US Gulf Faces Heavy Rain Threat From Developing Tropical System

A tropical system developing in the Bay of Campeche may reach the US Gulf Coast this weekend, threatening heavy rain while potentially skirting major oil and gas hubs.

The swirl of showers and winds has a 90% chance of becoming a tropical depression in the coming days, the US National Hurricane Center said on Monday. A depression is the weakest of a class of storms that also includes tropical storms and hurricanes. It won’t be named until its winds reach 39 miles (63 kilometers) per hour and would likely be called Isaias.

“We have it becoming a tropical storm in the next day or so,” said Alex DaSilva, lead hurricane meteorologist at commercial forecaster AccuWeather Inc. He said landfall was most likely near the Alabama-Mississippi border around midday Saturday, though the timing and location could shift depending on how quickly the storm moves north.

If the forecast holds, the system would pass east of the heart of US offshore oil and gas production and stay away from many of the largest refineries and processing plants in Texas and Louisiana.

The Atlantic season has lagged well behind its usual pace. Eight named storms have formed, a total typically reached by Sept. 9, but none have become a hurricane. By early October, an average season has produced about 11 named storms, including five hurricanes and two major hurricanes.

Strengthening El Niño conditions have increased wind shear and helped suppress activity across the basin. Shear occurs when winds change speed or direction at different altitudes and can disrupt a storm’s structure. Warm Gulf waters will provide ample fuel, but the system is expected to encounter stronger shear as it traces a long J-shaped track from coastal Mexico to the US Gulf Coast, limiting its ability to intensify, DaSilva said.

Rain will likely be the biggest threat, but because the storm is expected to interact with a dip in the jet stream, there is also the potential for tornadoes primarily east and south of its track, he said. In addition, there will be a chance of heavy rain as far north as Virginia as the storm moves inland.