SOUTHERN CALIFORNIA, CA — Meteorologists are closely watching a developing tropical disturbance in the Pacific that could become an unusual threat to Southern California later this week.
The system is currently forming off the coast of Baja California, but weather prediction models indicate that it could become more organized as it moves through warmer ocean waters.
Meteorologists say there is a possibility that the disturbance could develop into a tropical depression within the coming days, followed by additional strengthening.
“This is the disturbance that, if it does form and come together, could make its way right into Southern California about one week from today,” meteorologists said.
The possibility is drawing attention because tropical systems capable of reaching California are relatively uncommon.
National Hurricane Center Sees High Development Chances
The National Hurricane Center is already assigning a high probability to tropical development in the area.
A National Weather Service meteorologist said the center was forecasting an 80% chance of a tropical depression forming within 48 hours, with that probability increasing to 90% over the next seven days.
A tropical depression develops when an organized system has sustained winds below tropical-storm strength. If winds increase enough, the system can be upgraded to a tropical storm.
Meteorologists explained that the key distinction between a tropical storm and a hurricane is wind speed.
A tropical storm has sustained winds of 39 to 74 mph, while a hurricane has sustained winds of at least 74 mph.
“Once the depression forms, the National Hurricane Center will then likely write a discussion about it and include probabilities of tropical storm or even hurricane formation, so stay tuned for that,” meteorologists said.
Storm Could Strengthen Before Weakening Near California
Current projections suggest the system could strengthen significantly later this week.
Meteorologists report that the storm could become a hurricane by Friday or Saturday. However, it may not maintain that strength as it moves closer to land.
Forecast guidance indicates the system could begin weakening Saturday night or early Sunday morning, potentially reaching Southern California as a tropical storm rather than a hurricane.
Even if the system loses hurricane strength, forecasters warn that it could still produce significant impacts.
The storm could bring heavy rainfall and extreme humidity across Southern California, with wet conditions potentially continuing into the following week.
That rainfall could create a risk of localized flooding, particularly in areas that receive persistent or especially heavy precipitation.
Tropical Storm Landfall in California Is Extremely Rare
A tropical storm reaching Southern California would be an unusual event.
Meteorologists emphasized that it is rare for tropical storms to make landfall in California. The last tropical storm to officially make landfall in the region occurred in 1939.
However, California has experienced impacts from tropical systems that weakened before reaching the coast.
“However, several tropical systems have weakened below tropical storm strength before making landfall,” meteorologists said.
One of the most recent examples was Hurricane Hilary in August 2023. Although Hilary produced significant rainfall and impacts across Southern California, it was no longer classified as a tropical storm when it reached California.
El Niño and Warm Ocean Waters Could Fuel Development
One factor attracting additional attention is the unusually warm water across the Eastern Pacific.
Meteorologists say the potential storm is being fueled in part by a “super” El Niño developing in the Pacific Ocean, a climate pattern associated with warmer-than-normal ocean temperatures in the region.
Southern California is currently experiencing a marine heat wave, with sea surface temperatures reportedly running 5 to 10 degrees above normal for this time of year.
Recent National Weather Service data puts ocean temperatures around 74 to 76 degrees along Los Angeles County beaches.
The NWS Climate Prediction Center has also indicated that El Niño could produce a very strong event during the Northern Hemisphere’s fall and winter.
Meanwhile, several Pacific storms are already generating increased swells along Southern California’s coastline, including Hurricane Karina, which was reported as a Category 1 hurricane and could strengthen further.
Residents Told to Watch Forecasts Closely
For now, meteorologists are emphasizing that the exact track and strength of the developing system could still change.
A tropical depression must first form before forecasters can determine how likely it is to become a tropical storm or hurricane and where it could ultimately travel.
That means residents should continue monitoring official forecasts as the system develops.
Even if the storm weakens before reaching California, heavy rain and unusually high humidity could still create significant problems.
With Southern California having experienced relatively few direct tropical-system impacts historically, the potential arrival of a tropical storm would represent an unusual weather event worth watching closely.
Would you be concerned if a tropical storm reached Southern California? Share your thoughts in the comments and stay tuned for updates as the forecast develops.