ATL: CHANTAL - Post-Tropical

[Gustywind]

Tracking Info For Invest 95L

http://www.wunderground.com/tropical/at ... track.html


18 GMT 07/6/13 8.0N 34.8W 25 1009 Invest
00 GMT 07/7/13 8.2N 36.4W 25 1009 Invest

[SFLcane]

0z Models guidance

3rd time the charm? Still no intensity forecast on it.

EDIT: I got an strange error that said, "The requested post does not exist" ... never seen that one before. The 3rd repeat is now also removed.

[blp]

850mb vorticity much improved than 3hrs ago.

3hrs ago:


Current:

[cycloneye]

Low level convergence is much more tight now than in the past 6-12 hours.

[bvigal]

I think this looks healthy, and I thought so yesterday, too. I know about the SAL, but it didn't look like that big a factor. It may be sucking in a tiny bit now, but doubt it's enough to kill it completely. The SAL product doesn't show the height. If you live in the islands, you've seen days when the SAL looked like you'd be choking in haze and you look out at a sharp horizon - the SAL is high up. I always look at the water vapor, too. Sometimes you see moisture there that is in exact same spot as some of the SAL. Also, I've seen lows pull enough moisture up from equator and just chug right through what we see on SAL product. Other factors besides SAL: NO shear (the biggest positive factor) unbelievable 0-10kt until this afternoon when near that area of up to 20kt just to the north, and no shear past there all the way to EC islands; vorticity showing on surface now through 500mb, increasing convergence, divergence, good shape for over 24hrs, convection fairly consistant. Really, what else do we need to say this a healthy wave and will likely not go "poof"?

[Alyono]

I have no idea as to why NHC says environmental conditions will be more favorable in a few days. All indications from the models are for a significant increase in shear as this approaches the islands.

As for its current state, easterly wind shear is taking its toll on this this evening. The center is well east of the convection. Still a 50 percent chance of development through the next 48, but if it doesnt develop within that time period, it likely wont develop it at all

[TropicalAnalystwx13]

I have no idea as to why NHC says environmental conditions will be more favorable in a few days. All indications from the models are for a significant increase in shear as this approaches the islands.

As for its current state, easterly wind shear is taking its toll on this this evening. The center is well east of the convection. Still a 50 percent chance of development through the next 48, but if it doesnt develop within that time period, it likely wont develop it at all

There's always a chance it develops in the Bahamas region, northwestern Caribbean, or eastern Gulf of Mexico in about a week. Flow on the southwest side of a high is always slower which helps air pile (you already know this). The CMC indicates a tropical storm, and the GFS, while not enthusiastic at all, does show an area of low pressure southeast of Louisiana in roughly the same time.

[bvigal]

Well my account with the picture storage is inactive so I can't store a pic of the shear, but at http://tropic.ssec.wisc.edu/real-time/a ... wg8sht.GIF this system is in blue, which the key says is 0 to 10kt of shear. I guess I've been reading that map wrong all these years,

[blp]

Here is another view. It is almost there and elongated.

[gatorcane]

I have no idea as to why NHC says environmental conditions will be more favorable in a few days. All indications from the models are for a significant increase in shear as this approaches the islands.

As for its current state, easterly wind shear is taking its toll on this this evening. The center is well east of the convection. Still a 50 percent chance of development through the next 48, but if it doesnt develop within that time period, it likely wont develop it at all

I don't see the shear models are seeing and that some other folks have mentioned. There is a ULL passing north of Hispaniola that is moving briskly west underneath the steering of a powerful Bermuda High ridge to the north. Once that clears out, I don't see any shear in the vicinity of the islands at all. What weather system is going to cause all this shear?

But i don't think it will matter anyway, SAL is already getting to this little system along with some easterly shear now as you mention and I think it's on it's way on out. Will likely not be nearly as impressive looking by tomorrow with much less convection. Likely the NHC will need to downgrade development chances over the next day or so.

[ozonepete]

SAL doesn't always mean no development. It is situated in a nice pocket of moist air in the mid and upper levels. the SAL is lagging behind the system and to the north. so far considering all that have mentioned sal being around it have not noticed despite it the convection has not only maintained but increased this afternoon.

http://tropic.ssec.wisc.edu/real-time/m ... t72hrs.gif

Thanks for saying that. SAL is often way over-rated as a limiting factor. I've seen many systems with heavy SAL just to the north that never ingested any of it, or even more interesting, ingested some of it and developed anyway. There is a lot more research that needs to be done on the influence of the SAL, especially because very moist air can hold a lot of dust but it's still very moist, which is all that counts. The precipitable water flow is a much better measure. And looking at this system it's really hard to see how it's choking on dust when there's so much convection going on.

[floridasun78]

i see all storm are to west of circulation

[NDG]

Just by the looks of its satellite presentation, easterly shear seems to be more of the problem in all levels of the atmosphere thus why it may have a problem closing a circulation off at the surface.
Tonight's 0z GFS model has it approaching Barbados Monday night, that is a fast track westward!

[CrazyC83]

Just by the looks of its satellite presentation, easterly shear seems to be more of the problem in all levels of the atmosphere thus why it may have a problem closing a circulation off at the surface.
Tonight's 0z GFS model has it approaching Barbados Monday night, that is a fast track westward!

Sometimes they can still manage to thrive especially with an anticyclone above, but it tends to be hit and miss. Charley in 2004 was a good example.

[CrazyC83]

Updated:

That seems quite reasonable given the trough pattern. I see any north turn being near 80W.

[meriland23]

Howy people! Coming back to storm2k this season, looking at this new invest. So what are your guyses 'opinions' on what is going on/ will happen.. IYO

[meriland23]

Updated:

That seems quite reasonable given the trough pattern. I see any north turn being near 80W.

If that does not make a turn by 75 w .. that could spell trouble. Hard to determine the intensity given the shear forecast.

[ROCK]

95L is being sheared....convection displaced from the MLC to the west. Also it is booking it west at a good clip.....

[hurricaneCW]

Clearly it's going to struggle for several days, it's moving too fast to develop but it's a strong and vigorous way and it'll be interesting to see what happens once it gets to past 75W when things might be a lot more favorable for it to develop.

[ozonepete]

Here's the 00Z run synopsis from Colorado State. Given all that's being said here, and all that's being output by the models, the graphics here seem like a pretty decent estimate as to what will happen as of now. A tropical storm within 48 hours and approaching the Antilles islands in 72 hours. Earlier the models had a cat 1 hurricane in 72 hours. So we can assume they will bounce back and forth on the intensity over the next couple of days (because they still don't do well with intensity) but since they are so good at track the expected track should probably (roughly) pan out.