As we climb over the climatological peak of hurricane season, the tropical Atlantic remains pretty active with a couple named storms and two tropical waves. Hurricane Lee is holding on to major hurricane (Category 3 or higher) status while Margot became the latest hurricane Monday. A tropical wave off the coast of Africa will have to be watched for possible development over the next week. Thankfully, for us here in Louisiana, there are no tropical threats expected in the Gulf of Mexico over the next 7 days.
Hurricane Lee is a category 3 storm with max winds at 115 mph and a minimum pressure of 948 mb, per the 4 PM CDT advisory. This storm was once a very powerful category 5, but since then, it has experienced several replacement cycles (ERCs). These ERC processes typically cause short-term weakening as the main eyewall weakens and decays as a new outer eyewall develops. Lee is in the middle of an ERC Monday evening and its overall strength will fluctuate over the next couple days.
The forecast track continues a slow west-northwestward motion well to the north of Hispaniola and Puerto Rico as it follows steering currents from high pressure to its northeast. By mid-week, Lee will be influence by an upper-level trough over the Eastern U.S. that will cause the storm to turn to the north and speed up. As it moves north, the storm’s strength will weaken, but the wind field will begin to expand.
As Lee tracks north paralleling the East Coast, it will cause higher seas and dangerous rip currents along the coast. Some impacts are possible to the Northeast U.S. and the Canadian Maritimes towards the end of the week, but it is too soon to tell the exact impacts. Interests should continue to monitor the forecast.
Margot became a hurricane on Monday and currently has max sustained winds at 75 mph, per the 4 PM CDT advisory. It is forecast to strengthen to a category 2 storm over the next couple days as it races to the north. By the end of the week, steering currents will weaken allowing for Margot to slow down and possibly stall out. Thankfully, all this will occur over the open Atlantic and this storm will have no land impacts.
African Easterly Waves
Southwest of the Cabo Verde Island is Invest 97L, a broad area of lower pressure with disorganized thunderstorms. It is unlikely for development of this system before a tropical wave behind it merges with it. The tropical wave just off the coast of Africa, Invest 98L, has a 70-percent chance of development over the next 7 days. This wave will move generally west-northwest over the Central Atlantic and environmental conditions look to be favorable for some development of this wave. A tropical depression could possibly form by this weekend.