Florence outer rain bands already reaching the Carolinas
LATEST FROM THE NATIONAL HURRICANE CENTER:
Florence is moving west-northwest at 13 mph with maximum sustained winds of 110 mph.
THE SCIENCE BEHIND FLORENCE:
Steering factors have shifted the Florence track slightly south. High pressure near Bermuda has Florence quickly moving west-northwest through Thursday. This high pressure will eventually collapse resulting in no steering currents for this hurricane, therefore, Florence is then forecast to stall out possibly on Thursday/Friday. This has raised a major concern with possible life-threatening flooding.
Another change in the forecast is the intensity upon landfall. Florence MAY make landfall as a category 1 or 2, BUT the coast of North and South Carolina may still experience major category 3 or 4 impacts. Here is why: as Florence loses steering currents, it stalls out. If Florence stalls over the Atlantic Ocean, it pulls up cold water from the bottom of the Atlantic which will allow the hurricane to weaken. This is called upwelling. As of Wednesday morning, Florence is forecast to stall over the Atlantic, but Florence is still 48 hours away from possible landfall, so if there is a slight change in steering currents, this would change.
It is important to stress THE MAJOR IMPACTS HAVE NOT CHANGED FOR THE CAROLINAS, therefore, do not focus too much on the intensity upon landfall.
After the Bermuda high pressure collapses and after possible stalling of Florence, a high pressure building over the Midwest late Friday could send it west/southwest. The latest ECMWF has it tracking along and down the South Carolina. coast. That is not a forecast, but is another possible scenario. Anyway you slice it, this will be a significant hit for the Carolinas.
TIMING AND IMPACTS:
Landfall time depends on steering currents and stalling. As of Thursday morning, there may be two landfalls. One in North Carolina and one in South Carolina. The first landfall will likely be late Thursday night/Friday morning.
Impacts will be significant across the Carolinas. Along the coast and far inland with the primary threat being catastrophic, life threatening flooding.
Storm Surge will be highest east of the center. As of Thursday morning, the highest surge looks to be on the southeastern coast of North Carolina. Possibly producing a surge as high as 7-13 feet. The northeastern coast of South Carolina will likely see a storm surge of 4-7 feet.
Rainfall will be the greatest threat with this hurricane as it is forecast to stall allowing for a constant flow of Atlantic moisture. Coastal flooding and inland flood are both major concerns. Some models are indicating 30+ inches of rain.
With any hurricane, there are strong winds. Hurricane force winds will be felt closest to the center with Tropical Storm force winds extending well inland.
ELSEWHERE IN THE TROPICS
Hurricane Helene is weakening and is now a category 1 hurricane moving north-northwest at 13 mph. Helene is forecast to be a "fish storm" and stay out in the Atlantic Ocean.
Isaac has been downgraded to a tropical storm as it tracks toward the Lesser Antilles. Most models are projecting a north turn after the Dominican Republic. Entrance into the Gulf of Mexico is not out of the question at this time. We will have a better grasp on this storm toward the beginning of next week. We will keep a close eye on it.
Also, an area of disorganized thunderstorms near the Yucatan has a high chance for development through the next few days. This will likely become our next Tropical Depression. Rain chances will likely increase across the western and northwestern Gulf coast.