The meanest, most-quickly-intensifying hurricane in the Western Hemisphere.

Dr. Jeff Masters at Weather Underground has a lot of superlatives for Hurricane Patricia, the Category 5 storm that leapt up out of nowhere to devastate Puerto Vallarta:

Stunning, historic, mind-boggling, and catastrophic: that sums up Hurricane Patricia, which intensified to an incredible-strength Category 5 storm with 200 mph winds overnight. At 2:46 am EDT October 23, 2015 an Air Force hurricane hunter aircraft measured a central pressure of 880 mb in Patricia, making it the most intense hurricane ever observed in the Western Hemisphere. The aircraft measured surface winds of 200 mph, which are the highest reliably-measured surface winds on record for a tropical cyclone, anywhere on the Earth. The previous strongest Eastern Pacific hurricane was Hurricane Linda of 1997, with a pressure of 902 mb (estimated from satellite imagery.) The strongest Atlantic hurricane on record was Hurricane Wilma of 2005, with an 882 mb central pressure. Patricia does not beat the record-lowest pressure in the Western Pacific, though, which is held by Super Typhoon Tip of 1979: 870 mb.

Patricia is estimated to have intensified 85 knots (100 mph) in 24 hours, from a tropical storm to a Category 5 hurricane. In the Eastern Pacific, Hurricane Linda of 1997 is the only storm on record to have intensified at this rate. The Atlantic’s record holder for largest wind increase in 24 hours is held by Hurricane Wilma of 2005, which intensified from a 60-knot tropical storm to a 150-knot Category 5 hurricane–an increase of 90 knots (105 mph). Air Force reconnaissance observations indicated that the eye of Wilma contracted to a diameter of 2 n mi during this time; this is the smallest eye known to National Hurricane Center (NHC) staff. Patricia’s eye diameter was 8 miles at it’s peak strength.

Plenty more figures – and some stunning (historic, mind-boggling) imagery – at the link.