CORRIENTES, Argentina—Wildfires that have been ravaging northern Argentina for several weeks advanced relentlessly Sunday, although the light rains that began over the weekend gave some hope to firefighters. Corrientes Province is the most affected area, where officials said at least eight separate fires continued to burn and had devastated at least 9 percent of its territory. The flames are consuming about 30,000 hectares (89,000 acres) a day in Corrientes, destroying almost 800,000 hectares so far, according to the latest official reports. Strong winds, low humidity, and dryness from drought have helped the fires spread since mid-January. Forecasters said the light rains that were falling Sunday were expected to continue throughout the coming week. The mainly rural province of farms, ranches, and forests normally is characterized by abundant rain. “It never happened to us, we never lived something like this, we were really overcome,” said one resident, Jorge Ayala, Authorities estimate …