California Braces for Double Whammy of ‘Pineapple Express’ Storms
Residents across California are preparing for the arrival of two powerful atmospheric river storms, commonly referred to as a “Pineapple Express,” set to bring heavy rain and upper-elevation mountain snow over the next week.
Understanding the Pineapple Express Phenomenon
The National Oceanic and Atmospheric Administration describes atmospheric rivers as narrow atmospheric regions responsible for transporting moisture from the tropics to northern latitudes. When these moisture bands originate in the tropical Pacific near Hawaii and target the U.S. West Coast, they form what is known as a Pineapple Express.
Breathtaking satellite imagery of a stunning mid-latitude cyclone off the West Coast that will steer a significant atmospheric river into California tomorrow. pic.twitter.com/3hl49Wnq12
— Colin McCarthy (@US_Stormwatch) January 30, 2024
Week-Long Onslaught of Storms
Starting Wednesday and lasting a week, California will face the impact of two Pineapple Express storms, unleashing significant rainfall and strong winds. UCLA climate scientist Daniel Swain emphasized the classic and robust nature of these atmospheric rivers during a recent webcast.
Timing and Characteristics of the Storms
Both storms are expected to affect major population centers in the state. The initial storm, arriving in Northern California on Wednesday, may bring 2 to 4 inches of rain and winds exceeding 30 mph. While not catastrophic, Swain warned of potential urban and small stream flooding in the region.
The second storm, anticipated to hit on Sunday, is expected to bring colder air and more substantial snowfall to higher mountain elevations. Southern California is likely to experience heavy rainfall and powerful winds, reaching up to 70 mph in the northern part of the state.
An impactful storm system will bring rain and wind to the area today and tonight. Minor flooding of streams and roadways is expected along with the potential for downed trees and power outages. Stay safe and use caution during your commute today. #cawx pic.twitter.com/JA6f1roNE2
— NWS Bay Area 🌉 (@NWSBayArea) January 31, 2024
Potential for Flooding Concerns
Swain highlighted the flood risk associated with both storms. The first storm could lead to urban and small stream flooding in Northern California, given the rapid precipitation. The second storm poses a greater threat to Southern California, with a potentially record-breaking low-pressure system intensifying on Sunday, exacerbating the risk of flooding in already saturated areas.
Wind is among the bigger concerns with today’s weather system. Strong and gusty southerly winds will develop through the day and into tonight. Given saturated soils downed trees and resulting power outages are likely. Stay safe out there! #cawx pic.twitter.com/iSddECletx
— NWS Bay Area 🌉 (@NWSBayArea) January 31, 2024
Computer models suggest that the Los Angeles region might receive over 7 inches of rain, while some northern areas could see even higher amounts. The bulk of the rainfall is expected in Southern California from Sunday through Wednesday. The state braces for the dual impact of these formidable Pineapple Express storms.
An atmospheric river will begin to impact the Western U.S. tonight and produce widespread low elevation rain, heavy mountain snow, and gusty winds.
Follow your local office by visiting https://t.co/GWrG0hTRHN pic.twitter.com/ncBxXhV7Cn
— National Weather Service (@NWS) January 30, 2024