Just when the Pacific’s so-called Super El Niño appeared big enough, the climate phenomenon seems to have sprouted a second arm. New sea-surface temperature maps show a broad ribbon of abnormally warm water stretching across the equatorial Pacific—and another tongue extending south from Peru and Ecuador toward Chile. Comparing maps from September 30 and October 14, the southern extension appears to have expanded dramatically. But this is no literal mutant, and “second arm” isn’t an official meteorological distinction. It describes the shape of the warming, not a separate El Niño event. The latest El Niño model from Peru’s meteorological agency, showing a “second arm” of oceanic warming. Senamhi The concern is the sheer scale of the heat.…