Subtropical Storm Nicole developed Monday morning in the Atlantic and will bring tropical-storm-force winds, heavy rain, and coastal impacts to the Palmetto State later this week.
Tropical storm warnings have been issued from the mouth of the South Santee River to the South Carolina-Georgia border. These warnings are in effect for coastal waters, however, a late-week visit from Nicole could bring an expansion of watches and warnings to places like Charleston and Beaufort in the coming days.
Current observations from Subtropical Storm Nicole indicate sustained winds of 45 miles per hour as it continues pushing toward the northwest. As Nicole encounters a strong ridge of high pressure off the Northeast coast Tuesday, it will get pushed southwest toward the east coast of Florida. From there, questions remain as to where Nicole will go. Current model guidance suggests an incoming trough of low pressure will essentially scoop Nicole up and move it northeastward. This will provide a close call for the Palmetto State, especially for coastal areas. The official forecast from the National Hurricane Center depicts nearly the entire state in the "cone of uncertainty," which means tropical-storm-force winds and rounds of heavy rain will be possible for the entire state through the end of the week.
Sustained winds of between 39 and 73 miles per hour will inch closer to coastal areas Thursday morning. The long fetch of onshore winds through the latter half of the week will result in water piling along the coast of South Carolina Friday and Saturday, aided in part by those strong easterly winds. The latest advisory has tropical-storm-force winds overspreading the Midlands and Pee Dee by Friday morning before possibly moving toward the Upstate through Friday.
Rain will likely be heavy at times as Nicole moves through the state ahead of an approaching cold front, further squeezing the atmosphere of its moisture. Rainfall of several inches could fall and it could result in localized flash flooding, noted by the Weather Prediction Center's Day 5 Excessive Rainfall Outlook. Along the coast, 2 to 4 inches of rain are possible, with the rest of the state getting an inch or two. While those rainfall amounts may not seem overly problematic, if a few inches fall within a short time, it can lead to issues with localized flash flooding.
Another aspect to keep in mind with landfalling tropical systems is the risk of a few spin-up tornadoes. Tropical tornadoes tend to be short-lived and weak, but they can develop with little to no advanced notice. Residents are encouraged to have multiple ways to receive weather alerts in the days ahead to help them stay prepared and ahead of warnings that may get issued.
Nicole is still several days from making landfall along the east coast of Florida, so potential impacts to South Carolina are at least four days out. Keep a close eye on the forecast in the days to come, as the track of Nicole will be fine-tuned over the next 24 to 48 hours.