As Hurricane Hilary continues to strengthen and move northward, it is now likely to cause hurricane conditions in Baja California on Saturday night and a rare tropical storm in southern California on Sunday, say forecasters from the United States National Hurricane Center (NHC).

At 9 a.m. Mexico City time, the NHC reported that Hurricane Hilary had become a powerful Category 4 hurricane, with sustained winds of up to 145 miles per hour. It was located about 360 miles south-southwest of Cabo San Lucas, Baja California Sur, and moving northwest at 10 miles per hour.

Forecasters had originally predicted that the hurricane would continue to intensify through Friday before weakening on Saturday. However, the NHC has now updated previous forecasts to warn that it will likely remain a hurricane by the time it makes landfall on Mexico’s Baja California peninsula on Saturday night, where it will continue northwards faster than expected.

The Mexican government has issued a Hurricane Warning for the region of the peninsula between Punta Abreojos and Punta Eugenia, and a Hurricane Watch for the area north of Punta Eugenia to Ensenada. A Hurricane Warning implies that hurricane conditions are expected within the next 36 hours and “preparations to protect life and property should be rushed to completion.”

“Don’t leave your house unless it is necessary, check the condition of your dwelling and if you need it, together with local councils we will have a network of refuges to take shelter,” said Baja California Governor Marina del Pilar Ávila Olmeda, in a video shared on social media. 

The National Center for Disaster Prevention (Cenapred) also recommended residents of high-risk areas move to temporary refuges managed by the Civil Protection unit. These refuges are usually located in public buildings such as schools and churches considered sufficiently secure to withstand extreme conditions. 

The NHC warned that the hurricane could bring rainfall of up to 10 inches, potentially causing flash flooding; a storm surge and coastal flooding along the peninsula’s west coast; and large swells causing “life-threatening surf and rip current conditions.”

Hillary is expected to reach the southwestern U.S. on Sunday, becoming the first tropical storm southern California has seen since 1939. Although less severe than a hurricane, these conditions are still likely to cause significant impact, with rainfall of 3 to 6 inches and isolated pockets of up to 10 inches. 

Tropical storm advisories are currently in place for the south of the Baja California peninsula, Mexico’s west coast north of Huatabampito, Sonora, and the region north of Ensenada into the U.S., as far north as the Orange/Los Angeles County line. 

With reports from Associated Press and Milenio