Santa Ana winds will continue whipping through Southern California through Thursday, sparking fears that progress made fighting wildfires that have scorched over 40,000 acres and left 28 dead could be reversed and more blazes could break out.

Much-needed rain has begun to fall over Southern California, bringing relief to the drought-stricken region but also the threat of toxic runoff.

More rain fell Monday on parts of Southern California after causing mudflows over the weekend, helping firefighters but boosting the risk of toxic ash runoff in areas scorched by Los Angeles-area wildfires.

Rain brought much needed aid to the Los Angeles firefight, moving the fires surrounding the city closer to containment.

Southern California’s first rainy weekend of the winter has arrived. The rain event, months in the making, brought steady storms across the region as the Southland experiences drought conditions. The mostly welcome rain began Saturday night and is expected to sustain until Monday evening.