HURRICANE FLORENCE TRACKING -- potentially the worst ever

[JimMIA]

I think it's helpful to separate this out from a couple of threads that are talking about members specific travel plans, because it makes it easier to collect the weather info in one place.

This Sunday morning, we are probably 4 1/2-5 days out from landfall, so it's too early to make any accurate predictions about where landfall will be. The best guess is somewhere on the North Carolina coast, but specific landfall information is pretty meaningless anyway.

A much more useful piece of information is the extent of tropical force winds (39 MPH). The furthest projection we have on those winds is for September 12 (2-2 1/2 days prior to landfall) and TS force winds are projected to occur across a 270 mile wide span ahead of the storm. That illustrates one of the most important facts about hurricanes. They are NOT pinpoint storms; they are VERY large zones of very bad weather and dangerous conditions.

So here's where we are right now. Hurricane Florence is currently a Category 1 hurricane located far out in the Atlantic Ocean, moving slowly west at 5 MPH. As the storm moves westward, two things will occur.

1. It will move into much warmer water than it's in now, and that will lead to rapid intensification. Between 8 PM tonight and 8 AM Tuesday (36 hours), Florence will intensify from a Category 1 to Category 4 hurricane with 140 MPH winds.
2. Florence will shift course from westerly to WNW and then NW. The timing and extent of that shift will determine where Florence comes ashore. The current track predicts landfall along the southern half of the NC coast, but I personally would be surprised if that doesn't move more northward over the next few days. We'll see.

Effects:

The effect of the storm in the immediate area will be wind damage, and much more important -- water damage from storm surge along the coast and flooding inland. Inland flooding could be really severe, because eastern NC is very low elevation topography. It is also possible that Florence will stall after moving inland, becoming a really bad rain event in an area that does not do well with heavy rain.

A much wider effect will be the impact on travel plans. On the chart below, you can see that by Wednesday night, tropical storm force winds are possible from roughly Daytona Beach, FL to NEW YORK CITY! That will affect the airlines and road/rail travel throughout that area.



I'll try to update this daily, and anyone else is welcome to jump in and contribute.

 

[goofy4tink]

Thanks....that will be very helpful.

 

[awfpack]

Thanks for that info. We are flying out of Greenville SC (GSP) Thur late afternoon on Southwest. I'm very curious as to what will happen and where.

 

[Ariel1014]

Thank you for this! We fly our of RI Saturday morning direct flight. Here's hoping....

 

[JimMIA]

This is a SOUTHWEST AIRLINES ALERT -- Thanks to Shelly!

ALERT ISSUED
https://www.southwest.com/html/advisories/swa_travel_advisory_2018891536512869640.html

 

[Jillpie]

thanks Jim, most helpful, I will be checking this very closely this week!

 

[goofy4tink]

Thank you for this! We fly our of RI Saturday morning direct flight. Here's hoping....

I'm flying out of Boston at 8:30 Sat morning...I think it's going to be a bumpy ride!!!! If not bumpy, then long!! They'll go way west to avoid the storm.

 

[Ariel1014]

I'm flying out of Boston at 8:30 Sat morning...I think it's going to be a bumpy ride!!!! If not bumpy, then long!! They'll go way west to avoid the storm.

That's what I am hoping, that they re-route to go around. We leave at 8:30am as well!

 

[JimMIA]

Here are the 11 AM Monday track and TS force wind maps. There is a lot going on beneath the surface, but little change in the overall guidance at this point, so the maps look pretty familiar.





The current track predicts landfall somewhere along the southern NC coast shortly after midnight Thurs/Fri as a Category 4 hurricane (135+ winds).

However, you can't take either the predicted landfall or timing seriously at this point. At 4-5 days out, landfall could actually occur 180 miles or more from where they are predicting now.

The computer models these tracks are based on have actually diverged a bit overnight -- one moving more south, others moving more north. By Wednesday, we should have a much better idea where Florence will go.

From the TS force wind map, you can see that TS force winds are expected to reach out more than 24 hours in advance of the eye of the hurricane and are currently expected to possibly affect almost all of Georgia all the way through New Jersey. That cone of TS force winds will narrow some as the storm gets closer, but those winds will still cover a very wide area.

 

[JimMIA]

Brief update: At Noon Monday, the National Hurricane Service upgraded Hurricane Florence to a Category 4 hurricane with sustained winds of 130 MPH. The upgrade is based on a Hurricane Hunter flight into the storm this morning.

The storm has also accelerated to 13 MPH motion in a westerly direction. It was last located 1,230 miles ESE of Cape Fear, NC -- so it's still a long way off.

The overall track of the storm has not changed from the 11 AM advisory info above.

 

[KPeterso]

Thanks for this thread. Flying in on Saturday AM from the west coast, so thinking my flight itself should be ok. Although, the plane for this flight the last few weeks has been coming from Atlanta before going to MCO, so we shall see! Will be watching this thread for information!

 

[JimMIA]

I'm not going to post the maps this evening because they really haven't changed much. Florence continues to intensify and is moving into even warmer sea temperatures, so that will continue.

At the 5 PM advisory, Florence had sustained winds of almost 140 MPH, with gusts to 167 MPH. The storm was moving WNW at 13 MPH and was approximately 1,170 miles ESE of Cape Fear, NC. No watches or warnings issued yet.

