ATL: Tropical Depression Fay

[Honeyko]

The surface easterlies accompanying it appear to be sufficiently strong enough to decouple 92L vertically and strip out any LLC should steering force a MLC too far to the right at this time.

not true at all... if the easterlies were strong, the llc would be west of the convection... it is as of right now, the other way around... and you were talking about sal.. and i said, no way.. the sal is weak and a non factor.. plain and simple...

Please attend to the qualifier (bolded). The SAL is presently a non-factor because 92L isn't being shoved rightward across it -- it's happily rolling along like a marble on the south side. But in order for those rightward Virgin Island track models to verify, it'd have to cut across...and I just don't see that happening.

[Scorpion]

[x-y-no]

The following post is NOT an official prognosis.

There is one important fact. The models that depict a track directly over the northern Leeward Islands (i.e. Canadian/UKMET) indicate a deeper system within the next ~24 hours. This is clearly not viable, as demonstrated by available data. Although the low level dry air within the boundary layer is gradually mixing out, the thermodynamic environment remains relatively stable, as evidenced by the SAL to the west and northwest. WV data supports this hypothesis as well. It will not preclude deepening, but it will prohibit more rapid organization. Based on the H7-H85 streamline analysis and TAFB surface analysis, a track further south (toward the S Leewards and Puerto Rico/Hispaniola) is more realistic. Although the thermodynamic environment is marginally conducive, upper level divergence (aided by an upper low to the north) and diffluence is excellent. Based on all available data, a TS is probable for the Lesser Antilles in the vicinity of the southern Leewards, and residents should closely monitor this system.

Personally, a significant interaction with Hispaniola could eventually occur, so any long term intensity estimates hinge on the TC's track. If the TC directly strikes Hispaniola, any inner core could be disrupted, especially if it is compact. On the other hand, if the TC skirts the NE coastline of Hispaniola, any detrimental impacts on intensification may be limited to the short term. However, evidence suggests the "warning cries" for Florida are unwarranted, since it is extremely early.

I'd point out that the shallower steering is more northerly than the deeper steering. So I'm not so persuaded by this reasoning.

I do expect a somewhat more left track than models indicate, but not because I expect the system to be shallower than the models predict.

[MiamiensisWx]

The following post is NOT an official prognosis.

There is one important fact. The models that depict a track directly over the northern Leeward Islands (i.e. Canadian/UKMET) indicate a deeper system within the next ~24 hours. This is clearly not viable, as demonstrated by available data. Although the low level dry air within the boundary layer is gradually mixing out, the thermodynamic environment remains relatively stable, as evidenced by the SAL to the west and northwest. WV data supports this hypothesis as well. It will not preclude deepening, but it will prohibit more rapid organization. Based on the H7-H85 streamline analysis and TAFB surface analysis, a track further south (toward the S Leewards and Puerto Rico/Hispaniola) is more realistic. Although the thermodynamic environment is marginally conducive, upper level divergence (aided by an upper low to the north) and diffluence is excellent. Based on all available data, a TS is probable for the Lesser Antilles in the vicinity of the southern Leewards, and residents should closely monitor this system.

Personally, a significant interaction with Hispaniola could eventually occur, so any long term intensity estimates hinge on the TC's track. If the TC directly strikes Hispaniola, any inner core could be disrupted, especially if it is compact. On the other hand, if the TC skirts the NE coastline of Hispaniola, any detrimental impacts on intensification may be limited to the short term. However, evidence suggests the "warning cries" for Florida are unwarranted, since it is extremely early.

I'd point out that the shallower steering is more northerly than the deeper steering. So I'm not so persuaded by this reasoning.

I do expect a somewhat more left track than models indicate, but not because I expect the system to be shallower than the models predict.

I agree that a deeper TC would track more west/west-northwest as well, but the low level steering does not suggest a track along the northern Leewards or farther north.

[x-y-no]

The surface easterlies accompanying it appear to be sufficiently strong enough to decouple 92L vertically and strip out any LLC should steering force a MLC too far to the right at this time.

not true at all... if the easterlies were strong, the llc would be west of the convection... it is as of right now, the other way around... and you were talking about sal.. and i said, no way.. the sal is weak and a non factor.. plain and simple...

Please attend to the qualifier (bolded). The SAL is presently a non-factor because 92L isn't being shoved rightward across it -- it's happily rolling along like a marble on the south side. But in order for those rightward Virgin Island track models to verify, it'd have to cut across...and I just don't see that happening.

That doesn't follow at all. If the steering is more northerly, then the moisture envelope will also track more northerly. Storms don't move in isolation across the steering.

[KWT]

Scorpion, is that showing the mid-level circulation trying to wrap around convection or is that just a funny twist of fate that it looks like that?

got decently deep convection regardless.

