Tropical Storm Isaias forecast to become first Atlantic hurricane of 2026

Tropical Storm Isaias has formed in the Gulf of Mexico and looks likely to strengthen into the first Atlantic hurricane of 2026, the BBC reported. In its latest update, the US National Hurricane Center estimated Isaias is likely to reach hurricane strength by the start of Thursday and to strengthen further to category 2 by Friday morning.

Landfall is expected on the Gulf Coast, probably in Louisiana, Mississippi, Alabama or Florida, late on Friday or early on Saturday, according to the BBC. The US National Weather Service has issued Hurricane and Storm Surge Watches along the Gulf Coast. Florida Governor Ron DeSantis declared a state of emergency across 25 counties over concerns about potential impacts, the BBC reported.

Between 3 and 6in (75-150mm) of rain could fall across the Gulf Coast from south-east Louisiana to north-west Florida, the BBC reported, with a few places seeing up to 10in (250mm) and possible flash flooding, especially in urban areas. Parts of Mexico will feel the first impacts, with 4in (100mm) of rain possible around the Bay of Campeche and the Yucatan Peninsula, accompanied by strong winds, according to the BBC. The BBC reported that dangerous winds are anticipated and a storm surge could flood low-lying coastal areas.

Isaias is the ninth tropical storm of the Atlantic season but will be the first to become a hurricane, the BBC reported. The BBC said the storm will end a record-breakingly quiet Atlantic season so far, in which storm development was suppressed by the growing El Niño pattern. Forecasters in the US had predicted the 2026 hurricane season would be quieter than average, and so far this has come to pass, according to the BBC.

Isaias formed in an area with limited wind shear and very high sea temperatures, currently 30 or 31C, which the BBC said gave the storm the fuel it needed to grow. Forecasters expect it to encounter more wind shear as it moves northwards over the next few days, which should limit its intensification somewhat, the BBC reported.

The BBC reported that exact forecasts are likely to shift over the coming days. As the storm moves further inland and loses contact with its warm water fuel source it will weaken, but it is still expected to bring potentially disruptive wet weather for large areas of the south-east USA as far north as the Tennessee Valley and the Carolinas, according to the BBC.