A significant change in the weather pattern that is steering Dorian is increasing the risk of at least some effects from the powerful hurricane in South Carolina later next week.
The storm continues as a powerful category 4 hurricane. Seasonably warm ocean temperatures and light wind shear — both of which are normally needed for intense hurricanes — are expected to fuel the storm for several more days.
A ridge of high pressure that is steering the Dorian is forecast to keep pushing it westward this weekend toward the northwestern Bahamas. The ridge; however, is now forecast to be much weaker by Monday, which will cause it to slow or stall just offshore of Florida Monday. It is still close enough to the Sunshine state to prompt Tropical Storm Watches for portions of its east coast. A turn toward the north is likely Tuesday and Wednesday.
Forecasters say it’s too soon to know for sure how the conditions may be in South Carolina. If Dorian reaches the state, high winds, heavy rain, and surge may arrive late Wednesday or Thursday, especially closer to the coast. The latest National Hurricane Center forecast has a 60% chance of tropical storm force winds reaching the entire coast of South Carolina. These winds are most likely to arrive near Hilton Head first as early as Tuesday morning, but are more likely on Wednesday. They may not reach Myrtle Beach until Tuesday night at the earliest, but more likely on Wednesday afternoon. NOAA's Weather Prediction Center forecasts 5 to 10 inches of rain near the coast, assuming Dorian stays with the current track.
Regardless of the exact track of the hurricane, coastal flooding is expected. The National Weather Service in Charleston has issued Coastal Flood Warnings from Hilton Head to the Charleston areas. The National Weather Service in Wilmington, NC has Coastal Flood Advisories in effect from the Georgetown to Myrtle Beach areas. Tidal departures of around 1 foot above normal are anticipated in these areas because of high astronomical tides.