The ninth tropical storm of the 2021 Atlantic hurricane season, Tropical Storm Ida, was named Thursday evening over the northwestern Caribbean Sea. Ida has a very favorable environment for significant intensification over the next several days. The global model consensus indicates that Ida is likely to become a powerful hurricane over the central Gulf of Mexico, with significant deepening likely up until around the time of landfall. In addition to Ida, both Invests 97L and 98L have potential to develop into tropical cyclones, but do not appear to be imminent land threats.

As of 5:20 p.m. EDT Thursday, Tropical Storm Ida was centered near 18.0°N 79.8°W, and was moving northwestward at about 14 mph. Maximum sustained winds were 35 knots (40 mph), with an estimated minimum pressure of 1006 mb. Satellite intensity estimates are near tropical storm strength, and the Air Force Hurricane Hunter aircraft has just found flight-level winds that support tropical storm intensity. Ida has a very favorable environment ahead of it, and intensification appears likely. For the next 18-24 hours or so, Ida may struggle to intensify a bit due to its lack of an inner core as well as moderate southerly shear. However, it is not likely going to be enough to prevent intensification, and sea surface temperatures are expected to increase to around 30°C (86°F) by tomorrow afternoon as the cyclone nears western Cuba. The center of the cyclone should pass very close to the Cayman Islands in about 12 hours or so, and a Tropical Storm Warning has been issued for these islands. A Tropical Storm Warning has also been issued for the coastline of western Cuba. Although some slight weakening may occur while Ida’s circulation moves over Cuba, the terrain of western Cuba is not very mountainous and is not likely to disrupt the cyclone very much. After that time, Ida will enter a very favorable environment for intensification as it passes over a warm eddy, with wind shear less than 15 knots, sea surface temperatures an extremely warm 31-32°C (87.8-89.6°F), and 700-500 mb relative humidity values near 70 percent. This is a near ideal environment for rapid intensification, and the National Hurricane Center intensity forecast calls for Nine to become a high-end Category 2 hurricane. Considering how favorable the environment is, I’d be somewhat shocked if Ida did not at least reach Category 3 strength. Interests along the Northern Gulf coast from eastern Texas to the western Florida Panhandle should have a hurricane plan in place and be prepared to evacuate if necessary. The expected timeframe for a potential Louisiana landfall is likely between Sunday afternoon and evening. Late August has produced some notorious very intense Gulf of Mexico hurricanes, and residents along the northern Gulf Coast should be ready.

In addition to TS Ida, both Invest 97L and 98L have a high chance of development over the next 5 days. The NHC gives 97L, an area of disturbed weather over the central Atlantic, a 50 percent chance of development within 48 hours and a 70 percent chance within five days. Model support for 97L has decreased from 2-3 days ago, but it still appears possible that at least a weak tropical cyclone may develop. 97L does not appear to pose any threat to land, except for potentially the Azores if it develops. In addition to Invest 97L is 98L, which has become better organized today. The NHC gives 98L a 60 percent chance of development within 48 hours, and a 70 percent chance within five days. Much of the global model guidance indicates that 98L could become a tropical depression as soon as tomorrow, and this appears plausible. 98L will likely turn north well east of the Lesser Antilles, and will likely not pose a threat to land. The next two names on the Atlantic hurricane naming list are Julian and Kate.