Sam has weakened somewhat with max winds currently estimated at 110 knots as it moves northwestward (310 degrees) at 7 knots and is forecast to continue on this track for 2-3 days then turn more northward Thursday and Friday. Sam is forecast to move over warm ocean temperatures while it remains in an environment of low vertical wind shear through the next 4 days so further weakening is not expected during the next couple of days.
Heavy swell conditions will affect portions of the lesser Lesser Antilles including the Virgin Islands and north coast of Puerto Rico later this week.
Sam continues to look quite impressive on satellite images, with a 20-25 n mi wide eye surrounded by very deep convection and max winds about 125 knots with max significant wave heights to 45 feet (13.7 meters). The hurricane is moving a little faster toward the northwest, or at about 320/11 kt. During the next couple of days, a gradual turn toward the north is likely.
Sam should continue to move over waters of high oceanic heat content and within a low-shear atmospheric environment for the next 24 hours or so. Thus, it could still strengthen a little today and tonight. By 48 hours, decreasing SSTs and increasing shear should lead to a gradual weakening trend.
Swells generated by Sam will impact the northern Leeward Islands and the Greater Antilles, including Puerto Rico, during the next few days. Swells are expected to reach Bermuda and the Bahamas
by Friday, and then spread to the United States east coast by this
weekend.
