Bracing for impact: Gulf Coast taking hit from Cat 2 Hurricane Delta

Alex Sosnowski

Heavy rain bands and tropical-storm-force winds lashed the Gulf Coast on Friday as Hurricane Delta, chugging along at 14 mph, made its final approach. Delta's impacts along the Gulf Coast grew more prominent from daybreak on, and were visible on weather radar, as the hurricane crept ever closer to landfall along the storm-battered Gulf Coast.

AccuWeather forecasters said that by mid-day, about two-thirds of Delta's rainfall had already come ashore, but a "big eyewall blast" of rain still loomed for the coastline.

By late Friday afternoon, Delta was churning about 35 miles south of Cameron, Louisiana, the town where Hurricane Laura made a devastating landfall in late August. Delta's peak winds had decreased to 105 mph, making it a Category 2 storm, and down from 120 mph (Category 3) earlier in the morning.

Hurricane Delta had restrengthened into a Category 3 storm, packing maximum sustained winds of 120 mph, over the warm waters of the Gulf of Mexico on Thursday afternoon. The 4 p.m. CDT Thursday upgrade of Delta back into major hurricane force came after NOAA's Hurricane Hunters flew through the storm and found strengthening.

Delta is forecast to hit with Category 2 intensity as it charges toward southwestern Louisiana and encounters cooler water closer to the coast late Friday. It will be the 10th named storm to strike the United States, the seventh to make landfall along the Gulf Coast and the fourth to make landfall in Louisiana this hurricane season.

The storm took a northward turn early Friday morning, with the likelihood of a turn more to the northeast on Friday afternoon. The predicted track places communities from southwestern to south-central Louisiana in the path of the worst conditions forecast. The core of the hurricane's wind, rainfall and storm surge would be steered east of Texas with the anticipated path.

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However, forecasters said Delta's rain and wind field will continue to grow in size as the hurricane continues to move along at a steady pace.

This image, captured on Friday morning, October 9, 2020, shows Hurricane Delta over the northwestern Gulf of Mexico and on its way into southwestern Louisiana. (CIRA at Colorado State/GOES-East)

Squalls containing torrential downpours, gusty winds and even severe thunderstorms will increase in frequency along the northwestern and central Gulf coast area of the U.S. as seas and surf build through Friday.

Buoy observations just north of the eye registered wave heights of 35 feet during Thursday night.

A rise in water levels began along the upper Gulf on Thursday morning, and levels will continue to ratchet up into Friday evening, especially along the Louisiana coast.

Delta has undergone some weakening as forecast prior to making landfall in the U.S. Friday evening, and is expected to make landfall as a Category 2 hurricane in Louisiana. Therefore, the storm has now been rated a 2 on the AccuWeather RealImpact™ Scale for Hurricanes based on anticipated storm surge, high winds, flooding rainfall and a number of other economic factors. This scale, developed by AccuWeather, provides a more comprehensive outlook for impacts from tropical storms and hurricanes on land areas than the Saffir-Simpson Hurricane Wind Scale, which is based solely on wind speed.

During Friday evening, as Delta moves onshore, life-threatening storm surge, destructive winds and torrential rainfall will commence along the south-central and southwestern Louisiana coast.

"Delta is expected to bring a very dangerous maximum storm surge of 6-10 feet with the highest values near and to the right of where the hurricane makes landfall, especially for inlets and bays where water can become funneled, creating a rapid rise in water levels," AccuWeather's top hurricane expert Dan Kottlowski said.

It is important to note that there will be waves on top of the storm surge that can cause Gulf water to enter the second story of buildings.

The forecast track should keep the worst impacts west of New Orleans, but communities from Lake Charles to Lafayette, Louisiana, can be hit especially hard with extensive property damage and power outages from a combination of high winds, torrential rain and flooding along this portion of the Interstate-10 corridor in Louisiana.

Hurricane-force wind gusts of greater than 74 mph can extend inland through much of central Louisiana.

"The strength of the wind will lead to widespread damage to trees, power lines, weaker buildings, roofing and structures, including in some of the same areas impacted by Hurricane Laura in late August," Kottlowski explained.

Trees may block streets and secondary roads in the aftermath of the hurricane, with power outages expected to last many days, if not weeks, in some of the hardest-hit communities.

Sometimes, as hurricanes make landfall and move inland, tornadoes and waterspouts can be spawned. The risk of violent thunderstorms exists into Saturday, especially along the I-10 corridor in Louisiana and Mississippi.

Rainfall on the order of 4-8 inches will be widespread over central Louisiana. Delta's fast pace should prevent a repeat of staggering rainfall amounts and flooding from Harvey in 2017 or a lesser extent from Marco, Sally and Beta this year. Still an AccuWeather Local StormMax™ rainfall of 16 inches is forecast over south-central Louisiana.

The bulk of the rain and wind will occur from Friday afternoon to Saturday midday in Louisiana. Forecasters and officials urged residents to heed all warnings during and after the height of the storm, including staying off roads as the storm rages through the region.

In addition to the threats from storm surge, high winds and flooding rainfall, there is the potential for tornadoes near and east of the center of Delta as it makes landfall and moves inland.

