September 27, 2021

Hurricane Sam Remains A Powerful Major Hurricane Over The Open Atlantic Ocean


Hurricane Sam spent more than 24 hours as a powerful category four storm this weekend as it churned out in the open Atlantic Ocean. The system was an absolute powerhouse for much of Saturday and Sunday, flirting with scale-topping category five intensity before the hurricane's structure stumbled on Sunday evening.

The latest update from the National Hurricane Center reported that Hurricane Sam's maximum sustained winds had dropped a bit to 145 mph by 11:00 p.m. on Sunday night, down from a maximum intensity of 150 mph earlier in the day. It's likely weakened some more since then given its ragged appearance on satellite imagery.


Hurricane Sam was a textbook example of rapid intensification if there ever was one. The system grew from a newly formed tropical storm to a hurricane in just about 24 hours.

The storm underwent another period of explosive intensification that began Friday evening and didn't finally level out until Saturday night when the storm reached solid category four intensity.

One of the great ironies of powerful hurricanes is that they're incredibly fragile systems. One hiccup can send them spiraling into a mess (can't we all relate these days?). That's what happened to Sam on Sunday night.

It's likely that Sam is undergoing an eyewall replacement cycle (ERC) right now, which occurs when the storm's eyewall degrades and is replaced by another, larger eye.

An ERC weakens a storm's winds and allows its minimum pressure to rise, all while redistributing its energy farther out from the center of the storm. This allows the hurricane to grow in size before potentially restrengthening once a new, stable eye emerges.


Hurricane Sam is one of the most impressive storms we've seen in the Atlantic Ocean in quite a while, and that's saying something given all the nonsense we've been through recently. It's a guilt-free gawk fest, one of the rare hurricanes in recent years we can admire without immediately cringing in fear.

Sam was a picturesque hurricane at its peak. The storm had a clear, bold eye that was surrounded by a dense core of ferocious thunderstorms fueling the system's immense power.

The near-symmetrical core of the storm vented into the upper levels of the atmosphere with a healthy outflow adorned by a beautiful plume of cirrus clouds that radiate clockwise from the eye of the storm. A hurricane's outflow exhausts air away from the eyewall so the storm is free to gather as much instability as it can from the warm ocean below.


The hurricane doesn't look that impressive anymore. Between the eyewall replacement cycle and possibly some wind shear throwing it off balance, Sam looks a little worse for wear tonight. Despite the storm's appearance, it remains a major hurricane.


Hurricane Sam is traveling around a large ridge of high pressure parked over the central Atlantic Ocean. It's crawling at just 7 mph, a relatively slow speed that's the result of weak steering currents hustling the storm along. 

Forecasters expect Sam to continue slowly lumbering along a northwesterly path that takes it safely clear of the Leeward Islands over the next couple of days.

While the storm will miss the Caribbean and likely won't have any direct impacts to the U.S. East Coast, this predicted path would bring the hurricane close to Bermuda by next weekend. We also have to watch where it goes from there for potential impacts in Atlantic Canada by the first week of October.


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I graduated from the University of South Alabama in 2014 with a degree in political science and a minor in meteorology. I ran Gawker's The Vane for two years and I've contributed to Mental Floss, Forbes, Popular Science, and the Washington Post's Capital Weather Gang. I also teamed up with Outdoor Life to write a book called The Extreme Weather Survival Manual, which came out in October 2015.

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