Explosive Cyclogenesis – This Week’s Atlantic Bombs

by Chris Dixon


The classic swirl of a huge open ocean storm. Notice the bright white at the base of the comma, that’s remnant energy and moisture from Tropical Storm Faye feeding the beast. Image: NOAA Ocean Prediction center.

Today, Washington Post Weather Editor Jason Samenow posted up a remarkable little story that depicted the development of a mammoth storm in the open Atlantic Ocean. A storm whose category 3 force winds are generating a vast wave field that will soon be blitzing the European coast – including the ASP’s Moche Rip Curl Pro Portugal – with the first major swell of the 2014/2015 winter.


Tuesday morning’s view of the storm, with ex-tropical storm Faye at the very tail end.
Image: NOAA Environmental Visualization Laboratory.

The storm formed as a cold front pushed off the U.S. east coast and then tapped into the moisture plume and energy of Tropical Storm Faye. On Sunday night into Monday, the storm inhaled Faye’s energy and wound up into a tight spiral as the central barometric pressure fell precipitously, a condition meteorologists call “explosive cyclogenesis” or more simply, “a bomb.” This happens when a storm drops by 24 millibars in a 24 hour period. In the case of this storm though, the pressure dropped by 46 millibars, eventually bottoming out at 948, or 29.92 inches of Mercury – with winds of a category 3 hurricane. This is extraordinary when you consider that the October “Perfect Storm” of 1991 only dropped to 972 mb. Hurricane Sandy on the other hand, dropped to a slightly lower 940 millibars, and we all know how that turned out.

Here’s a video from NOAA from Oct 13, 2014.

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This animation shows the development of a hurricane force low in the Atlantic through the SEVIRI RGB Air Mass product and the Geocolor imagery. In addition, Hurricanes Fay and Gonzalo are shown to the south of it.



This image, taken on Tuesday, October 14, shows the storm just south of Greenland – wound up even more tightly. Fortunately, the storm is forecast to weaken before strafing the northern British Isles Friday into Saturday.


October 14, 2014 Image: NOAA Environmental Visualization Laboratory.

Next on tap though, will be Hurricane Gonzalo (just above Puerto Rico in the below image), which is well on its way to category 4 status. When Gonzalo merges with a front coming off the U.S. into this weekend and pushes out into the open Atlantic, I would not want to be anywhere nearby – particularly on the island of Bermuda. Meanwhile, check out how big the European storm has become.

It literally spans the entire north Atlantic.  — CD

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