ATL: DORIAN - Post-Tropical - Discussion

[gatorcane]

New video from Levi. A must watch. He explains how much uncertainty there is here. He definitely is not taking South Florida off the table. The UKMET ensembles he posted are really interesting. Seems most are into SE Florida.

https://www.tropicaltidbits.com/

[supercane4867]

Is the AF plane turning back to the storm? It's confused just like Dorian itself

[ozonepete]

Attempting to ask this again. Sincere questions from someone who has lurked for many seasons.

Couple of basic questions.

1. Once the storm becomes a major of this intensity, isn’t it possible for it to start tracking poleward?
2. And also, if it sits over the Bahamas for days as a 4 or 5, is it likely to be able to retain the same degree of strength for that length of time?

A few TV mets have said stronger might end up more west this time since there's no large scale trough in the area, but I'm not 100% sure if that's the case or not.

As far as stalling, if it sits for several days it's likely to weaken due to drier air from land, as well as upwelling, but that's by no means an absolute guarantee. Frances in 2004 was a good example of this happening.

I have seen both ideas, that a strong TC veers right or left of the expected path, and never seen any research to support either. I stand corrected if there are any papers out there but I haven't seen any nor any established NHC forecast methods that hold it to be true and/or use it. There is the Beta efect, which causes TCs to move to the right of the expected track as they move westward in the northern hemisphere, but models account for this and I've never heard that it is more pronounced for stronger storms.

The big thing if it stalls over the Bahamas is upwelling, because a very powerful storm can suck up all of the ocean heat below it pretty quickly. But it takes a day or two, and since this storm is not forecast to sit for more than 24 hours, it will probably move on northward before it starts to upwell too much cooler water. If it stals over land it will of course peter out rapidly.

[abajan]

Attempting to ask this again. Sincere questions from someone who has lurked for many seasons.

Couple of basic questions.

1. Once the storm becomes a major of this intensity, isn’t it possible for it to start tracking poleward?
2. And also, if it sits over the Bahamas for days as a 4 or 5, is it likely to be able to retain the same degree of strength for that length of time?

...

As for the second question, if it moves too slowly for too long a period of time, a hurricane will upwell cold water beneath it. While steering is weak, this is a possibility for Dorian, but I can't say personally how much of a possibility at this time.

It's just occurred to me that the waters around the Bahamas are very shallow. (I think I recall seeing videos of people walking miles into the sea with the water just knee high.) So, I'm wondering if there's any cold water to upwell or if it's all warm.

[Jr0d]

Attempting to ask this again. Sincere questions from someone who has lurked for many seasons.

Couple of basic questions.

1. Once the storm becomes a major of this intensity, isn’t it possible for it to start tracking poleward?
2. And also, if it sits over the Bahamas for days as a 4 or 5, is it likely to be able to retain the same degree of strength for that length of time?

With regards to the first question, what you're probably thinking of is beta drift, which is indeed a real thing. In a purely unidirectional steering regime, a stronger circulation will tend to bend more poleward than a weaker circulation in the same regime. However, the current steering regime is not that straightforwards, with a deep layer ridge forcing a stronger system more westwards in the near term before things become more nebulous with multiple entities exerting only weak influences. If a sufficient break in ridging develops, it may try to take that route out, but it is very unclear whether that will transpire or not with the information we have now.

As for the second question, if it moves too slowly for too long a period of time, a hurricane will upwell cold water beneath it. While steering is weak, this is a possibility for Dorian, but I can't say personally how much of a possibility at this time.

It also should be noted that upwelling in the Gulf stream is not nearly as significant as the warm Gulf stream water will replenish itself.

[Hammy]

Is the AF plane turning back to the storm? It's confused just like Dorian itself

SFMR appears broken (there's no sfc wind data) but they might be trying to fix it, or they might just try and go based on flight level.

