This year is chock-full of rapidly intensifying hurricanes - Jeff Masters

https://www.wunderground.com/cat6/maria-back-over-water-after-devastating-hit-puerto-rico
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If it seems like this year’s Category 4 and 5 storms made it to that level in a big hurry, you’re not imagining things. In the Washington Post, Chris Mooney spotlights a few of the leaps in strength that this year’s four major Atlantic hurricanes have taken, including:

Harvey: Cat 1 to Cat 4 in 24 hours
Irma: Cat 3 to Cat 5 in 24 hours
Jose: Cat 1 to Cat 4 in 24 hours
Maria: Cat 1 to Cat 4 in 12 hours, and Cat 1 to Cat 5 in 15 hours

Most of the rapid intensification records for major Atlantic hurricanes were set by 2005’s phenomenal Hurricane Wilma. However, Maria has tied Wilma for the fastest vault from tropical depression to Cat 5 hurricane (54 hours), as shown in Figure 5 above.