Firefighters on Sunday had battled more than a thousand wildfires burning throughout Northern California to a stalemate, but forecasters said dangerous fire conditions would not relent anytime soon. No new major fires had broken out Sunday as fire crews inched closer to getting some of the largest blazes surrounded, according to the state Office of Emergency Services. But a "red flag warning" - meaning the most extreme fire danger - was still in effect for Northern California until 5 a.m. Monday. The coming days and months are expected to bring little relief. Forecasters predicted more thunderstorms and dry lightning through Tuesday, similar to the ones that ignited hundreds of fires a week ago. Meanwhile, a U.S. Forest Service report said the weather would get even drier and hotter as fire season headed toward its traditional peak in late July and August. Lower-than-average rainfall and record levels of vegetation parched by a spring drought likely mean a long, fiery summer throughout Northern California, according to the Forest Service's state fire outlook released last week. Already the fires now burning will take weeks to months to fully bring under control, the report said. Those blazes were mostly sparked by lightning storms that were unusually intense for so early in the season. But summer storms would likely grow even more fierce, according to the Forest Service.

"Our most widespread and/or critical lightning events often occur in late July or August, and we have no reason to deviate from that," the agency's report said. The blazes have scorched more than 556 square miles and destroyed more than 50 buildings, said state emergency services spokesman Gregory Renick. Air quality districts from Bakersfield to Redding issued health advisories through the weekend, urging residents to stay indoors to limit their exposure to the smoky air. Air pollution readings in Northern California are two to 10 times the federal standard for clean air, state air regulators said. On Saturday, President Bush issued an emergency declaration for California and ordered federal agencies to assist in firefighting efforts in Butte, Mendocino, Monterey, Santa Clara, Santa Cruz, Shasta, and Trinity.