What does it mean when a hurricane undergoes 'rapid intensification'?

A GOES-East visible satellite image of Category 4 Hurricane Iota on Nov. 16, 2020, after it rapidly intensified over the Caribbean Sea.

(NOAA/NESDIS/STAR)

Hurricane Ida might undergo "rapid intensification" during its journey through the Gulf of Mexico.

This is a term used for tropical cyclones (tropical depressions, tropical storms and hurricanes) that – you guessed it – intensify at a rapid pace, but there is strict criteria a storm must meet in order to officially undergo rapid intensification.

According to the National Hurricane Center, rapid intensification occurs when a tropical cyclone's maximum sustained winds increase by at least 35 mph in a 24-hour period. 

The forecast issued by the NHC on Friday at 5 p.m. Eastern time suggests Hurricane Ida will rapidly intensify in the Gulf of Mexico. Its winds are predicted to increase from 80 mph to 120 mph between Friday at 5 p.m. Eastern and Saturday at 2 p.m. Eastern.

That's an increase of 40 mph in less than 24 hours, so the storm would officially undergo rapid intensification if this forecast turns out to be correct.

IDA TRIGGERS HURRICANE WARNINGS FOR GULF COAST AHEAD OF CATEGORY 4 LANDFALL IN LOUISIANA SUNDAY

Eric Blake, a senior hurricane scientist at the NHC, expressed his concerns on Twitter Friday morning.

"Ida has me very concerned this morning for Louisiana – you can’t ask for a worse recipe for a destructive hurricane," Blake tweeted. "Not much shear, and a track right up the deepest, very warm water (using ocean heat content). There is extremely serious high-end hurricane potential here!"

During the record-breaking 2020 Atlantic hurricane season, 10 of the 13 hurricanes that formed underwent rapid intensification, and a few of those underwent explosive intensification. This tied the previous record number of rapidly intensifying storms set in 1995, according to NOAA's National Centers for Environmental Information.

Hurricane Iota in November 2020 was one of the storms that rapidly intensified. In fact, Iota doubled the criteria for rapid intensification when its maximum sustained winds increased by 70 mph in just 24 hours.

Extreme rapid intensification rates like this are expected to become more common because of climate change, according to research by Kerry Emanuel, a hurricane scientist at the Massachusetts Institute of Technology.

By 2100, the frequency of a hurricane's winds increasing by at least 70 mph in the 24 hours leading up to landfall is expected to be once every five to 10 years, Emanuel noted. That would be an increase from a rate of once every 100 years in the late-20th-century climate.