Forecasters announced Thursday that a potentially powerful El Niño event is developing in the Pacific Ocean, with a strong chance of becoming one of the most intense in the past 75 years. The National Weather Service's Climate Prediction Center reported above-average surface temperatures in the central and eastern Pacific, and conditions favoring El Niño are expected to strengthen in the coming months.
There is a 63% probability of a very strong El Niño during the November-January period, which would rank among the largest events since 1950.
For Southern California, this typically means dramatically increased precipitation, though forecasters caution that even strong El Niño events do not always produce the expected impacts everywhere. However, stronger events can significantly tilt the odds in favor of wetter conditions.
Typical effects include stormier weather across the southern United States, with more rain and snow, as well as an elevated risk of flooding during high tides along the West Coast. Harmful algae blooms are also a potential concern.
The El Niño pattern is expected to shift the jet stream southward over the northern Pacific, leading to drier conditions in the Northern Rockies and the Ohio and Tennessee valleys, while bringing stormier weather to southern regions. NWS Director Ken Graham emphasized that every El Niño is unique, but advanced monitoring and improved understanding allow for better predictions and public preparedness.