It is late August, and the already-active Atlantic hurricane season is quickly ramping up. Tropical Storm Marco became a hurricane over the eastern Gulf of Mexico for a brief time earlier today, but has since weakened to a tropical storm as it enters an environment of strong wind shear. Marco is expected to make landfall in eastern Louisiana on Monday evening, though it is unclear how much additional weakening will occur. Tropical Storm Laura has managed to maintain intact after crossing the mountainous terrain of Hispaniola. Laura is not likely to change much in intensity for the next day or so as it passes near Cuba, but is expected to enter a very favorable environment for intensification when it reaches the eastern Gulf of Mexico on Tuesday.

As of 11:00 pm. EDT Sunday, Tropical Storm Marco was centered near 26.8°N 87.6°W, and was moving north-northwestward at about 12 mph. Early on Sunday afternoon, Marco briefly intensified into the third hurricane of the 2020 Atlantic hurricane season. The average third Atlantic hurricane forms around September 9. Since that time, Marco has weakened due to strong southwesterly shear. Marco’s center is expected to move ashore over southeastern Louisiana on Monday evening as it turns to the west. Additional weakening is possible before landfall, and the global and hurricane models indicate that Marco’s low-level circulation is likely to become completely exposed around the time Marco’s center reaches the coast. A Hurricane Warning remains in effect from Morgan City, Louisiana to the Mouth of the Pearl River, though the shear suggests it is unlikely Marco will reattain hurricane strength before landfall.

As of 11:00 p.m. EDT Sunday, Tropical Storm Laura was centered near 20.1°N 76.6°W, and was moving west-northwestward at 21 mph. Maximum sustained winds were 55 knots (65 mph), with an estimated minimum pressure of 1000 mb. Laura has intensified slightly today as it moves over eastern Cuba. Although Laura’s winds have increased, earlier recon aircraft data suggests that Laura still lacks an inner core. Interaction with Cuba should limit intensification for the next 24 hours or so, unless the circulation emerges over water south of Cuba. On Tuesday, Laura’s center should emerge over the warm waters of the Gulf of Mexico, and Laura is expected to enter a low-shear environment. Laura is likely to intensify into a hurricane over the southeastern Gulf of Mexico by Tuesday morning and make landfall somewhere between eastern Texas and eastern Louisiana on Wednesday night. Although the official National Hurricane Center (NHC) intensity forecast predicts Laura will be a Category 2 hurricane at landfall, it is quite possible Laura could be stronger than that if rapid intensification occurs over the Gulf of Mexico. A Tropical Storm Warning is in effect for Little Cayman, Cayman Brac, the entire coastline of Cuba, and Dry Tortugas. A Tropical Storm Watch is also in effect for the Florida Keys.

The 2020 Atlantic hurricane season continues to produce named storms at a record pace. So far, 13 named storms have developed before September, the first such occurrence on record. The most active part of the season climatologically is only just beginning.