Tropical Storm Delta rapidly intensifies, likely to hit U.S. Gulf Coast as hurricane
The record-shattering 2020 Atlantic hurricane season shows no signs of slowing down. Tropical Storm Delta formed early Monday morning, just south of Jamaica in the Caribbean, and by Monday evening it was already near hurricane strength. As of the 5 p.m. advisory from the National Hurricane Center the system has winds of 70 mph — only 4 mph shy of a hurricane — having rapidly intensified 25 mph in just 6 hours.
The storm is now forecast to become a major Category 3 hurricane Tuesday and impact the U.S. Gulf Coast by the end of the week.
Delta is the 25th named storm of the season, 6 full weeks ahead of the record pace set in 2005 — a season that featured 28 tropical systems. With nearly two months left in the season, and three months left in the year, 2020 is on track to leave 2005 in the dust. It’s only the second hurricane season on record to.
Delta follows right on the heels of Tropical Storm Gamma, which is still spinning about 600 miles to the northwest of Delta, near Cancun, Mexico. Gamma is forecast to continue to weaken, as Delta becomes the main event in the Caribbean.
As of Monday morning, hostile upper-level winds, also called wind shear, which were inhibiting the system from organizing, have started to lessen. In response, Delta is quickly becoming better organized as thunderstorms blossom and encircle the center of low pressure.
As a result Delta has now entered its strengthening phase, which is expected to last through Wednesday as the system moves northwestward near Cancun and then into the Gulf of Mexico. The computer model intensity guidance, as well as real-time data, suggests that rapid intensification will continue overnight, a phenomena that is becoming more common in the Atlantic due to warmer ocean temperatures from climate change.
The definition of rapid intensification is a 35 mph jump in winds within 24 hours. With its 25 mph spike in 6 hours, Delta is on pace to nearly triple the definition of rapid intensification.
The official forecast from the National Hurricane Center is for Delta to become a Category 3 hurricane Tuesday with winds of 120 mph as it passes through the Yucatan Channel, west of Havana, Cuba. On Wednesday it is forecast to maintain winds of around 120 mph, but an even stronger storm is not out of the question.
Various factors are favorable for the system to become a major hurricane. As of early Monday evening, the storm’s relatively small eye has closed off, enabling the system to gain a faster spin. Above the storm the atmosphere is very calm, acting like an incubator. Lastly, over the next 48 hours the system will be moving over the northwest Caribbean into a bullseye of some of the most potent ocean heat content on Earth. Not only is it very hot water, 86 to 88 degrees Fahrenheit, but also very deep hot water, which also helps sustain and strengthen storms.
The initial stages of this system bear some resemblance to Hurricane Wilma, which formed in mid-October 2005. To this day, Wilma is the most intense Atlantic hurricane on record with a pressure of 882 millibars. While it was located near Delta’s present position, Wilma shattered records for rapid intensification, dropping almost 100 millibars in 24 hours and strengthening from a tropical storm with winds of 70 mph to a Category 5 storm with winds of 185 mph in just 36 hours.
While no two meteorological setups are exactly alike, it will not be surprising if Delta undergoes rapid intensification and becomes stronger than initially forecast. However, to replicate the extent of Wilma’s astonishing intensification would be statistically unlikely.
Delta is expected to reach peak intensity on Wednesday and Thursday as it enters the central Gulf of Mexico. Then all indications are that wind shear — those hostile upper-level winds — will develop on top of the system and should act to subdue the intensity of the storm.
The official forecast calls for the system to weaken some before making landfall Friday. Most models are in general agreement on the landfall occurring somewhere in an area stretching from the Louisiana coast eastward to Mobile, Alabama and Pensacola, Florida. But with four days to go, a lot can change between now and then. Residents along the Gulf Coast should begin making initial preparations now.
When Delta makes landfall, it will become the 10th tropical cyclone to make landfall along the U.S. coast this season, the most on record in the Atlantic.