Hurricane Hilary, now a powerful Category 4 storm churning off Mexico’s Baja California peninsula, is making its way towards the Pacific coast. It’s projected to hit Southern California as a tropical storm — the first since 1939 — by Sunday night and into Monday, bringing high winds and the potential for dangerous flooding.

“Life-threatening and potentially catastrophic flooding likely over much of Baja California and Southern California this weekend and early next week,” the National Hurricane Center (NHC) said in a Friday afternoon advisory.

The NHC forecasts Hilary will make landfall in Baja on Sunday as a hurricane but lose strength as it makes its way north. It’s expected to hit Southern California as a tropical storm as early as Sunday. Hilary’s monsoonal rains will cause flash, urban and arroyo flooding with the potential for “significant impacts,” the NHC said.