Effects Of El Niño On Patagonia’s 1997-’98 Climbing Season. Briefly explained, El Niño is a sporadic warm water current that flows clockwise from west to east along the equator and then south along South America’s west coast against the normal polar current. In an “El Niño year,” water temperature on the South American coast rises about 3°C, increasing rainfall significantly. Peru usually is the most severely affected country and influences in Chile decrease with higher southern latitudes.
According to locals, the winter of 1997 was mild and warmer than usual, and spring was rainy, also with temperatures above average. But then, after a still rainy January, almost three continuous weeks of good weather followed in February! El Niño revealed itself not only as a long period of good weather, but also with higher temperatures during 1997. The snow line on the Southern Patagonian Icefield was much higher this year than usual. Crossing the Icefield became a painful adventure. In February, Soames Flowerree (Chile), José Vélez (Ecuador), Derek Churchil (Chile) and Ralph Rynning (Norway), who crossed the Southern Patagonian Icefield from Jorge Montt Glacier to Paso del Viento, had to work very hard under lots of rain in January on Jorge Montt to make any advance over an awful crevasse labyrinth until they reached the plateau. Then, in February, good weather returned, and the sun soon melted what little snow was left, turning the usually flat icefield into an irregular suncup and crevasse-covered surface. Sometimes, they advanced as little as one kilometer in three hours.
The explanation for the good weather was a strong high-pressure system that positioned itself over the Southern Pacific Ocean in Patagonian latitudes, obstructing bad-weather fronts on their way from west to east toward Patagonia. The origin of this high-pressure area might be very related to El Niño. Weather in central Chile is mainly regulated by a high pressure area over the Southern Pacific Ocean in front of the Chilean coast. It moves north in winter and south in summer. This year, probably due to the influences of the higher temperatures brought by El Niño, the high-pressure area moved farther south than usual, bringing good weather to Patagonia.
The climbing season in Fitz Roy and Cerro Torre areas also was different than usual. Although good weather was by itself a blessing for climbers, approaching the peaks was unusually difficult because of the low amount of snow on the glaciers, as well as the lack of ice holding together rotten rock sections on the approaches to some walls.
Torres del Paine, on the other hand, was not as affected by the conditions, as it is at a lower altitude than the Fitz Roy area. There was good weather during the first three weeks of February, too, but the most important influence of El Niño occurred during the last week of the month. Unprecedented rain and thunder flooded the park, forcing local authorities to evacuate people and close the park entrance.
Christian Oberli, Club Alemán Andino, Chile