The greatest risk of tornadoes will occur from south-central Louisiana to southern Mississippi and perhaps the Alabama Panhandle. The thunderstorms capable of spawning tornadoes can be fast-moving. Any tornado can strike with very little to no notice.

Although the storm will lose some wind intensity prior to landfall, forecasters and officials alike say Delta should be considered a dangerous threat to the U.S.

On Tuesday, Delta's intensification was the most extreme in 15 years for an October hurricane. The storm's maximum sustained winds increased by a whopping 70 mph - from 40 mph to 110 mph - in its first 24 hours as a named storm. Only Hurricane Wilma in 2005 exploded in a more significant fashion over that same 24-hour period. Delta has also set a speed record for strengthening from a depression to a Category 4 hurricane. Delta accomplished this in just over 36 hours, surpassing Keith from 2000, which did so in 42 hours.

Hurricane Delta quickly strengthened into the second-most intense hurricane of the 2020 Atlantic hurricane season on Tuesday as its maximum sustained winds reached 145 mph. The only storm to become stronger this season was Hurricane Laura, which packed peak winds of 150 mph.

Along the Gulf Coast, Delta is expected to behave differently than Laura from August. Laura was strengthening upon landfall and reached Category 4 force before roaring ashore.

"As Delta approaches the upper Gulf Coast, it will start to encounter increasing wind shear and slightly cooler water, which should wear on the storm and start a weakening process," Kottlowski stated earlier this week.

That weakening trend has begun, but people should not let their guard down as Delta will still be a formidable hurricane in Louisiana.

Wind shear is the increase in wind speed with altitude as well as the sudden change in wind direction from one location to another. Wind shear and changes in the structure of the eye are some of the main challenges in forecasting the overall strength of hurricanes.

"The forward speed of Delta and the degree of shear it encounters will determine its wind strength at landfall Friday evening," Kottlowski explained.

"Regardless of a loss in wind intensity near the core, surge and wind impacts will still be potentially devastating along and near where the hurricane makes landfall along the central Gulf coast Friday afternoon and evening," Kottlowski added.

Similarly, Delta weakened Tuesday night into Wednesday morning as it tracked closer to the northeastern part of the Yucatan Peninsula, eventually making landfall in Mexico around 5:30 a.m. CDT Wednesday near the town of Puerto Morelos, south of Cancun along the Riviera Maya. At the time of landfall, Delta was a strong Category 2 storm with maximum sustained winds of 110 mph, just 1 mph below major hurricane strength. Extreme Meteorologist Reed Timmer reported from Cancun for AccuWeather as the hurricane lashed the region.

Timmer reported pockets of extreme damage, including significant structural damage, in the region as he surveyed the scene on Wednesday, noting that Delta's winds were enhanced as they had funneled through buildings. He shared several videos showing complete destruction along the waterfront of Cancun.

U.S. officials aren't taking any chances with the storm and have been in full preparation mode this week. Hurricane warnings were in effect along parts of the northern Gulf Coast, from the Texas / Louisiana border eastward to Morgan City, Louisiana, as of Thursday morning.

A storm surge warning was issued from High Island, Texas, to the Mouth of the Pearl River, Louisiana, including Calcasieu Lake, Vermillion Bay and Lake Borgne. The Storm Surge Warning for Lake Pontchartrain and Lake Maurepas was canceled early Friday morning.

Tropical storm warnings were also posted for areas from Galveston, Texas, to New Orleans, Lake Pontchartrain and Lake Maurepas.

State and local agencies were preparing in Louisiana, with sandbagging efforts and by shoring up levees. Gov. John Bel Edwards began urging residents to prepare early on Tuesday and later on declared a state of emergency in Louisiana.

The coronavirus pandemic, which has been complicating hurricane response amid the extremely active hurricane season, will continue to create hurdles in the coming weeks. Coronavirus testing will be suspended on Friday and Saturday in parts of Louisiana due to Delta's arrival, according to Edwards.

Alabama Gov. Kay Ivey declared a state of emergency midday Tuesday ahead of the hurricane, noting that coastal areas of the state are still recovering from Sally's blow in mid-September. Hurricane Delta "could potentially have a significant impact" on Alabama, she tweeted.

Delta will be the 10th named tropical system to strike the U.S. in 2020, which will break the record of nine storms to make landfall in the continental U.S. in one season. The record was tied recently when Beta made landfall along the Gulf Coast of Texas and was previously set in 1916. Delta will also be the fourth named system to threaten Louisiana, following landfalls from Cristobal, Marco and Laura earlier this season.

"Since 1964, there have only been three hurricanes to make landfall along the Louisiana coast during October," according to AccuWeather Senior Meteorologist and Forecasting Manager Dan DePodwin.

"Those hurricanes were Lili from 2002, Juan from 1985 and Hilda from 1964," DePodwin said. Hilda hit as a major hurricane.

AccuWeather users can track Delta from home using our local hurricane tracker pages that provide detailed information about a specific location. Click on the city name to track how Delta will impact each place as it churns northward:

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