If this storm continues on its present course, and nothing happens to weaken it, it is going to be a potentially catastrophic event. Anybody on the south Atlantic seaboard should watch the advisories closely and follow the advice of local authorities. Evacuations may be ordered several days ahead of anticipated landfall, because strong effects of this storm will hit long before landfall.

 

[siggy59]

Thank you for this! We fly our of RI Saturday morning direct flight. Here's hoping....

hey we are flying out of ri on saturday morning as well but we are on the 11 am flight

 

[fla4fun]

If this storm continues on its present course, and nothing happens to weaken it, it is going to be a potentially catastrophic event. Anybody on the south Atlantic seaboard should watch the advisories closely and follow the advice of local authorities. Evacuations may be ordered several days ahead of anticipated landfall, because strong effects of this storm will hit long before landfall.

Please heed the evacuation orders. After riding out Irma last year in the basement of our home (the eye went right over us) I am seriously considering future evacuation for anything above a cat two, and I will never ever have a mandatory evacuation order where I live. Riding out a storm is terrifying, especially when it comes at night like Irma did and like it appears Florence will as well, and this one is predicted to just barely make landfall and then just sit for a day or more. There is nothing more important than your safety. Nothing.

 

[JimMIA]

Here is the 11 AM TUESDAY tracking map:


At 11 AM this morning, Florence was located about 900 miles ESE of Cape Fear, NC and moving WNW at about 14 MPH. Florence is experiencing fluctuations in intensity due to eyewall regeneration, as is very common with hurricanes of this intensity. However, she continues as a strong Category 4 storm with sustained winds of more than 130 MPH and gusts to 160.

Florence is expected to continue on this track, slowing somewhat as she approaches the coastline. Florence is expected make landfall early Friday morning. There is some uncertainty in some of the models around the time of projected landfall and the system could shift a bit to the south prior or at landfall.

Although wind speed gets all the attention, water is a bigger threat to life and property, and Florence carries two huge water threats.

The first is storm surge in coastal areas -- which is the elevated sea level pushed ahead of the approaching storm. Storm surges strike well in advance of the eye actually making landfall. I read one discussion yesterday where the scientists were saying the Florence may produce a record storm surge in the range of 15-20 feet. In the coastal Carolinas, with their low elevation, storm surge could cause catastrophic effects.

The second major water threat is inland flooding from heavy accumulations of rain. On the map above, you can see that Florence is expected to weaken to a Category 3 storm, then Tropical Storm, and finally Tropical Depression after landfall. However, that is just diminishing winds. The system will still continue heavy rainfall and is projected to remain within North Carolina for three days or more, although heavy rain will also probably affect SC, and parts of VA and GA.

There will be a strong threat of flash flooding in the higher elevations of the Carolinas and Virginia, and that could extend to the western side of the Great Smoky Mountains in Tennesee as well. And that threat may last several days.

 

[WelshDH@98CPAlum]

Thank you! Some of our group are flying Thur from Milwaukee to Orlando...

 

[JimMIA]

Here's an NHC map showing the anticipated accumulated rainfall expected from Hurricane Florence.



As you can see, essentially all of North Carolina and Virginia can expect a lot of rain. 4 inches of rain is a LOT and it's a lot more than these areas usually get in one big dump. Everything on the map inside the dark green band is greater than 4".

Large areas are going to get more than 10 inches of rain, and some are going to get up to 30 inches.

Also keep in mind that the western area of both states is mountainous. Mountain ranges act as collection devices with rainwater flowing down into small streams, merging into bigger streams, and merging further into flash floods. Even though the rainfall rates will be less, you can see the same flooding effect likely in West Virginia and the mountainous areas of Pennsylvania.

 

[Betty Rohrer]

Here's an NHC map showing the anticipated accumulated rainfall expected from Hurricane Florence.

View attachment 350237

As you can see, essentially all of North Carolina and Virginia can expect a lot of rain. 4 inches of rain is a LOT and it's a lot more than these areas usually get in one big dump. Everything on the map inside the dark green band is greater than 4".

Large areas are going to get more than 10 inches of rain, and some are going to get up to 30 inches.

Also keep in mind that the western area of both states is mountainous. Mountain ranges act as collection devices with rainwater flowing down into small streams, merging into bigger streams, and merging further into flash floods. Even though the rainfall rates will be less, you can see the same flooding effect likely in West Virginia and the mountainous areas of Pennsylvania.

based on last month's rain put Lancaster and Harrisburg in areas could flood if we get more rain. small stream behind me is back in banks but still very high from August 31 rain

 

[UncleMike101]

Our Daughter and Family just moved from Wilmington NC last year and we're thankful they did or all of us would be heading West right now.
As it is we're in an area that only expects 30 MPH winds and approx 6 inches of rain so this shouldn't be any worse than a really good day long thunderstorm at home.

 

[Shelly F - Ohio]

Our Daughter and Family just moved from Wilmington NC last year and we're thankful they did or all of us would be heading West right now.
As it is we're in an area that only expects 30 MPH winds and approx 6 inches of rain so this shouldn't be any worse than a really good day long thunderstorm at home.

. I see it was just updated and it looks like it will be coming further in land than what was first reported. The storm will be slow moving as well. Could be a big factor in those driving down as they will have to drive even further west to go around the storm in order to get to WDW.
SWA has cancelled flights out of RDU for Thru and Fri.