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Could Florence Rival or Surpass Hazel, Hugo in the Carolinas?

| September 9, 2018 @ 12:35 pm

Well, an anticipated El Nino hasn’t kicked in yet, and sea surface temperatures have warmed across much of the Atlantic. We are at the climatological peak of the Atlantic Hurricane Season, so guess what? We have three named storms marauding the basin on this September 9th. By the end of the coming work week, we will be dealing with a major hurricane threatening the U.S. East Coast and a hurricane moving into the Caribbean.

Your eyes are probably drawn to the area of disturbed weather over the western Caribbean Sea. That is a tropical wave interacting with a trough. Development is not expected, but it will be watched closely as it enters the Gulf of Mexico eventually.

FIRST, FLORENCE: Florence regained hurricane status this morning a little more than 1,500 miles east-southeast of Wilmington on the North Carolina Coast. This is about 600 miles northeast of the northern Leeward Islands and about 1,6000 miles east of Miami. The storm is moving west at 6 mph and is expected to take a west-northwesterly track around the southern periphery of a building high-pressure system over eastern Canada that will block Florence’s track out to sea. In the meantime, the system has good organization and is in an environment of light wind shear and increasingly warm water, which is a recipe for rapid intensification. Florence is forecast to become a major hurricane tomorrow afternoon, with winds of 115 mph.

By late Tuesday morning, it should have winds of 145 mph, and it should basically maintain that strength with the usual fluctuations until near the time of landfall which should come Thursday somewhere between North Carolina and northeastern Florida. There is such uncertainty because that is just the state of the science. The average NHC forecast error for the prediction of the center location is over 200 miles. That’s why Max Mayfield always said, “don’t focus on the skinny black line.” That average error could mean the center could be near Jacksonville, Florida, or near Cape Hatteras by late Thursday.

That, of course, means the differences in the impacts along the coast. But needless to say, wherever the storm comes ashore, the impacts will be tremendous, including devastating winds and very large storm surge. In addition, there are signs that Florence’s westward track could be blocked by building high pressure over the Ohio Valley about the time it makes landfall, which will mean slow movement about the time it makes landfall. This could lead to astronomical rainfall amounts across the Mid-Atlantic, which would be disastrous, especially given that the area is way above normal for rainfall this year already.

WHAT SAY THE MODELS? Always interesting to check in with the models. The spaghetti plot shows tracks from Savannah to Norfolk, with a concentration over North Carolina. The European deterministic output from last night showed landfall near Wilmington NC Thursday afternoon. But the Euro ensembles are scattered from Cape Hatteras to Savannah, with no real concentration. South Carolina seems to be a slight favorite. The new run of the GFS brings it right up to the North Carolina Outer Banks late Thursday and basically stalls it there into the weekend. That would be a disaster for the Outer Banks, Chesapeake Bay (including the Hamptons of Southeast Virginia) and the Delmarva where an extended period of surge could be devastating. The GFS ensembles seem to be more focused on the North Carolina coast, with some of its members keeping it just offshore of the Delmarva.

HISTORICAL STORMS: A category 4 Florence at landfall near Wilmington would make it the strongest hurricane since Hazel in 1954, which made landfall near the South Carolina/North Carolina border. Of course, Hazel is the storm of record for the North Carolina Coast, and the deadliest. It brought an 18-foot storm surge to the coast along with 150 mph winds. Much of eastern North Carolina suffered heavy wind damage. Up to 11 inches of rain fell. 1996’s Fran made landfall near Wilmington as a category 3 hurricane. It caused destructive flooding across much of eastern North Carolina and southwestern Virginia. Fran was preceded in the same year by Bertha, a category 3 hurricane that caused moderate damage along the coast. 1999’s category 2 Hurricane Floyd made landfall near Wilmington as well, but caused biblical flooding over eastern North Carolina. Finally, Isabel, the 2003 category 2 hurricane with the category 3 surge caused major damage along the Outer Banks, isolating communities for months.

THEN THERE’S HUGO: The South Carolina coast has been largely immune from direct landfalls from major hurricanes since 1916. With one exception, 1989’s Hurricane Hugo made landfall just east of Charleston on September 21, 1989 as a category 4 hurricane wind top wins of 155 mph and a central pressure of 934 millibars.

HAVING SAID ALL OF THAT: Florence could be the as strong or stronger than the previously strongest hurricane of record on the North Carolina or South Carolina coasts. This shows why residents along the coast from northeastern Florida through the Mid-Atlantic states need to pay close attention and start making preparations now since we are five days away from it happening. We will be following Florence’s every step all week.

IMPACT ON ALABAMA: Given its current forecast track, Florence should have little negative impact on Alabama’s weather.

ISSAC: Issac is a small tropical storm about 1,200 miles east of the Lesser Antilles this afternoon. It is in an environment favorable for strengthening and is forecast to be a hurricane, perhaps even a major hurricane, when it reaches the islands Thursday morning. It will encounter increasing shear over time and will weaken after it moves into the eastern Caribbean. It looks like it will eventually affect Nicaragua and Honduras eventually around the 19th of September.

HELENE: Tropical Storm Helene is in the far eastern Atlantic. It is expected to become a hurricane soon but should turn northward into a temporary weakness in the high-pressure ridge to the north.

Category: ALL POSTS, Tropical

About the Author ()

Bill Murray is the President of The Weather Factory. He is the site's official weather historian and a weekend forecaster. He also anchors the site's severe weather coverage. Bill Murray is the proud holder of National Weather Association Digital Seal #0001 @wxhistorian

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