ATL: DORIAN - Post-Tropical - Discussion

[GCANE]

Anti-cyclone has now moved to the west of the LLC.

It will now be tracking into the anti-cyclone allowing its vorticity column to expand vertically and spin up.

It appears to has a large stretch ahead of increasing tropopause height which will give it a good chance to strengthen into a TD and possible TS.

[wxman57]

Does it happen often that a system that newly off Africa has such high chances of development? Haven't paid attention to the models and such until this year so I don't have anything to compare it to.

On a side note, Eric Berger (Science Blogger, not a pro-met, from a Houston newspaper) gives a conflicting outlook on 98L: (I don't know how to link text: http://www.beaumontenterprise.com/news/ ... 681823.php)

First he's very, "Meh - don't worry about it. It won't make it into the Gulf" and then likens it to two of the worst storms Texas has ever seen.

If a system has a well-defined LLC then it's not uncommon for it to be given a high chance of development. NHC is the organization that both estimates chances of development AND decides if it has developed, so when they go higher with the percent chance of development it means they're considering naming it.

I red Eric Berger's blog entry and in no way does he liken 98L to Ike or the 1900 Galveston hurricane. He simply says that development of 98L would be a signal that the Cape Verde season is beginning.

[cycloneye]

Last visible image of this day.

[cycloneye]

Very interesting that LGEM makes it a hurricane.

[cycloneye]

[andrewp23]

Beginner question here. Does a higher intensity storm tend to recurve north and out to sea? Does a lower intensity storm tend to continue west?
If at 48 hrs this begins to taper off like the intensity forecast shows, would that allow the remnants to continue west towards the leewards and have a chance to reform if the conditions are favorable?

Thanks!

[RL3AO]

Beginner question here. Does a higher intensity storm tend to recurve north and out to sea? Does a lower intensity storm tend to continue west?
If at 48 hrs this begins to taper off like the intensity forecast shows, would that allow the remnants to continue west towards the leewards and have a chance to reform if the conditions are favorable?

Thanks!

A stronger storm tends to get steered by a different level of the atmosphere then a weaker one. You can see the steering winds here.

http://tropic.ssec.wisc.edu/real-time/d ... oom=&time=

To be honest. The ridge is so strong over the North Central Atlantic, that this thing is not going to recruve east of Bermuda no matter how strong it gets IMO.

[artist]

http://moe.met.fsu.edu/cgi-bin/ecmwf-op ... =Animation
ECMWF animation

[gatorcane]

12Z FIM (Finite-volume Icosahedral Model) from Earth System Research Laboratory is more bullish than it was in the 06Z run.

12Z at 168 hours:



06Z at 168 hours:

[Blown Away]

Very interesting that LGEM makes it a hurricane.

http://oi44.tinypic.com/2w50f85.jpg

Doesn't the NHC rely somewhat on the LGEM for intensity predictions?? SHIP/DSHP up to Cane, so that should reflect in the next update??

[Senobia]

I red Eric Berger's blog entry and in no way does he liken 98L to Ike or the 1900 Galveston hurricane. He simply says that development of 98L would be a signal that the Cape Verde season is beginning.

Thank you for your answer about the development percentages. But what I was asking is - it's at 60% already. And it's not very far off the coast of Africa. Does this happen often and is it a precursor to a bigger/stronger storm, because it was so well-defined from the beginning?

In reference to Berger's blog, this is what he followed the initial statement that you referenced with:

Storms that form in this region and track westward across the Atlantic Ocean are often the most powerful and dangerous storms that form in a given hurricane season. The two most destructive hurricanes to have hit the upper Texas coast, Hurricane Ike in 2008 and the Great Storm of 1900, were both Cape Verde hurricanes.

And then he backs off again:

This is not to say one should panic. Invest 98L probably won't have a significant effect on the United States.

[RL3AO]

Here comes the dry air...

[Riptide]

Here comes the dry air...

Sarcasm? Looks pretty good but could be better for 98L.

[RL3AO]

No if you watch the loop you can see the dry air moving SW towards the wave.

[RL3AO]

Forecast soundings from GFS for 48 and 96 hours. I picked a spot just ahead of the center that the GFS was forecasting. I notice two things.

1) Its not terribly dry at the mid-levels.
2) Wind shear. 25 to 35! knot winds at 850mb, while you have 10 to 15kt at 400mb or so.

[MGC]

Needs a bit more convection to be upgraded IMO.....MGC

[TropicalAnalystwx13]

DMAX in a few hours should help with that. I think this will be classified in the morning.

[floridasun78]

Very interesting that LGEM makes it a hurricane.

http://oi44.tinypic.com/2w50f85.jpg

Doesn't the NHC rely somewhat on the LGEM for intensity predictions?? SHIP/DSHP up to Cane, so that should reflect in the next update??

i think their do nhc use ship in their forecast of system

[blp]

http://moe.met.fsu.edu/cgi-bin/ecmwf-opertc2.cgi?time=2013072312&field=850mb+Vorticity&hour=Animation
ECMWF animation

Looking at that animation it would need to move NW now and keeping moving that way for that run to verify.

[SFLcane]

Looks like an Ike/France's type tracks here being portrayed by some models