A record-setting tropical storm formed in the East Pacific Tuesday, nearly a week before the official start to hurricane season for that region.

Tropical Storm Adrian is expected to strengthen into a hurricane and threaten Mexico by early next week, according to the Miami-based National Hurricane Center. Hurricane season for the Eastern Pacific officially begins on May 15, while the Central Pacific season begins June 1.

This is the earliest known tropical depression to form in the East Pacific during the “satellite era,” according to the center’s scientists. The previous earliest tropical storm in the region was recorded on May 12, 1990.

At 5 a.m. today, Adrian was about 435 miles south-southeast of Santa Cruz, Mexico, with maximum sustained winds of 45 mph, 5 mph stronger than Tuesday, and moving northwest at 7 mph, forecasters said.

Forecasters said the storm could become a Category 1 hurricane, with winds of at least 74 mph, by Saturday.