This latest storm Matthew seems to be following the Atlantic coastline. It’s travelled northwest, then slowly curved toward the northeast.
The questions: is there a general correlation between hurricane tracks along the Atlantic and the coastline of Florida, Georgia, and the Carolinas? If there is a correlation, is there any causation between them?
That is, is the path of the hurricane deflected in some part by having water to the east and land to the west? And/or, has the path of many hurricanes eroded the land so that the coastline somewhat follows the typical track?
Hurricanes tend to follow this track whether over land or water. Somewhere around the top of Florida, at that latitude, it appears Coriolis force or the jet stream or some weather pattern causes storms to turn northeast. The shape of the coast is just a coincidence, since the very deep continental shelf follows the same contour.
For a simple comparison, here’s the historical chart for Cat 3+ October hurricanes that something-something near Matthew. I think, maybe, that star point off FL is the “near Matthew” reference point. Not sure. (This might also get updated so the comparators might change later.)
Anyway only 1 or 2 seems to have run up the coastline. (I see 2 lines going in, 1 coming out. Maybe one of them dissipated. There’s another pair like that coming in from the lower left.)
The scatter does seem odd. I’m more used to the classic “boomerang” shape for many tracks. Drift in from the east, turn N, then NE. Maybe staying the open ocean or crossing onto land before heading to the NE. Carribean/Gulf 'canes do little, if any eastward journey before heading NE. Unless they are south enough then Mexico gets all the fun. (But the remnants often still end up in the SW US and then going NE.)
During a lot of most summers, there’s a “Bermuda high” hanging around in the Atlantic. This stops a lot of the usual W-E weather systems. Hurricanes can track around the western edge of this. Depending on its position and strength, a track can be inland, offshore, etc. (The Wikipedia page on this is crappy. It shows the winter position only.)
The northeastern part of Florida rarely has hurricanes, along with the southeastern part of Georgia, because of their geographical situation. Most hurricanes from Africa go south of the Caribbean islands into the Gulf of Mexico or north of the Caribbean islands up the east coast or back into the Atlantic. That specific enclave is normally immune from hurricanes. Matthew went south of the Caribbeans and then swept north up through the windward channel. This was Jacksonville’s first major hurricane.
The large scale air flow gives us Easterly flow between the Equator and around 25º latitude (a.k.a. the trade winds). From 25º up to about 70º this large scale flow provides Westerly winds.
Let’s start our tropical storm in the Equatorial Atlantic. The Easterlies push the storm to the west and if there’s no push to the north, the storm tracks straight across and slams into Central America. Now if there is a push to the north, the storm will leave these Easterlies and get caught up in the Westerly flow pushing it back to the east. This is what gives us a typical re-curved storm track.
So, to the OP … there’s nothing special about Matthews track right off the USA’s coast. Shift the track 200 miles either way and we’d see the same thing. Simple coincidence that the storm tracked just off-shore like it is. The land doesn’t really effect the track, however the land has a direct impact on the strength of the storm. Last I checked, Matthew has begun to entrain dry air and is starting to dissipate. That is caused by the land interaction.
It may recurve back to the southwest because tropical cyclones do not necessarily follow the prevailing wind pattern. They are not associated with any frontal system. Once they do associate with a front they lose their tropical characteristics, which, in particular, is a hot core from warm waters, which give them their source of energy. Many factors determine their paths, which makes their paths so hard to predict. The Bermuda high was blocking Matthew’s path to the east. It follows the path of least resistance. It was hoped it would be picked up by a cold front from the west to kick it out to sea, but the front did not arrive in time. Apparently (and I do not know – just a guess) the High will prevent it from moving further east and will find a steering current from another tropical cyclone also in the Atlantic, kicking it back to Florida.
I’m at the Atlanta airport and there is a slight backup on departures and arrivals maybe 30 minutes or so. And if you look off to the east ( I’m at terminal F) you can see a storm off to the east… The approach and landing was a bit bumpy.
This is a very help reply; I hadn’t thought to look at the continental shelf.
I found this webpage help, Virginia and the Outer Continental Shelf . However, it doesn’t clear up the issue for me. The Hatteras slope (see the sixth picture) does follow the modern coastline, but the continental slope does not. That is, it looks like the coastline, both modern and ancient (as indicated by the Hatteras slope) is significantly more eroded away from the continental slope than it is further north. I don’t think it’s possible to rule out hurricanes as a contributing factor.
There’s nothing intrinsic to Jacksonville’s location that prevents a major hurricane from making landfall there. At best, the continental shelf has a trivial effect on the track of hurricanes. There is evidence that the depth of warm ocean water effects the intensity of hurricanes. However, from this we can only infer that landfalling Category 5 hurricanes are of a much lower probability at Jacksonville, under no circumstances does this mean Category 5 hurricanes cannot make landfall at Jacksonville. Just because it’s never happened in recorded history doesn’t mean it can’t, weather records don’t go back far enough.