Patricia, the most powerful storm ever in the Eastern Pacific and Atlantic basins, tops the list of the strongest hurricanes recorded anywhere in the world since 1970.
It will overtake Typhoon Haiyan, which killed more than 6,000 people in the Philippines in 2013.
Hurricane Patricia has predicted winds of 200mph. This makes Patricia a 'Category Five' hurricane as she has sustained winds of over 157 mph.
Patricia's wind speed is 25mph faster than hurricane Katrina's, and 15mph faster than Hurricane Wilma's, both of which struck in 2005. The fastest wind speed on record is 190mph for hurricane Allen in 1980.
Patricia is not expected to weaken much and will likely still be a Category Five when she makes landfall in southwestern Mexico.
Only one other Category Five hurricane has ever made landfall on the Pacific coast of Mexico.
This storm landed in October 1959 and killed about 1,800 people. The last time a Category Five hurricane threatened any part of North America was 2007 when Hurricane Felix was nearing Nicaragua.
Currently Hurricane Patricia has a central pressure of 880mb, meaning she now holds the record for lowest pressure in any hurricane on record.
Patricia broke the record of 882 millibars set by Wilma almost exactly 10 years ago.
Hurricane Patricia will not only bring a threat of strong winds, but also widespread flooding.
This will include dangerous storm surges, flash flooding, and mud slides. Jalisco, Michoacan, Guerrero, and Colima in Mexico are expected to see six to 12 inches of rain at least. Some estimates suggest rain fall could reach more like 20 inches.
In 2005, Hurricane Rita triggered the third largest evacuation in US history due to intense flooding. In Louisiana, swells reached depths of 180 inches.
Hurricane Katrina (2005) is the costliest Atlantic hurricane on record. It caused $125 billion in damage.
Despite only being a Category Three hurricane, Hurricane Sandy (2012) racked up the second largest bill, causing around $70 billion worth of damage. Hurricane Ike (2008), another Category Five hurricane, caused damages costing upwards of $35 billion.
Around four million people evacuated the Houston region ahead of Hurricane Rita in 2005.
How is Mexico preparing?
Mexican authorities declared a state of emergency and warned residents to prepare as Patricia approached the coast.
Home and shop owners along Mexico’s western coast stocked up on food and boarded up buildings in preparation.
Classes at schools in Jalisco and Colima were suspended and the airports in Puerto Vallarta and Manzanillo, closed.
Aside from mass evacuations, at CellMex Medical Clinic in Puerto Vallarta, medical staff are moving patients into the safest rooms of the hospital and advising all non-life-threatening patients to stay at home.