Tropical Storm Grace intensified into the second hurricane of the 2021 Atlantic hurricane season Tuesday morning, and some additional intensification is likely before it makes landfall along the northern Yucatan Peninsula early Thursday morning. In addition, Tropical Storm Henri is close to becoming a hurricane, and models are suggesting that it may now pose a threat to New England by early next week.

As of 5:00 p.m. EDT Wednesday, Hurricane Grace was centered near 19.7°N 83.7°W, and was moving west-northwestward at about 16 mph. Maximum sustained winds were 70 knots (80 mph), with an estimated minimum pressure of 992 mb. After a period of intensification this morning, reconnaissance aircraft suggested that Grace’s intensity had begun to level off, likely as a result of dry air intrusion. Both NOAA and Air Force Hurricane Hunter Aircraft are scheduled to investigate Grace this evening, and they will be helpful to suggest if intensification has resumed. Grace should continue on its west-northwestward motion for the next day or so, before turning west-southwestward over the Bay of Campeche. Light to moderate shear of around 10-15 knots, as well as sea surface temperatures near 30°C (86°F), could allow some additional intensification of Grace tonight, but it appears unlikely Grace will be stronger than Category 1 intensity as it makes landfall in the Mexican State of Quintana Roo. The center of Grace should make landfall early Thursday morning, and land interaction with the Yucatan Peninsula should weaken the cyclone tomorrow to a tropical storm. The cyclone will be only inland for about 12 hours, and will emerge over the warm waters of the Bay of Campeche tomorrow evening. The environment is likely to remain conducive for strengthening in the Bay of Campeche, but it can take time for tropical cyclones to re-establish an inner core after crossing the Yucatan Peninsula, which suggests rapid intensification of Grace in the Gulf of Mexico is not particularly likely since it will likely run out of time before it can do so. Although the HWRF model makes Grace a major hurricane in the Bay of Campeche, this scenario seems unlikely due to the limited amount of time the cyclone will have over water. Regardless, Grace remains a serious threat to both the Yucatan Peninsula and mainland Mexico. A Hurricane Warning is currently in effect from the Yucatan Peninsula from Cancun to Punta Herrero. A Tropical Storm Warning remains in effect for the Cayman Islands as well as parts of the northern and western Yucatan Peninsula. The northern Yucatan Peninsula was hit by Hurricanes Gamma, Delta and Zeta last year all in the month of October, so this region has seen quite a bit of hurricane activity recently.

As of 5:00 p.m. ET Wednesday, Tropical Storm Henri was centered near 29.9°N 67.6°W, and was moving westward at about 9 mph. Maximum sustained winds were 60 knots (70 mph), with an estimated minimum pressure of 995 mb. Henri is very near hurricane strength, and without recon data in this storm, it’s possible the intensity could be a little higher. An Air Force Hurricane Hunter aircraft is scheduled to investigate Henri tomorrow afternoon, which will provide a better assessment of the cyclone’s intensity. Some northerly shear of around 20-25 knots may limit Henri from strengthening for the next day or so, but since the cyclone is already very close to hurricane intensity, it could become a hurricane as soon as tonight. On Friday, Henri should make a sharp turn to the north. After that time, the vertical shear is expected to decrease while the cyclone remains over warm waters, and Henri is likely to intensify into a hurricane then if it does not become one sooner. There has been a substantial westward shift in the model guidance today as Henri has gotten stronger than most models anticipated, and it now appears there is a chance that Henri could threaten New England early next week. No watches or warnings have been issued as of this time. Regardless, interests in New England as well as New Jersey and New York should closely monitor the progress of Henri.