Isaias tried to reorganize over the warm water of the Gulf Stream overnight, but the hostile upper winds and dry air won the battle. The maximum intensity of the winds has come down, but it remains a well-organized storm that can do damage if the core comes over the coast. It has been wobbling, but it is pretty much on track.
On the current track, the storm will increasingly impact the Florida coast from the Palm Beaches to the north today. The center of the Isaias is forecast to track over or near the coastline all the way from Palm Beach county to north-central Florida.
Damaging winds, flooding rain, and dangerous storm surge are expected in some areas. Depending on the orientation of a particular segment of the coastline, the ocean water could be pushed 2 to 4 feet above normal high tide, with waves on top of that along the central and northern Florida east coast. Storm surge occurs when the wind is blowing onshore, so that will be before the center of the storm arrives.
A difference in the track of Isaias’s center of circulation will make a significant difference in the amount of wind, rain, and storm surge at the coast since the bad weather doesn’t extend very far west of the center. The critical deviation required to dramatically change the impacts is unforecastable, so residents need to be prepared for the possibility of direct effects.
The only leftover impact of Isaias in Miami-Dade and Broward other than an occasional gust of wind is extremely moist tropical air. Heavy moisture and showers will linger early in the day, and when thunderstorms develop later, they could be quite heavy. Ironically, they will likely be heavier and gustier than almost anything we saw with Isaias.
Tides will run a couple of feet above normal at the coast, especially in Broward, but will recede as Isaias moves north.
Farther up the coast, the impact on the Carolinas, the Mid Atlantic, and the Northeast is a different concern. Not only will there be coastal impacts, but very heavy rain is expected inland as well.
Unlike its trek near Florida where the worst weather was on the east side of the circulation, the jet stream will likely enhance the heavy rain on the west side of the track as Isaias speeds north. Flooding well inland away from the coast is possible from the Carolinas to the Northeast.
Residents from Palm Beach County in Florida all the way to New England should stay in close touch with local forecasts. Things are expected to rapidly evolve. The National Weather Service and the National Hurricane Center will soon be issuing alerts for dangerous conditions expected along the coast and inland.
Elsewhere in the Atlantic, a disorganized disturbance northeast of the Caribbean islands is moving north well east of the U.S. East Coast. It is likely to stay offshore.
A weak tropical depression near Africa has dissipated. Nothing else appears to be in the offing for the next several days.