Vancouver Island.
Because the air mass is unusually warm for January, it carries significant moisture while also raising temperatures aloft — a key factor in increasing runoff and flood potential.
Heavy Rainfall Expected in Western Washington and Vancouver Island
Forecast data indicates a moderate to high-end rainfall event, especially along coastal areas, the Olympic Peninsula, and northwestern Washington. The most persistent rain is expected as the atmospheric river stalls over the region before gradually weakening early next week…