Summary (tl;dr)

The remnants of Tropical Storm Rachel are trending as they bring unusual and significant impacts, including heavy rainfall, flash flooding, and coastal hazards, to Southern California, northern Baja California, and the U.S. Southwest, exacerbated by record-warm ocean temperatures.

Essential Background

Tropical storms typically weaken significantly over cooler Pacific waters before reaching the West Coast of the United States. However, recent El Niño conditions and a persistent marine heat wave have led to ocean temperatures 10 to 13 degrees Fahrenheit higher than normal off the coast of California. These "unprecedented" conditions created an environment conducive for Tropical Storm Rachel to maintain its strength closer to the coast than is typical for such systems.

The Full Story

"Remnants of Rachel" is trending as the former Tropical Storm Rachel, now a post-tropical cyclone, continues to bring significant weather impacts across Southern California, northern Baja California, and the broader U.S. Southwest. After making landfall in northern Baja California on Saturday night, October 10, 2026, the storm's moisture and associated weather systems have delivered periods of moderate to heavy rain, strong gusty winds, and dangerous coastal conditions. Flash flood warnings were issued for parts of San Diego, Riverside, and Imperial counties in California, including areas of the Coachella Valley, as well as cities like El Cajon, Santee, and Blythe. Coastal areas, including Orange and San Diego Counties, experienced significant coastal flooding and beach erosion due to elevated surf and high tides. While the storm's tropical characteristics are dissipating, its remnants are combining with an upper-level low-pressure system to produce ongoing heavy rainfall and strong winds, leading to what some are calling "weather whiplash" following a period of record-breaking heat.

Why It Matters

This event is significant because it is a rare occurrence for a tropical storm or its remnants to directly impact Southern California with such intensity, making it only the second tropical storm watch issued for San Diego County since Hurricane Hilary in 2023. The unusual strengthening and proximity of Rachel to the coast are directly linked to elevated ocean temperatures, underscoring the influence of ongoing climate patterns like El Niño and marine heat waves. The resulting heavy rainfall poses risks of flash flooding and mudslides, while high surf and coastal flooding threaten infrastructure and public safety along the coastline. The event highlights the increasing potential for extreme and unpredictable weather patterns in regions not typically accustomed to tropical storm impacts.

Geographic Location

• Northern Baja California, Mexico (landfall of Tropical Storm Rachel)
• San Diego County, California, United States (heavy rain, flash flooding, tropical storm watch, coastal flooding)
• Orange County, California, United States (coastal flooding, beach erosion)
• Los Angeles County, California, United States (record rainfall, general rainfall)
• Riverside County, California, United States (flash flood warning, heavy rain)
• Imperial County, California, United States (flash flood warning, street flooding)
• Coachella Valley, California, United States (flash flood warning, significant precipitation)
• Mojave Desert, California, United States (significant precipitation, strong wind gusts)
• Inland Empire, California, United States (significant precipitation)
• Arizona, United States (heavy rain, gusty winds)
• Nevada, United States (heavy rain, gusty winds, flood risks, potential snow in High Sierra)
• Great Basin, United States (potential for significant flash and urban flooding)