[cheezyWXguy]

The surface easterlies accompanying it appear to be sufficiently strong enough to decouple 92L vertically and strip out any LLC should steering force a MLC too far to the right at this time.

not true at all... if the easterlies were strong, the llc would be west of the convection... it is as of right now, the other way around... and you were talking about sal.. and i said, no way.. the sal is weak and a non factor.. plain and simple...

Please attend to the qualifier (bolded). The SAL is presently a non-factor because 92L isn't being shoved rightward across it -- it's happily rolling along like a marble on the south side. But in order for those rightward Virgin Island track models to verify, it'd have to cut across...and I just don't see that happening.

Dude. Come on. 1. SAL doesnt steer a TC. 2. SAL is very weak. Probably a yellow on the cimss diagram.what ur seeing on wv is upperlevel dry air. Dry air does not mean sal, but it likely wont affect it anyway, because this has a good moisture envelope.

[Ivanhater]

[Scorpion]

Scorpion, is that showing the mid-level circulation trying to wrap around convection or is that just a funny twist of fate that it looks like that?

got decently deep convection regardless.

Yep it looks like convection is starting to wrap around.

[ConvergenceZone]

I would be shocked if this isn't a depression by sometime tomorrow. It just looks too damn good(by good I mean to remain a wave, I know it's still disorganized)....

[caribepr]

The following post is NOT an official prognosis.

There is one important fact. The models that depict a track directly over the northern Leeward Islands (i.e. Canadian/UKMET) indicate a deeper system within the next ~24 hours. This is clearly not viable, as demonstrated by available data. Although the low level dry air within the boundary layer is gradually mixing out, the thermodynamic environment remains relatively stable, as evidenced by the SAL to the west and northwest. WV data supports this hypothesis as well. It will not preclude deepening, but it will prohibit more rapid organization. Based on the H7-H85 streamline analysis and TAFB surface analysis, a track further south (toward the S Leewards and Puerto Rico/Hispaniola) is more realistic..

I'm confused here...what do you mean by Northern Leewards and Southern Leewards??? North of the Leewards...and moving west, would be T & C and the Bahamas...south of the Leewards is the Windwards and south of that are the Lesser Antilles. At least...that's how I always knew it, so if I'm wrong, please explain?
Thanks!

[jaxfladude]

Best looking Atlantic Invest so far this season in this location of the Atlantic Ocean JIMHO that is,
This one is a player, sorry to say....

[Extremeweatherguy]

I think 92L will take a track similar to (but not exactly like) David's in 1979...

http://en.wikipedia.org/wiki/Image:David_1979_track.png

It might be slightly further north/south, but ATM this is my best estimate based on what I am hearing and seeing from various sources including: mets, skilled amateurs, models, and my own brain.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[Scorpion]

Yea, hopefully it doesn't hit Hispaniola though. Would seriously disrupt the circulation not to mention kill thousands.

[Honeyko]

The SAL is presently a non-factor because 92L isn't being shoved rightward across it -- it's happily rolling along like a marble on the south side. But in order for those rightward Virgin Island track models to verify, it'd have to cut across...and I just don't see that happening.

Dude. Come on. 1. SAL doesnt steer a TC.

I didn't say it did. But whatever steers the SAL also affects the lower layers of nearby tropical entities, so the two phenomena cannot be contemplated in isolation.

2. SAL is very weak. Probably a yellow on the cimss diagram.what ur seeing on wv is upperlevel dry air. Dry air does not mean sal, but it likely wont affect it anyway, because this has a good moisture envelope.

Again, I wasn't concerning myself with any intensity-inhibiting effects of the SAL, but how one could judge steering by examining it.

In any event, where do you think 92L is going?

[HURAKAN]

Do you have Fay on this system?!?!?

[Mecklenburg]

i am really wondering why the GFS still doesn't pick up this system

[Recurve]

I'm confused here...what do you mean by Northern Leewards and Southern Leewards??? North of the Leewards...and moving west, would be T & C and the Bahamas...south of the Leewards is the Windwards and south of that are the Lesser Antilles. At least...that's how I always knew it, so if I'm wrong, please explain?
Thanks!

All you Caribbean people know better than I, but my geography says there's the Leewards (they're to leeward, downwind) and Windwards (upwind). Both chains comprise the Lesser Antilles, which are all the islands east of the Greater Antilles (Cuba, Hispaniola, Puerto Rico). The Bahamas are a separate thing.

There's also the ABC islands down there, which are west of the Windwards just north of South America.

Here's some reading: http://en.wikipedia.org/wiki/Lesser_Antilles

[curtadams]

That quickscat shows the system is still attached to the ITCZ on the west. Definitely no center yet.

[ConvergenceZone]

i am really wondering why the GFS still doesn't pick up this system

Well, the models can be wrong too, and this is one time where I think the GFS is wrong....Who knows, perhaps if will come around in time.... The only other explanation is that perhaps GFS is seeing something ahead of it that we aren't, although that's probably the less likely explanation.