ATL: CRISTOBAL - Post-Tropical - Discussion

[hurricanehunter69]

:uarrow: anti-cyclone aloft....couldnt be any better IMO

good to be back!!

Well I be damned...was wonderin where you were at!

[CaneCurious]

Does anyone know when Levi Cowan will post another video update?

[cycloneye]

Does anyone know when Levi Cowan will post another video update?

He did this video on Wednesday afternoon.

http://www.tropicaltidbits.com/blog/201 ... erception/

[CaneCurious]

Does anyone know when Levi Cowan will post another video update?

He did this video on Wednesday afternoon.


Thanks Cycloneye!

[somethingfunny]

Until now we've had two main camps of models regarding this cyclogenesis - the GFS, UKMET, and ECMWF (among others) were developing 96L very slowly and letting it move westward to the south of the large Caribbean islands until it potentially coalesces as it enters the Gulf, and the CMC, FIM, and HWRF (among others) were developing 96L very quickly and introducing an almost immediate north/northwest motion toward Puerto Rico and Dominican Republic with a strengthening storm which allows for eventual recurvature or a Florida/EastCoast threat.

I've been of the opinion that slow development of 96L was more likely and we'd see most of the other models shifting southwestward towards a Central America or Gulf of Mexico threat, because this sort of elongated monsoon trough in the ITCZ usually takes a while to become focused on one tight circulation center. Levi Cowan's video from yesterday explained this scenario in which the trailing wave catches up to and then slowly merges with the leading wave as the whole disorganized mess slowly develops while crawling westward. Here's a 850mb vorticity analysis from yesterday which shows these two waves - I'm going to post a current vorticity analysis in a moment.





^ Today the satellite trends indicate that we're getting a quick development and northward motion after all, however I'm still not convinced that it's occurring like that and I'm writing a hypothetical analysis just to throw this idea at the wall and see if you guys think it could stick.

What we have here is the wave to the east, the one with the 10/20 NHC probabilities yesterday, is moving west faster than the southwestern lobe and is almost directly north of it now. Weak cyclonic turning in the southern portion may have helped to get the northern lobe spinning more quickly, but this should get the southern portion spinning as well and we could end up with an elongated circulation or perhaps competing circulations. This elongation is reflected in the ASCAT image despite what at first looks like a tight circulation on satellite, and the current vorticity analysis still shows equal vorticity along the entire axis of this now-combined wave.





Once the northern, seemingly dominant portion of this wave moves off to the northwest of the southern portion, what happens? Does it just break free of the ITCZ and leave behind whatever vorticity it didn't absorb? Or does the southern (at that point southeastern) lobe act like a stretched out rubber band and pull that tighter circulation back in towards it? Although it seems like 96L is developing rapidly, it could be about to unravel as it works out where this circulation is actually going to become focused. If that happens, we'll have a broad, messy circulation slowly organizing as it pushes westward, and the computer models would shift toward the Gulf and limit development (if any) until it reaches that area.

Obviously I'm no expert on the dynamical physics of all this, but I'm a little bit suspicious of this developing so quickly, even despite today's model runs mostly agreeing that this is exactly how it's going to happen. This might be my last chance to throw this opinion out there, since 96L might prove me irrevocably wrong by tomorrow.

[NDG]

Is starting to get that look of an organizing tropical cyclone.

[SouthDadeFish]

Latest ASCAT pass shows a LLC starting to form:



However, current IR imagery shows cloud tops starting to warm a bit...

[cycloneye]

Still a bit broad.

[floridasun78]

hope islands got time get ready look like getting stronger per hour 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

[NDG]

But getting better compared to earlier.

[SouthDadeFish]

:uarrow: Still a bit broad.

Yes, but the pass is missing some data, and that is still a marked improvement from the pass an hour earlier. Starting to see outflow improving in all quadrants on satellite. I think one more convective burst can put this over the top and become a TC.

My forecast: If we get another strong convective burst before sunrise, recon will probably find a TC tomorrow afternoon. If not, then who knows

To be honest, conditions seem favorable. Not quite sure why the models aren't eager to develop this before it crashes into some mountains...

[floridasun78]

i bet nhc thinking issue avd at 5am for area could be td by that time

[Hurricaneman]

:uarrow: Still a bit broad.

Yes, but the pass is missing some data, and that is still a marked improvement from the pass an hour earlier. Starting to see outflow improving in all quadrants on satellite. I think one more convective burst can put this over the top and become a TC.

My forecast: If we get another strong convective burst before sunrise, recon will probably find a TC tomorrow afternoon. If not, then who knows

To be honest, conditions seem favorable. Not quite sure why the models aren't eager to develop this before it crashes into some mountains...

could be a case of the models not having a clear cut circulation center to work with yet and could still be working a 2 vort deal which would be almost completely wrong

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

[Blown Away]

Great satellite presentation ATM... But it's hard to discount the GFS/Euro showing very little/if any development for days... Will we see a decline in 96L to be in line with the globals???

[xtyphooncyclonex]

Impressive. It's FINALLY cranking up. Not surprised to see a hurricane later in the week, and that this would bring the ACE above average (again) as it traverses boiling hot SSTs and unusually high TCHP. And since when has a hurricane made landfall over the area that this may hit?

[xtyphooncyclonex]

Although, it may trek over some dry air to its east or northeast.

[meriland23]

I am curious. Would a stronger storm bring this more westward or does the strength of the storm have little to do with the path of this specific storm?

[xtyphooncyclonex]

I am curious. Would a stronger storm bring this more westward or does the strength of the storm have little to do with the path of this specific storm?

A met said before that the stronger it is, the more westward it goes. A weaker storm would move faster and move in another direction.

[Yellow Evan]

I am curious. Would a stronger storm bring this more westward or does the strength of the storm have little to do with the path of this specific storm?

A met said before that the stronger it is, the more westward it goes. A weaker storm would move faster and move in another direction.

That doesn't make sense to me. 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.

[xtyphooncyclonex]

Well, in some cases, like in Hurricane Irene, it doesn't matter. Despite its strength, it had tracked more northward and struck the Northeast US.

But...

Hurricane Hugo in 1989 was a category 5 which moved Westward or WEST-NW, but as it weakened it shifted its course towards the Carolinas. Which that may be a proof that the statement of the pro met was right.