Thousands of firefighters battling a wildfire in northern California received some help from the weather Saturday morning, just hours after the blaze exploded in size, sending massive, swirling plumes skyward and scorching an area about the size of Los Angeles. The blaze was one of several tearing through the western United States and Canada, fueled by wind and heat. Cooler temperatures and an increase in humidity on Saturday could help slow the Park fire, the largest blaze so far this year in California, after its intensity and dramatic spread led fire officials to make unwelcome comparisons to the monstrous Camp fire. That fire burned out of control in nearby Paradise in 2018, killing 85 people and torching 11,000 homes. Weather conditions are easing up, but that may or may not have an impact on the fires, said Marc Chenard, a meteorologist at the National Weather Service in College Park, Maryland.