Strong Tropical Wave Moving Off Africa

[gatorcane]

We have a strong tropical wave getting to move off Africa tonight and convection has really blown up today. GFS has been showing development of this wave for the past several days and shows development starting around 48 hours. The GEM is also showing a low developing though no other model shows significant development yet.

Latest saved image:


Loop (should work on mobile phones):
http://rammb.cira.colostate.edu/ramsdis ... display=12

18Z GFS (120 hours):


18Z GFS Ensembles (120 hours):

[Ntxw]

Regarding the background state, this wave will have some benefits from a Kelvin wave this week, this is the best time for it to try to organize if it can keep up thunderstorms it has a chance which should be easier with rising air of the CCKW. Week 2 will be suppressed phase.

[Siker]

Regarding the background state, this wave will have some benefits from a Kelvin wave this week, this is the best time for it to try to organize if it can keep up thunderstorms it has a chance which should be easier with rising air of the CCKW. Week 2 will be suppressed phase.

Yeah, in addition days ~6-8 will not be friendly to this system as it will also traverse sub 26°C water.

[fci]

Getting to be that time of year for Cape Verde activity

[TheStormExpert]

Regarding the background state, this wave will have some benefits from a Kelvin wave this week, this is the best time for it to try to organize if it can keep up thunderstorms it has a chance which should be easier with rising air of the CCKW. Week 2 will be suppressed phase.

Yeah, in addition days ~6-8 will not be friendly to this system as it will also traverse sub 26°C water.

Not necessarily, this graphic below shows the maximum potential storm intensity, and even just north of those sub 26ºC waters it can still support a Cat.1-2 hurricane, not saying that is what would become of this just giving examples.

[gatorcane]

I am curious what the NHC will do with this one especially if the 00Z GFS continues to insist on development while the Euro and other models continue to insist on no development. Last week with 94L, the NHC did not hesitate to tag that wave as an invest as soon as it rolled off Africa with basically no model support other than the Euro. This wave rolling of Africa this time continues to build in convection and looks very impressive with even cyclonic rotation already evident, arguably more impressive than the wave that 94L spawned from. We should know by this time tomorrow how well it will do in its new environment once it is completely over water.

[Siker]

Yes it doesn't necessarily mean the death of the storm, but it is a pretty significant negative factor, especially when other conditions are not ideal.

[Siker]

...

[Hammy]

So GFS remains a joke despite the upgrades...

[TheStormExpert]

So GFS remains a joke despite the upgrades...

It's more of a joke with the upgrades!

[Siker]

One thing that I will point out about this run is that a competing area of vorticity develops on the front end of the wave, which is obviously no help to a sprouting storm:



But this is a chicken and the egg type question; it's possible that vort is able to exist because the other half won't develop.

[Yellow Evan]

Why is the GFS's new upgrade being not taken seriously when the wave hasn't even emerged? At least in other basins, the number of phantom GFS storms has been greatly reduced.

[Siker]

Ensemble support is weaker, but still there.

[Hammy]

Why is the GFS's new upgrade being not taken seriously when the wave hasn't even emerged? At least in other basins, the number of phantom GFS storms has been greatly reduced.

It's a bit hard to take seriously when about the same time as the last two years, the GFS starts it's usual trick of showing development, and then dropping it when it comes within 48 hours, also as it did the last two years. Nothing appears to have changed with the upgrades, the only change was that we didn't see the June error (which may have only been because something happened to form then.)

[Kingarabian]

Why is the GFS's new upgrade being not taken seriously when the wave hasn't even emerged? At least in other basins, the number of phantom GFS storms has been greatly reduced.

Well to be fair it's struggling to sniff out storms far out in the pacific as well.

[TheStormExpert]

Why is the GFS's new upgrade being not taken seriously when the wave hasn't even emerged? At least in other basins, the number of phantom GFS storms has been greatly reduced.

It's a bit hard to take seriously when about the same time as the last two years, the GFS starts it's usual trick of showing development, and then dropping it when it comes within 48 hours, also as it did the last two years. Nothing appears to have changed with the upgrades, the only change was that we didn't see the June error (which may have only been because something happened to form then.)

Even the last couple of seasons it would drop the Phantom Storms several days out, now when it's 48hrs. out.

[NDG]

Maybe the GFS got shy when it's phantom storm was given its own thread

[Siker]

Why is the GFS's new upgrade being not taken seriously when the wave hasn't even emerged? At least in other basins, the number of phantom GFS storms has been greatly reduced.

It's a bit hard to take seriously when about the same time as the last two years, the GFS starts it's usual trick of showing development, and then dropping it when it comes within 48 hours, also as it did the last two years. Nothing appears to have changed with the upgrades, the only change was that we didn't see the June error (which may have only been because something happened to form then.)

Even the last couple of seasons it would drop the Phantom Storms several days out, now when it's 48hrs. out.

People have commented this but I'm pretty sure the GFS did drop a few storms at this range in the past two years.

[TheStormExpert]

I'm sure it has, but this is the first one I've seen.

[wxman57]

Looks like the 06Z GFS dropped the storms in the Tropical Atlantic. Even if development occurred, any storm heading toward the Caribbean would be ripped apart by wind shear next week. The only chance for survival for a Cape Verde storm would be a track north of the Caribbean and likely out to sea east of the U.S.