Pineapple Express Threatening the West With Heavy Rain and Snow
Alexis Thornton
2 months ago
A classic Pineapple Express is gearing up to bring rain and snow to much of the West Coast beginning on Friday and lingering into early next week. The system is setting up to be the most impactful rainstorm of the year for the West, ushering in the threat of flooding, landslides, and dangerous road conditions. Here is a more detailed look at what you can expect in the western U.S. in the days ahead.
Pineapple Express Targets West Coast
It is going to be a messy weekend for much of the western U.S. thanks to a Pineapple Express event that will produce an atmospheric river of moisture. A mix of rain and snow will fall across the region depending on temperatures and elevation.
The atmospheric river is forecast to douse the West Coast beginning Friday and lasting for several days. An atmospheric river is defined as a plume of tropical moisture that travels a far distance and unleashes on one specific area. These plumes most often get their start in the central Pacific near the Hawaiian islands, hence the nickname of the Pineapple Express.
The upcoming Pineapple Express event is forecast to aim for the Pacific Northwest and Northern California. This is generally the wettest time of the year for the Northwest and California, however, it has been particularly dry thus far this January.
For example, San Franciso has only recorded 0.13 of an inch of rain dating back to the beginning of the year. This compares to the historical average for January of nearly 4 inches. Likewise, Redding, California has only seen 0.63 of an inch of rain, only 10% of the average for January.
The risk of flooding will be amplified because it has been so dry throughout the Northwest and California. This is because overly parched ground has a more difficult time absorbing incoming moisture, instead repelling it and sending it flowing.
The threat of landslides will also be a concern due to the heavy rain. All of this will inevitably raise the chances of travel delays, both on the roads and in the air due to the anticipated gusty winds.