[Nancy Smar]

AL, 05, 2019083100, 03, OFCL, 0, 253N, 710W, 115, 0, HU, 34, NEQ, 90, 90, 60, 80, 0, 0, 0, 140, 0, , 0, DPB, 310, 8, , , 12, NEQ, 120, 90, 60, 105,
AL, 05, 2019083100, 03, OFCL, 0, 253N, 710W, 115, 0, HU, 50, NEQ, 50, 50, 40, 40, 0, 0, 0, 140, 0, , 0, DPB, 310, 8, , , 12, NEQ, 120, 90, 60, 105,
AL, 05, 2019083100, 03, OFCL, 0, 253N, 710W, 115, 0, HU, 64, NEQ, 25, 25, 20, 20, 0, 0, 0, 140, 0, , 0, DPB, 310, 8, , , 12, NEQ, 120, 90, 60, 105,
AL, 05, 2019083100, 03, OFCL, 3, 255N, 714W, 120, 948, HU, 34, NEQ, 90, 90, 60, 80, 0, 0, 0, 145, 0, , 0, DPB, 300, 9, , , 12, NEQ, 120, 90, 60, 120,
AL, 05, 2019083100, 03, OFCL, 3, 255N, 714W, 120, 948, HU, 50, NEQ, 50, 50, 40, 40, 0, 0, 0, 145, 0, , 0, DPB, 300, 9, , , 12, NEQ, 120, 90, 60, 120,
AL, 05, 2019083100, 03, OFCL, 3, 255N, 714W, 120, 948, HU, 64, NEQ, 25, 25, 20, 20, 0, 0, 0, 145, 0, , 0, DPB, 300, 9, , , 12, NEQ, 120, 90, 60, 120,
AL, 05, 2019083100, 03, OFCL, 12, 259N, 728W, 130, 0, HU, 34, NEQ, 90, 90, 60, 80, 0, 0, 0, 160, 0, , 0, DPB, 290, 9,
AL, 05, 2019083100, 03, OFCL, 12, 259N, 728W, 130, 0, HU, 50, NEQ, 50, 50, 40, 40, 0, 0, 0, 160, 0, , 0, DPB, 290, 9,
AL, 05, 2019083100, 03, OFCL, 12, 259N, 728W, 130, 0, HU, 64, NEQ, 25, 25, 20, 20, 0, 0, 0, 160, 0, , 0, DPB, 290, 9,
AL, 05, 2019083100, 03, OFCL, 24, 263N, 745W, 130, 0, HU, 34, NEQ, 100, 90, 60, 90, 0, 0, 0, 160, 0, , 0, DPB, 285, 8,
AL, 05, 2019083100, 03, OFCL, 24, 263N, 745W, 130, 0, HU, 50, NEQ, 50, 50, 40, 50, 0, 0, 0, 160, 0, , 0, DPB, 285, 8,
AL, 05, 2019083100, 03, OFCL, 24, 263N, 745W, 130, 0, HU, 64, NEQ, 25, 25, 20, 25, 0, 0, 0, 160, 0, , 0, DPB, 285, 8,
AL, 05, 2019083100, 03, OFCL, 36, 266N, 760W, 125, 0, HU, 34, NEQ, 100, 90, 60, 90, 0, 0, 0, 150, 0, , 0, DPB, 285, 7,
AL, 05, 2019083100, 03, OFCL, 36, 266N, 760W, 125, 0, HU, 50, NEQ, 50, 50, 40, 50, 0, 0, 0, 150, 0, , 0, DPB, 285, 7,
AL, 05, 2019083100, 03, OFCL, 36, 266N, 760W, 125, 0, HU, 64, NEQ, 25, 25, 20, 25, 0, 0, 0, 150, 0, , 0, DPB, 285, 7,
AL, 05, 2019083100, 03, OFCL, 48, 268N, 773W, 125, 0, HU, 34, NEQ, 100, 80, 70, 90, 0, 0, 0, 150, 0, , 0, DPB, 280, 6,
AL, 05, 2019083100, 03, OFCL, 48, 268N, 773W, 125, 0, HU, 50, NEQ, 50, 50, 40, 50, 0, 0, 0, 150, 0, , 0, DPB, 280, 6,
AL, 05, 2019083100, 03, OFCL, 48, 268N, 773W, 125, 0, HU, 64, NEQ, 30, 25, 20, 30, 0, 0, 0, 150, 0, , 0, DPB, 280, 6,
AL, 05, 2019083100, 03, OFCL, 72, 270N, 786W, 115, 0, HU, 34, NEQ, 100, 90, 70, 80, 0, 0, 0, 140, 0, , 0, DPB, 280, 3,
AL, 05, 2019083100, 03, OFCL, 72, 270N, 786W, 115, 0, HU, 50, NEQ, 50, 50, 40, 50, 0, 0, 0, 140, 0, , 0, DPB, 280, 3,
AL, 05, 2019083100, 03, OFCL, 96, 283N, 805W, 110, 0, HU, 34, NEQ, 0, 0, 0, 0, 0, 0, 0, 135, 0, , 0, DPB, 310, 5,
AL, 05, 2019083100, 03, OFCL, 120, 308N, 812W, 90, 0, HU, 34, NEQ, 0, 0, 0, 0, 0, 0, 0, 110, 0, , 0, DPB, 345, 6,

