Guillermo strengthened into a hurricane early Friday morning in the eastern Pacific Ocean.
When Guillermo reached hurricane strength, it became the fifth hurricane to develop in the eastern Pacific's 2015 Hurricane Season.
Guillermo is roughly 1,700 miles east-southeast of Hilo, Hawaii, and moving toward the west-northwest.
Hurricane Guillermo was showing better organization during the early Friday morning and reached Category 1 strength as sustained wind speeds exceeded 74 mph, the minimum speed for hurricane classification.
Further strengthening is expected as Guillermo will continue to move across warm ocean waters, as well as interact with a moist environment with little shear.
Hurricane Guillermo is expected to reach Category 2 or 3 strength over the next few days.
If this storm strengthens beyond a Category 2 storm, then it will be considered a major hurricane for the Eastern Pacific.
Although the track is certain over the short-term, it is less clear where it will head beyond 48-72 hours.
"It's unclear how strong it will be. What we do know is that, thanks to El Niño, sea surface temperatures are much warmer than normal," AccuWeather Meteorologist Anthony Sagliani said.
Guillermo is expected to encounter less favorable conditions in the long-term forecast beyond 72 hours, which will greatly diminish this storm's strength as it will be pulled apart by stronger wind shear.
The speed in which this storm will weaken will depend solely on how far north it tracks. The farther north it tracks, the more wind shear it will encounter and the quicker it will fade.
Due to track and intensity uncertainty beyond day three, it is unclear at this time if the Hawaiian Islands will be impacted by this tropical system.
"Guillermo will move northwesterly through the next several days on a track generally towards Hawaii. However, as the storm gets closer to Hawaii, wind shear to its north will increase and potentially hinder its intensity," Sagliani said.