ATL: HELENE - Post-Tropical - Discussion

[HurricaneBelle]

The issue is that after 72 hours they forecast in 24-hour increments instead of 12, so we get this:

72H 26/1200Z 27.1N 85.1W 95 KT 110 MPH
96H 27/1200Z 34.0N 83.0W 35 KT 40 MPH...INLAND

which means the storm could be stronger after 72 hours but before it makes landfall and that's not captured by this. When the 84-hour forecasted position is at or near forecasted landfall they should include that as well.

[Chemmers]

Looks like a CAT2 according to latest guidance from NHC. Nothing more than a Francine type of hurricane. But prepare for 1 category higher as typical.

I would take that cat 2 with a pinch of salt. most off the models are predicting 4 to 5, take care and stay safe everyone

[wx98]

Looks like a CAT2 according to latest guidance from NHC. Nothing more than a Francine type of hurricane. But prepare for 1 category higher as typical.

This has the potential to be way more than “a Francine type of hurricane.” Probably not the right comment for the situation here.

[3090]

Looks like a CAT2 according to latest guidance from NHC. Nothing more than a Francine type of hurricane. But prepare for 1 category higher as typical.

I would take that cat 2 with a pinch of salt. most off the models are predicting 4 to 5, take care and stay safe everyone

OK follow the models then.

[Pipelines182]

This storm looks like it will track near me (ATL). I think the ceiling is up to around a High cat 4 with this systems. All depends on how fast it gets together.

The ceiling is a cat 5, I'm not sure why so many people on here are so scared to say "Cat 5". It's unlikely, but certainly within the ceiling for this storm. The HWRF has nine going all the way down to 926mb and it is the best intensity model for RI, granted it also has a tendency to overforecast RI probability but it's a good model to judge where the ceiling is.

[wx98]

Looks like a CAT2 according to latest guidance from NHC. Nothing more than a Francine type of hurricane. But prepare for 1 category higher as typical.

We too early to determine the ultimate CAT status at landfall.

Not speculating. I am going only bY OFFICIAL NHC forecast. Anything lower or higher is highly speculative. There is a lot of times too much hysteria by the non professionals.

I am sure there will be updates up/down in forecast intensity as it evolves like always. Stay the course. Be vigilant. And pay sttention to the NHC OFFICIAL products issued.

I think you are misunderstanding the NHC forecast process and trying to use it as justification for insinuating that this storm won’t get as strong as most think. The intensity forecast will only go up with time.

[ScottNAtlanta]

Update from Accuweather calling for a major hurricane


Link: https://youtube.com/watch?v=ElXlSm1OkHo
BAM Weather calling for a cat 4


Link: https://youtube.com/watch?v=stzFUGLqapU

[Pipelines182]

We too early to determine the ultimate CAT status at landfall.

Not speculating. I am going only bY OFFICIAL NHC forecast. Anything lower or higher is highly speculative. There is a lot of times too much hysteria by the non professionals.

I am sure there will be updates up/down in forecast intensity as it evolves like always. Stay the course. Be vigilant. And pay sttention to the NHC OFFICIAL products issued.

I think you are misunderstanding the NHC forecast process and trying to use it as justification for insinuating that this storm won’t get as strong as most think. The intensity forecast will only go up with time.

He's a great example of why I believe the NHC needs to change their NHC intensity forecast products. I ran into it with Michael, so many people only see that one number and say "that's the forecast!" when in reality the forecast is for a wide intensity range, most people just don't read the discussion.

[psyclone]

The radii of gale and storm force winds may ultimately prove more important than absolute peak intensity as this system is moving toward an area insanely vulnerable to surge. Steve Lyons on TWC used to say that Apalachee bay is the most surge prone area in the entire Atlantic basin. I believe it. Another high water mark at St Marks looks like a given if the center moves near or west of there. The surge risk in the nature coast and down the west coast will be highly dependent on how large and how close the storm tracks to the coast but it looks to be substantial and worthy of evacuations...

[mpic]

I really really hate the way the NHC issues these intensity forecasts. I think their estimate is fine, but they really need to do a better job of broadcasting the ceiling on this storm is significantly higher than 95kt. Most people don't read anymore except for headlines, all they're going to see is "forecast to make landfall as a cat 2". When in reality they need to be seeing "forecast to make landfall anywhere from Cat 2 - 4".

https://www.facebook.com/share/v/xjURMrYiiU98U6is/?mibextid=oFDknk
Dr.Rhome just did a Facebook live and I was really impressed with it. He emphasized really well the importance of not depending on the cone for intensity and suggested the real possibility of a Cat 3.