120kts

[Chris_in_Tampa]

Is the AF plane turning back to the storm? It's confused just like Dorian itself

[tropicwatch]

AF appears to have turned back towards the storm. They have been at operational altitude the whole time. My guess technical issues with equipment.

[aperson]

As GCANE was showing in models yesterday, the TPW fetch for the storm has moved from a wave connected to the ITCZ to a rich moisture tap from the west. I expect there to be major structural changes in Dorian as a result


(ref: http://tropic.ssec.wisc.edu/real-time/m ... anim=anigf)

Interesting to note that Dorian currently has very robust dual inflow and outflow channels right now.

[Aric Dunn]

TPW showing the 25N flow suddenly shifts from east to west into the gulf. it should be turning west soon.. follow up with that above

you can also see the low becoming more defined in the straights. Dorian and that low may interact and keep Dorian more westerly.

[Hammy]

Plane's going north now, not sure what's going on.

[Siker]

AL, 05, 2019083100, 03, OFCL, 0, 253N, 710W, 115, 0, HU, 34, NEQ, 90, 90, 60, 80, 0, 0, 0, 140, 0, , 0, DPB, 310, 8, , , 12, NEQ, 120, 90, 60, 105,
AL, 05, 2019083100, 03, OFCL, 0, 253N, 710W, 115, 0, HU, 50, NEQ, 50, 50, 40, 40, 0, 0, 0, 140, 0, , 0, DPB, 310, 8, , , 12, NEQ, 120, 90, 60, 105,
AL, 05, 2019083100, 03, OFCL, 0, 253N, 710W, 115, 0, HU, 64, NEQ, 25, 25, 20, 20, 0, 0, 0, 140, 0, , 0, DPB, 310, 8, , , 12, NEQ, 120, 90, 60, 105,
AL, 05, 2019083100, 03, OFCL, 3, 255N, 714W, 120, 948, HU, 34, NEQ, 90, 90, 60, 80, 0, 0, 0, 145, 0, , 0, DPB, 300, 9, , , 12, NEQ, 120, 90, 60, 120,
AL, 05, 2019083100, 03, OFCL, 3, 255N, 714W, 120, 948, HU, 50, NEQ, 50, 50, 40, 40, 0, 0, 0, 145, 0, , 0, DPB, 300, 9, , , 12, NEQ, 120, 90, 60, 120,
AL, 05, 2019083100, 03, OFCL, 3, 255N, 714W, 120, 948, HU, 64, NEQ, 25, 25, 20, 20, 0, 0, 0, 145, 0, , 0, DPB, 300, 9, , , 12, NEQ, 120, 90, 60, 120,
AL, 05, 2019083100, 03, OFCL, 12, 259N, 728W, 130, 0, HU, 34, NEQ, 90, 90, 60, 80, 0, 0, 0, 160, 0, , 0, DPB, 290, 9,
AL, 05, 2019083100, 03, OFCL, 12, 259N, 728W, 130, 0, HU, 50, NEQ, 50, 50, 40, 40, 0, 0, 0, 160, 0, , 0, DPB, 290, 9,
AL, 05, 2019083100, 03, OFCL, 12, 259N, 728W, 130, 0, HU, 64, NEQ, 25, 25, 20, 20, 0, 0, 0, 160, 0, , 0, DPB, 290, 9,
AL, 05, 2019083100, 03, OFCL, 24, 263N, 745W, 130, 0, HU, 34, NEQ, 100, 90, 60, 90, 0, 0, 0, 160, 0, , 0, DPB, 285, 8,
AL, 05, 2019083100, 03, OFCL, 24, 263N, 745W, 130, 0, HU, 50, NEQ, 50, 50, 40, 50, 0, 0, 0, 160, 0, , 0, DPB, 285, 8,
AL, 05, 2019083100, 03, OFCL, 24, 263N, 745W, 130, 0, HU, 64, NEQ, 25, 25, 20, 25, 0, 0, 0, 160, 0, , 0, DPB, 285, 8,
AL, 05, 2019083100, 03, OFCL, 36, 266N, 760W, 125, 0, HU, 34, NEQ, 100, 90, 60, 90, 0, 0, 0, 150, 0, , 0, DPB, 285, 7,
AL, 05, 2019083100, 03, OFCL, 36, 266N, 760W, 125, 0, HU, 50, NEQ, 50, 50, 40, 50, 0, 0, 0, 150, 0, , 0, DPB, 285, 7,
AL, 05, 2019083100, 03, OFCL, 36, 266N, 760W, 125, 0, HU, 64, NEQ, 25, 25, 20, 25, 0, 0, 0, 150, 0, , 0, DPB, 285, 7,
AL, 05, 2019083100, 03, OFCL, 48, 268N, 773W, 125, 0, HU, 34, NEQ, 100, 80, 70, 90, 0, 0, 0, 150, 0, , 0, DPB, 280, 6,
AL, 05, 2019083100, 03, OFCL, 48, 268N, 773W, 125, 0, HU, 50, NEQ, 50, 50, 40, 50, 0, 0, 0, 150, 0, , 0, DPB, 280, 6,
AL, 05, 2019083100, 03, OFCL, 48, 268N, 773W, 125, 0, HU, 64, NEQ, 30, 25, 20, 30, 0, 0, 0, 150, 0, , 0, DPB, 280, 6,
AL, 05, 2019083100, 03, OFCL, 72, 270N, 786W, 115, 0, HU, 34, NEQ, 100, 90, 70, 80, 0, 0, 0, 140, 0, , 0, DPB, 280, 3,
AL, 05, 2019083100, 03, OFCL, 72, 270N, 786W, 115, 0, HU, 50, NEQ, 50, 50, 40, 50, 0, 0, 0, 140, 0, , 0, DPB, 280, 3,
AL, 05, 2019083100, 03, OFCL, 96, 283N, 805W, 110, 0, HU, 34, NEQ, 0, 0, 0, 0, 0, 0, 0, 135, 0, , 0, DPB, 310, 5,
AL, 05, 2019083100, 03, OFCL, 120, 308N, 812W, 90, 0, HU, 34, NEQ, 0, 0, 0, 0, 0, 0, 0, 110, 0, , 0, DPB, 345, 6,

