El Niño is putting on a show at Iguazu Falls, which is now flowing at six times the normal rate and closed to tourists after heavy rainfall. Argentina's National Meteorological Service says the above-normal rainfall is driven by a strengthening El Niño, which NOAA says has as high as an 83% chance of being the biggest on record. The same pattern is drying out the Amazon basin — a reminder that El Niño cuts both ways.