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.

Southern California was forecast to face more dangerous winds on Wednesday, but could get some badly needed rain this weekend, which could create new challenges like toxic ash runoff.

The National Weather Service issued a warning of a “particularly dangerous situation” for parts of Los Angeles and Ventura counties from Monday afternoon through Tuesday morning.