120kts

Where do you pull this data?

[Blinhart]

You know it is really crazy when 20 hours ago there was a 5.3 earthquake on Mid-Atlantic Ridge, you don't hear of many earthquakes there.

[HurricaneFrances04]

Is it the AF mission that was supposed to be dropping buoys ahead of the storm?

[Aric Dunn]

Plane's going north now, not sure what's going on.

I was wondering the same thing.. they both are doing odd things. maybe gathering some surrounding data ?

[Chris_in_Tampa]

Plane's going north now, not sure what's going on.

I don't know, maybe they are going back to where they were in the path. But I believe I recall that in the past they have sometimes been called to assist in some capacity if search and rescue is needed. I might be wrong.

Edit: Here is what I was talking about: https://www.afrc.af.mil/News/Article-Di ... nd-rescue/

[AutoPenalti]

Wasn’t one of their missions unassigned?

[HurricaneFrances04]

From earlier today. I wonder if it is the same mission?:

 https://twitter.com/53rdWRS/status/1167470388605018112

[psyclone]

Attempting to ask this again. Sincere questions from someone who has lurked for many seasons.

...

As for the second question, if it moves too slowly for too long a period of time, a hurricane will upwell cold water beneath it. While steering is weak, this is a possibility for Dorian, but I can't say personally how much of a possibility at this time.

It's just occurred to me that the waters around the Bahamas are very shallow. (I think I recall seeing videos of people walking miles into the sea with the water just knee high.) So, I'm wondering if there's any cold water to upwell or if it's all warm.

But super shallow seawater will quickly have it's heat degraded in a severe storm. there might not be cold to upwell but it won't stay hot. I observe this all the time in my area. having said that this storm will not be lacking heat energy even if it does stall for a time in the Bahamas. the water is stupid hot to begin with and there's plenty of deep warm water too. Upwelling is an oversold phenom, especially at peak season. Something else will have to pick on Dorian. As a side note... please tell me it's not just me going bananas awaiting the 11 pm advisory..