[TomballEd]

We too early to determine the ultimate CAT status at landfall.

Not speculating. I am going only bY OFFICIAL NHC forecast. Anything lower or higher is highly speculative. There is a lot of times too much hysteria by the non professionals.

I am sure there will be updates up/down in forecast intensity as it evolves like always. Stay the course. Be vigilant. And pay sttention to the NHC OFFICIAL products issued.

I think you are misunderstanding the NHC forecast process and trying to use it as justification for insinuating that this storm won’t get as strong as most think. The intensity forecast will only go up with time.

NHC discussion says Cat 2 may be conservative. Or the storm could be stronger, and it is almost to Cat 3 strength on the current forecast.

[Pipelines182]

The radii of gale and storm force winds may ultimately prove more important than absolute peak intensity as this system is moving toward an area insanely vulnerable to surge. Steve Lyons on TWC used to say that Apalachee bay is the most surge prone area in the entire Atlantic basin. I believe it. Another high water mark at St Marks looks like a given if the center moves near or west of there. The surge risk in the nature coast and down the west coast will be highly dependent on how large and how close the storm tracks to the coast but it looks to be substantial and worthy of evacuations...

I would agree with that, but it's also one the least populated part of the Florida coastline, it's all mangroves there. Hurricanes also seem to make landfall in this region more than anywhere else on the west coast (maybe that's recency bias?) I often wonder if part of the reason this section of the coast is the way it is is due to tropical systems, and also part of the reason why very few people live there.

[galaxy401]

Could the rapid intensification of John hinder this storm at least in the short term? Since John is quickly becoming a hurricane, will that push wind shear into future Helene or is it too far away to be affected by it?

[ScottNAtlanta]

Could the rapid intensification of John hinder this storm at least in the short term? Since John is quickly becoming a hurricane, will that push wind shear into future Helene or is it too far away to be affected by it?

John is forecast to move inland shortly and dissipate

[psyclone]

The radii of gale and storm force winds may ultimately prove more important than absolute peak intensity as this system is moving toward an area insanely vulnerable to surge. Steve Lyons on TWC used to say that Apalachee bay is the most surge prone area in the entire Atlantic basin. I believe it. Another high water mark at St Marks looks like a given if the center moves near or west of there. The surge risk in the nature coast and down the west coast will be highly dependent on how large and how close the storm tracks to the coast but it looks to be substantial and worthy of evacuations...

I would agree with that, but it's also one the least populated part of the Florida coastline, it's all mangroves there. Hurricanes also seem to make landfall in this region more than anywhere else on the west coast (maybe that's recency bias?) I often wonder if part of the reason this section of the coast is the way it is is due to tropical systems, and also part of the reason why very few people live there.

It's a swamp that's why no one lives there. There are no beaches because there is no wave action....and there's no wave action because the water is too shallow to allow wave energy to propagate to the coast. The shallow shelf and corner of the Gulf explains the surge potential. Water sloshes at a maximum in the corners of the bathtub.

[Teban54]

NHC forecast for Harvey 60 hours before landfall:

INIT 23/1500Z 21.5N 92.5W 30 KT 35 MPH
12H 24/0000Z 22.3N 93.2W 35 KT 40 MPH
24H 24/1200Z 23.8N 93.9W 40 KT 45 MPH
36H 25/0000Z 25.2N 94.9W 50 KT 60 MPH
48H 25/1200Z 26.7N 96.3W 60 KT 70 MPH
72H 26/1200Z 29.0N 97.3W 40 KT 45 MPH...INLAND
96H 27/1200Z 29.8N 96.9W 35 KT 40 MPH...INLAND
120H 28/1200Z 30.0N 95.0W 35 KT 40 MPH...INLAND

NHC forecast for Michael 80 hours before landfall:

INIT 07/0900Z 18.6N 86.9W 30 KT 35 MPH
12H 07/1800Z 19.4N 86.7W 35 KT 40 MPH
24H 08/0600Z 20.8N 86.4W 45 KT 50 MPH
36H 08/1800Z 22.3N 86.6W 50 KT 60 MPH
48H 09/0600Z 23.9N 87.1W 55 KT 65 MPH
72H 10/0600Z 27.6N 87.3W 65 KT 75 MPH
96H 11/0600Z 32.0N 84.0W 45 KT 50 MPH...INLAND
120H 12/0600Z 37.0N 76.0W 45 KT 50 MPH...NEAR THE VA COAST

NHC forecast for Laura 75 hours before landfall:

