Due to dry mid-level air and an increase in wind shear, as predicted by much of the model guidance, Hurricane Isaias weakened to a high-end tropical storm on Saturday afternoon. However, Isaias is still likely to be a strong tropical storm or minimal hurricane when it makes its closest approach to southeastern Florida on Sunday, and is likely to still be a strong tropical storm

As of 5:00 p.m. EDT Saturday, Tropical Storm Isaias was centered near 25.1°N 78.7°W, and was moving northwestward at about 10 mph. Maximum sustained winds were 60 knots (70 mph), with an estimated minimum pressure of 993 mb. Isaias recently passed close to Andros Island in the Bahamas, and for a while today, the low-level circulation of Isaias was almost completely exposed. Despite the disorganized appearance, reconnaissance aircraft data confirm Isaias still has a vigorous circulation with winds near 70 mph. During the last few hours, though, convection has redeveloped north of the center, and it remains a distinct possibility Isaias could briefly reattain hurricane strength overnight or on Sunday morning while it turns towards the north. Isaias’ center is likely going to pass very close to southeastern Florida late Sunday morning, and a landfall remains possible – possibly as a minimal hurricane. If Isaias does make landfall in southeastern Florida, its center is expected to quickly reemerge over the western Atlantic as the storm turns to the north. After that time, the model guidance is in good agreement that Isaias will make landfall somewhere near the North Carolina-South Carolina line early Tuesday morning, most likely as a tropical storm.

Because of the possibility for Isaias to restrengthen to a hurricane, Hurricane Warnings remain in effect from Boca Raton to the Volusia-Flagler County Line in Florida. A Hurricane Warning remains in effect for the Northwestern Bahamas, though this is likely going to be canceled soon. A Storm Surge Watch is currently in effect from Jupiter Inlet to Ponte Vedra Beach, Florida. A Tropical Storm Warning remains in effect from North of Ocean Reef to south of Boca Raton, Florida, Lake Okeechobee, and from the Volusia-Flagler County Line to Ponte Vedra Beach, Florida. A Tropical Storm Watch has been extended from the north edge of the Tropical Storm Warning area to the South Santee River, South Carolina. Isaias’ maximum storm surge is expected to be around 2-4 feet in the Storm Surge Watch areas. Rainfall totals are expected to be relatively moderate outside the Bahamas (where 4-8 inches are expected), with maximum totals of 2-5 inches along the southeastern United States coast. Significant wind damage appears unlikely, due to Isaias’ current lack of an inner core.