Willa is expected to come ashore on Tuesday afternoon or evening local time (Tuesday night or Wednesday morning British time).
"Willa is an extremely unsafe category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale".
Willa had maximum sustained winds of 155 mph (249 kph) early Monday and was centered about 195 miles (315 kilometers) south-southwest of Cabo Corrientes. Hurricane force winds extended out 25 miles from the storm's core and tropical storm force winds were up to 80 miles out.More news: #MeToo: Anu Malik no longer part of 'Indian Idol'
As Willa strengthened, tropical storm Vicente continued to move offshore further south and is expected to weaken to a tropical depression before reaching land late Tuesday night. It predicted that Willa could become a Category 5 hurricane later Monday, generating life-threatening surf and rip tide conditions.
It will then weaken slightly before making landfall but will still be a unsafe hurricane when it does hit.
Willa is expected to deliver rainfall of up to 46cm (18in) along parts of south-west Mexico, the NHC said on Monday, as it reported that the storm was carrying winds of 256km/h (160mph).
The NHC said "a risky storm surge" was also likely to affect coastal areas by Tuesday evening, adding that rain and strong winds would be accompanied by "large destructive waves".More news: Nigeria's Kaduna state: 55 dead after row at market
Some areas could see up to 18 inches of rainfall, likely triggering flash flooding and landslides in mountainous areas.
This image provided by NOAA on Monday shows Hurricane Willa in the eastern Pacific, on a path to smash into Mexico's western coast. Willa is also forecast to bring high winds and heavy rainfall.
Tropical storm warnings ranged from Playa Perula north to San Blas and from Mazatlan north to Bahia Tempehuaya, according to the Hurricane Center.
"There are no coastal watches or warnings in effect", said the NHC, but it stressed that "interests along the southern and southwestern coasts of Mexico should monitor the progress of Vicente".More news: Trump Administration Reportedly Trying To Take Transgender Protections ‘Out Of Existence’