INIT 24/0300Z 20.1N 76.6W 55 KT 65 MPH...NEAR CUBA
12H 24/1200Z 21.1N 79.4W 55 KT 65 MPH...NEAR CUBA
24H 25/0000Z 22.5N 82.6W 60 KT 70 MPH...NEAR CUBA
36H 25/1200Z 23.8N 85.7W 65 KT 75 MPH
48H 26/0000Z 25.3N 88.5W 70 KT 80 MPH
60H 26/1200Z 27.1N 90.9W 80 KT 90 MPH
72H 27/0000Z 29.2N 92.4W 90 KT 105 MPH...NEAR THE COAST
96H 28/0000Z 34.2N 90.9W 40 KT 45 MPH...INLAND
120H 29/0000Z 37.4N 83.7W 25 KT 30 MPH...POST-TROP/REMNT LOW

NHC forecast for Ida 73 hours before landfall:

INIT 26/1500Z 16.9N 79.2W 30 KT 35 MPH
12H 27/0000Z 18.2N 80.4W 35 KT 40 MPH
24H 27/1200Z 20.3N 82.0W 45 KT 50 MPH
36H 28/0000Z 22.5N 83.9W 55 KT 65 MPH...INLAND
48H 28/1200Z 24.4N 86.0W 65 KT 75 MPH...OVER WATER
60H 29/0000Z 26.1N 88.1W 80 KT 90 MPH
72H 29/1200Z 27.7N 90.0W 95 KT 110 MPH
96H 30/1200Z 30.5N 92.0W 70 KT 80 MPH...INLAND
120H 31/1200Z 33.7N 91.2W 30 KT 35 MPH...INLAND

NHC forecast for Ian 76 hours before landfall:

INIT 25/1500Z 15.2N 79.8W 45 KT 50 MPH
12H 26/0000Z 16.5N 81.1W 55 KT 65 MPH
24H 26/1200Z 18.1N 82.5W 70 KT 80 MPH
36H 27/0000Z 20.1N 83.7W 90 KT 105 MPH
48H 27/1200Z 22.0N 84.4W 105 KT 120 MPH
60H 28/0000Z 23.9N 84.8W 115 KT 130 MPH
72H 28/1200Z 25.5N 84.8W 115 KT 130 MPH
96H 29/1200Z 28.0N 84.4W 95 KT 110 MPH
120H 30/1200Z 30.3N 83.7W 65 KT 75 MPH...INLAND

NHC forecast for Idalia 80 hours before landfall:

INIT 27/0300Z 21.1N 86.4W 30 KT 35 MPH
12H 27/1200Z 20.9N 86.4W 35 KT 40 MPH
24H 28/0000Z 20.9N 86.2W 40 KT 45 MPH
36H 28/1200Z 21.6N 85.9W 45 KT 50 MPH
48H 29/0000Z 23.1N 85.7W 55 KT 65 MPH
60H 29/1200Z 25.0N 85.5W 65 KT 75 MPH
72H 30/0000Z 27.5N 84.8W 70 KT 80 MPH
96H 31/0000Z 32.7N 81.5W 45 KT 50 MPH...INLAND
120H 01/0000Z 35.2N 76.7W 35 KT 40 MPH...INLAND

And, while not in the Gulf, NHC forecast for Otis just 27 hours before landfall:

INIT 24/0300Z 13.6N 97.9W 45 KT 50 MPH
12H 24/1200Z 14.4N 98.3W 50 KT 60 MPH
24H 25/0000Z 15.5N 98.9W 55 KT 65 MPH
36H 25/1200Z 16.4N 99.5W 60 KT 70 MPH
48H 26/0000Z 17.3N 100.3W 50 KT 60 MPH...INLAND
60H 26/1200Z 18.0N 101.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 27/0000Z...DISSIPATED

[ElectricStorm]

Could the rapid intensification of John hinder this storm at least in the short term? Since John is quickly becoming a hurricane, will that push wind shear into future Helene or is it too far away to be affected by it?

That's what I was wondering yesterday but people here seem to think it won't affect it much. I still think it could at least in the short term, but once it's in the gulf there's probably not much stopping this from becoming a major

[underthwx]

What worries me...are the NHC intensities listed in the first advisory on PTC 9......I will not be surprised to see these intensities rise....as the soon to be cyclone gains strength....not to be an alarmist....but these possibilities have already justified everyone's immediate attention....give thought to getting out of this systems way....until it passes....I am so sorty yall have to go thru this.....true that....

[BobHarlem]

Ian's first advisory was 9 also, fwiw, so even if not an I storm...

[Blown Away]

The NNE angle has been very consistent, it’s all about how far W does #9 go before turning…