Wednesday March 22, 2023
San Francisco Chronicle —
The low-pressure system that was sitting over the open waters of the Pacific Ocean on Monday night quickly intensified into a powerful storm that is forecast to reel in more heavy rainfall, strong winds and the risk for thunderstorms along most of the California coast through Tuesday.
The growth of this storm was forecast by weather models like the European, Canadian and American. But some uncertainties made this a challenging forecast as models struggled to pinpoint where the center of the storm would come ashore and just how strong it would become by Tuesday morning.
The challenges over where the storm would form became apparent by early Monday morning as the European and American models flipped between a landfall near the Bay Area or closer to Southern California. Through the use of statistical analysis and a blend of models, meteorologists pinned down the area where the storm would most likely come ashore: the Central Coast.
This southern trajectory generally lines up with a trend common in spring, as atmospheric rivers between Hawaii and California — often called a Pineapple Express — gradually lose their flow. And like a hose slowly being shut off, atmospheric rivers begin to flow more toward Southern California, leaving the Bay Area and Sacramento Valley with less moisture for storms.