Such explosive strengthening is known as "rapid intensification," defined by the National Hurricane Center as having its wind speed increase at least 30 knots (35 mph) in 24 hours. "There is the potential for Irma to ramp up to an even more powerful hurricane into early week," according to AccuWeather Hurricane Expert Dan Kottlowski. Hope it's a "fish storm" pic.twitter.com/w6rWbbGVts 
 
 Irma was designated a tropical storm Wednesday morning, and by Thursday afternoon, it had strengthened into a large Category 3 hurricane, with winds of 115 mph.
– As Texas still deals with the devastation from Harvey, another weather system churning in the Atlantic, and moving west toward the US, has some worried. CNN reports on Irma, currently a Category 3 hurricane that experienced "rapid intensification" from Wednesday into Thursday, meaning its wind speed ramped up at least 35mph in that period—though the National Hurricane Center on Thursday noted the "remarkable" increase measured 58mph. A National Hurricane Center alert issued early Friday pegs maximum sustained winds at 115mph, with higher gusts. The storm is expected to approach the Caribbean by Tuesday or so as a Category 4 storm, then possibly the US—though meteorological models with wildly different scenarios show it's too early to make any definitive predictions on where the storm will land. Irma is what's called a "Cape Verde" hurricane, meaning one that forms off the coast of Africa then shoots across the Atlantic; CNN notes these storm systems can turn into particularly powerful ones (Hurricane Hugo is one example). What's emboldening Irma is a lack of the "hurricane kryptonite" known as wind shear, which often acts to tamp down hurricanes. A powerful high-pressure ridge is pushing Irma westward and keeping wind shear low. What one of the models is showing that has some concerned, per Reuters: Irma could head straight into the Gulf of Mexico, which could be bad news for areas still struggling after Harvey. "All interests in the eastern Caribbean will need to monitor the progress of this evolving and dangerous hurricane," an AccuWeather hurricane expert notes, reiterating he can't say "with certainty" how the US will be affected.