Hurricane Delta, which exploded into a major, Category 4 storm in the northwest Caribbean on Tuesday morning, is expected to slam ashore in coastal Louisiana unleashing a dangerous combination of damaging wind, flooding rain, and surging ocean water Friday into Saturday. Before that it will deal a serious blow to Cancun and the Yucatán Peninsula.
On Tuesday afternoon, Hurricane Delta continued to intensify, lurching from a 40 mph tropical storm to a 145 mph Category 4 in just 33 hours. Delta grew from a tropical depression to a Category 4 hurricane faster than any storm on record in the Atlantic according to Sam Lillo, a postdoctoral research at NOAA.
Hurricane rapid intensification is more likely in a warming world, and Delta is the sixth 2020 storm to experience such a leap in strength.
Delta is forecast to strike Cancun and the Yucatán Peninsula on Wednesday with maximum sustained winds of 155 mph, just shy of Category 5 intensity.
From there, it could reorganize and mark the second time this season a Category 4 hurricane has churned over the Gulf of Mexico. The storm is anticipated to weaken to a Category 2 or 3 before slamming into Louisiana, which has been hit hard by several storms this season.
The National Hurricane Center is urging much of the northern Gulf Coast from Louisiana to the Florida Panhandle to carefully monitor the storm. Although landfall along the coast of central Louisiana is most likely, shifts in the track are possible and impacts will be felt at considerable distances from where the center crosses the shore.
“There is an increasing likelihood of life-threatening storm surge and dangerous hurricane-force winds, especially along the coasts of Louisiana and Mississippi, beginning on Friday,” the Hurricane Center wrote, stating it will likely issue hurricane watches for the northern Gulf Coast on Wednesday.
New Orleans, which has been sideswiped by several storms this year, could be more directly impacted by Delta. However, on Tuesday the predicted track for Delta shifted more to its west, placing the coast of central Louisiana at greater risk. The National Weather Service office serving New Orleans cautioned “impacts - some significant - still remain a real possibility,” despite the shift.
Hurricane Delta now
Hurricane warnings are in effect for the Yucatán Peninsula between Tulum and Dzilam, Mexico, as well as Cozumel. That’s where the National Hurricane Center warns that “extremely dangerous storm surge and hurricane conditions are expected,” with the potential for “areas of significant flash flooding” inland as well.
Tropical storm warnings cover portions of western Cuba.
As of 5 p.m. Tuesday, Delta was centered 215 miles east-southeast of Cozumel, Mexico and was barreling west-northwest at 17 mph.
Despite its impressive strength, Delta is a small hurricane with a pinhole eye just 5 to 6 miles wide. Its hurricane force winds extend outward only 25 miles from the center.
On approach to the Yucatán Peninsula, the storm could strengthen even more and will probably be a high-end Category 4 storm early Wednesday as it nears landfall. Intensification to Category 5 strength cannot be ruled out.
The storm is expected to weaken as it passes over the Yucatán but the Hurricane Center projects re-strengthening when it emerges over the warm waters over the southern Gulf of Mexico Wednesday night and Thursday.
After that, hostile upper level winds and cooler waters are forecast to weaken the storm some. But the Hurricane Center cautions that computer models forecast “a significant increase in the size of Delta’s wind field while it is over the Gulf of Mexico, which increases the spatial extent of the storm surge and wind threats for the northern Gulf coast.”
Impact to Mexico
There is a growing chance that Delta could be devastating in Mexico’s Yucatán Peninsula, with winds gusting over 140 mph in the hurricane’s eyewall. Because Delta’s radius of maximum winds is so small but potent, subtle shifts in the storm’s track will have enormous bearings on impacts.
Right now, it appears the popular vacation resort city of Cancun could endure a close pass or direct hit from the still-strengthening cyclone. Cancun, whose economy is largely structured around tourism, has already suffered a major reduction in revenue due to the covid-19 pandemic.
Equally dangerous will be the 7- to 11-foot storm surge forecast by the National Hurricane Center. The surge will primarily occur near and just to the right of the eye. “Near the coast, the surge will be accompanied by large and dangerous waves,” warned the National Hurricane Center.
Dozens of resorts occupy the “Hotel Zone” of Punta Cancun, the barrier island a few miles east of downtown Cancun. The island sits just above sea level.
A half a foot of rain with localized 10-inch amounts can be expected, as well, coming just days after Tropical Storm Gamma drenched the region. Conditions in the Yucatán Peninsula are forecast to rapidly deteriorate on Tuesday evening and night, reaching their worst overnight before the storm subsides there late Wednesday morning.
Delta could become the strongest hurricane to strike Cancun since Wilma in 2005.
Concern growing for U.S. Gulf Coast
The area at greatest risk for landfall is southern Louisiana, which is very prone to storm surge flooding. The Route 90 corridor in coastal Louisiana, which traverses communities like Morgan City, may have to be partially evacuated.
On Thursday the projected track of Delta shifted a bit to the west, which means areas of coastal western Louisiana, which were devastating by Hurricane Laura have an increasing chance of storm impacts. However, the worst conditions are likely to focus just to the east of where the center comes ashore. It may take until Thursday before forecasters can pinpoint the areas likely to be hardest hit.
Wind gusts topping 90 or 100 mph are possible in some areas, along with a swath of 6 to 10 inches of rain and a dangerous storm surge near the coast. Tornadoes may become a concern as well.
The worst is expected to come Friday evening into early Saturday for the U.S. Gulf Coast. Thereafter, Delta will weaken quickly as it moves inland, becoming a tropical rainstorm and drenching the lower Mississippi Valley.
Delta in historical perspective
The 2020 hurricane season continues to smash and obliterate records, the oceans cranking out tropical storms and hurricanes like a factory. The high number of systems has forced meteorologists to exhaust their hurricane naming list and revert to the Greek alphabet for only the second time on record. And the pace of this year’s storm formation is unlike anything seen before; the only other time that we’ve reached a storm named Delta, in 2005, it didn’t occur until mid-November.
When Delta makes landfall, it will break the record for most named storms to strike the United States in a calendar year, surpassing the nine that came ashore in 1916.
Delta’s 70 mph leap in intensity between Monday morning and Tuesday morning is second fastest on record for an October hurricane in the Atlantic, only trailing Wilma in 2005.
When Delta was upgraded to a hurricane on Monday, it became the ninth to form in the Atlantic in 2020. “Only 3 other years in the satellite era (since 1966) have produced 9 or more Atlantic hurricanes by October 5: 1995, 2004, and 2005,” tweeted Phil Klotzbach, a hurricane researcher at Colorado State University.
With its winds of 145 mph, Delta is the strongest hurricane named using the Greek alphabet on record.