A powerful El Nino has officially formed in the Pacific Ocean, with meteorologists warning Thursday that it is poised to reach historic strength and intensify extreme weather events across the globe.

The natural warming cycle is expected to exacerbate global temperatures, already elevated by fossil fuel emissions, and could supercharge severe weather patterns worldwide. The phenomenon is predicted to rival or even surpass the record-setting El Nino of 1997, which caused billions in damages through heatwaves, floods, droughts, tornadoes, and wildfires.

The U.S. National Oceanic and Atmospheric Administration formally confirmed the existence of the El Nino, a warming of the Pacific near the equator that profoundly affects global weather patterns. NOAA projects a 63% likelihood that this El Nino will become so intense by late fall and early winter that it “would rank among the largest El Nino events in the historical record going back to 1950.”

Clark University climate scientist Abby Frazier explained that the warm, deep waters of an El Nino introduce “a lot of extra heat to the surface, fueling a lot of extreme events for a lot of places around the world.” She cautioned that, particularly in the Pacific, “it can get dire very quickly.”

United Nations Secretary-General António Guterres echoed this urgency, describing El Nino as an “urgent climate warning” and stating that “El Nino conditions will pour fuel on the fire of a warming world.”

The weather pattern’s effects vary by region. El Nino often dampens — but doesn’t eliminate — Atlantic hurricane season activity, but increases it in the Pacific. So while the U.S. East and Gulf coasts may get a break, Hawaii and other islands are more in danger, Frazier said.

Read More: ‘Super’ El Nino is officially here: It could ‘get dire very quickly’