Tropical Storm Rosa diminished from a Pacific hurricane over the weekend, but will still bring strong winds and dangerous rip currents to southern California on Monday, the National Hurricane Center (NHC) said.
It could also bring life-threatening flash floods to central Arizona over the next few days, the NHC added.
“This storm still has a punch, it’s still dangerous,” said David Roth, a meteorologist with the National Weather Service’s Weather Prediction Center in College Park, Maryland.
Swells generated by Rosa on Monday are affecting the coasts of southwestern Mexico, the west coast of the Baja California peninsula and southern California through Tuesday, the weather service said in an advisory.
“We’re already getting rains in southern California through southwest Arizona,” Roth said.
Baja California and southern California could receive 3 to 6 inches of rain, with isolated spots of 10 inches in the next few days. The desert southwest of Arizona could get up to 4 inches of rain, potentially bringing flash floods and mud slides, Roth said.
Rosa was packing 50 mph (85 kmh) winds and was about 140 miles (225 km) west southwest of Punta Eugenia, Mexico at 2 a.m. Monday, Pacific time, the NHC said.
It is expected to diminish in strength as it makes landfall on Monday night and its remnants are expected to move across the southwestern desert on Tuesday.