"The hurricane has less than a day to strengthen before the environment becomes less hospitable, with a notable increase in shear and decrease in water temperatures forecast this weekend", the National Hurricane Center said.
The east Pacific hurricane season, which starts on May 15 each year, has its first official hurricane.
In order for a hurricane to qualify as a Category 4 storm, it would have to produce winds between 130 to 156 miles per hour, according to NASA, and Aletta seems determined to top that category.
Aletta is located around 450 miles southwest of Manzanillo, Mexico. Infrared satellite images show the storm has a distinct, 20-mile wide eye, with deep convection.
To the southeast of Aletta, another area of disturbed weather is forecast to become a tropical depression or storm in the next 48 hours. The NHC said it's too early to tell whether the second system will pose a threat to the Pacific coast next week.
The west coast of Baja California Sur will be affected with high swells and rip currents this weekend.
The Weather Channel reported the average date when the first named storm forms in the Eastern Pacific Basin is June 10, according to NHS data from 1971 to 2009.