Tropical Storm Bertha to weaken July 22-24; heat wave boosts Texas power prices

Tropical Storm Bertha may have reached its peak intensity offshore of the northern Gulf Coast, weather forecasters said July 21, but electric utilities along the westward forecast path continued to monitor the storm and prepare for any consequences.

Across 11 hurricanes affecting Atlantic and Gulf Coast regions from 2022 to 2025, loads dropped an average 20.2%, and power prices dropped an average 29.5%, S&P Global Energy data shows.

At the four affected locations where S&P Global Energy had natural gas power burn data, those numbers fell an average of about 20% from the same day a week prior. Across the region's relevant gas price points, Platts spot gas indexes from S&P Global Energy fell 12.5% from the same day a week prior.

But no trading was observed on the Intercontinental Exchange early July 21 for Southeast, Louisiana and Houston-area power markets in the storm's path. The National Weather Service's extreme heat warnings for the Dallas-Fort Worth area have boosted the Electric Reliability Council of Texas' North Hub day-ahead on-peak prices by about $15.75 to about $82.75/megawatt-hour in ICE trading early July 21 for delivery July 22.

'A weakening trend' seen

During a 10 am CT webcast, Jamie Rhome, the National Hurricane Center's deputy director, said that between a vertical sheer north of the storm, land interaction and dry air, "a weakening trend" should soon start. The storm should "continue to weaken as it sort of moves along the coast of southern Louisiana."

"Tropical storm conditions [are] spreading over portions of the Florida Panhandle," the bulletin said.

The storm's center was moving northwest around 5 mph, the bulletin said, but most of the heaviest rain was south of the center, the NHC said.

A tropical storm warning was in effect from the Bay-Gulf county line in Florida across the Alabama and Mississippi Gulf Coast to the Terrebonne-Lafourche parish line in Southeast Louisiana.

A tropical storm watch was in effect for metro New Orleans, Lake Pontchartrain and Lake Maurepas, plus the coast west of the Terrebonne-Lafourche county line to Southwest Louisiana's Vermilion-Cameron parish county line.

"On the forecast track, Bertha will move near or along the northern Gulf Coast during the next few days," the NHC said in its 1 pm bulletin. "Little change in strength is expected today, and gradual weakening is forecast Wednesday through Friday. Tropical-storm-force winds extend outward up to 90 miles from the center."

The 1 pm forecast map showed the storm's midpoint offshore due south of Alabama at 7 am CT July 22, near the mouth of the Mississippi in Louisiana about 7 pm CT July 22, and southeast of Lafayette, Louisiana, about 7 am CT July 23. By 7 pm CT July 23, the storm is forecast to have weakened to a depression due south of Lake Charles, Louisiana, and make landfall near Houston before 7 am CT July 25.

Utilities monitor storm

Entergy Louisiana and Entergy New Orleans, which serve most of the area in the direct path of the storm, had no plans to update on July 21 a news release issued July 20, which advised that they were "monitoring the tropical system in the Gulf and are preparing for severe weather that could impact our service territory in the next 48 hours."

They advised customers to assemble an emergency kit and "prepare for potential impacts."

As the storm approaches Texas, however, Houston's CenterPoint Energy said July 21 it has activated its Emergency Operations Center not just for the storm but also "as the hottest temperatures of the year so far may impact equipment in some areas on Tuesday and Wednesday ahead of any potential tropical impacts later in the week."

The company has activated about 1,050 frontline workers, with another 1,100 contractors available if needed, CenterPoint said in its news release.

In the release, Nathan Brownell, CenterPoint Energy vice president for resilience and incident commander, said, "Reaffirming our all-hazards approach to emergency preparedness, our team continues to take critical actions to prepare for both the current Tropical Storm Bertha in the Gulf as well as the hottest temperatures of the season."